Bio Final Flashcards

Question

substrates:

Answer 1

reactant molecules enzymes bring them together in a precise orientation so atoms involved in reaction can interact. 54 Many reactions can be activated by changes in temperature or acidity (low pH) — which are deadly to cells; cells use special proteins (enzymes) to perform complex synthesis and decomposition reactions in our body. (anat)

Answer 2

activation energy: the amount of energy required to start a reaction; required to break bonds in reactants so new bonds can form in products E^A Enzymes promote chemical reactions by lowering the activation energy required to make it possible for chemical reactions (ie. breakdown of sugars) to proceed under conditions compatible with life; they speed up reactions without themselves being changed or consumed — they proceed until equilibrium is reached. (anat)

Answer 3

spontaneous: downhill, degradative, catabolic, releases energy, moves from lower free energy to greater stability. spontaneous: happen on its own (break bonds) -- but can be slow. Heat works! 1. products are less ordered than reactants 2. products have lower potential energy than reactants

Answer 4

non-spontaneous products are more ordered than reactants reactants have lower potential energy than products require input of energy -- uphill!

Answer 5

energy is conserved (can’t be created / destroyed)

Answer 6

entropy increases in isolated systems

Answer 7

monosaccharide: “one sugar” — C3H603 1-2-1 C-H-O

Answer 8

(CH20)n ie. C1H2O1, C6H12O

Answer 9

two monosaccharides: disaccharide monomers called monosaccharide “one sugar” small polymers: oligosaccharides “few sugars” large polymers: polysaccharides “many sugars”

Answer 10

glucose is an example — cyclic structure forms a bond with oxygen atom and transfers its hydrogen to the carbonyl, turning it into a hydroxyl group; the newly formed Cq hydroxyl group can be oriented to produce alpha or beta glucose configurations:

Answer 11

sugars are synthesized on dust particles and other debris in interstellar space and could have rained down onto earth as the planet was forming as well as being synthesized in the hot water near ancient undersea volcanoes; synthesis of sugars could have been catalyzed by minerals found in walls of deep-sea hydrothermal vents

Answer 12

Most saccharides are readily synthesized under conditions that mimic conditions of early earth. ie. when formaldehyde molecules CH2O are heated in solution, they react with one another to form almost all the pentoses and hexoses.

Answer 13

They form when enzymes catalyze the formation of glycosidic linkages between monosaccharides that are in the alpha or beta form; they are long chains of monosaccharides, but some branch extensively; among linear forms, it is common for adjacent strands to be connected by hydrogen bonding or other types of linkages.

Answer 14

glycosidic linkage: monosaccharides polymerize when a condensation reaction occurs between 2 hydroxyl groups, resulting in a covalent interaction (analogous to peptide bonds in proteins, but peptide bonds form between same locations in their monomers, giving proteins a backbone structure, but this isn’t true with polysaccharides); glycosidic linkages form between hydroxyl groups and every monosaccharide contains at least 2 hydroxyls, the location and geometry of glycosidic linkages can vary widely!

Answer 15

1. serve as a substrate for synthesizing more complex molecules; ie. RNA contains 5-carbon sugar ribose and dnA contains modified sugar, nucleotides consist of ribose or deoxyribose, a phosphate group, a nitrogenous base Sugar acts as a subunit of each of these monomers. serve as precursor to larger molecules 2. provide fibrous structural materials: cellulose in cell walls of plants and algae; chitin: structural support in cell walls of fungi and external skeletons of insects & crustaceans; peptidoglycan: structural support in bacterial cell walls 3. indicate cell identity: immune system -- chains outside the cell membrane 4. store chemical energy: starch -- energy storage in root veggies and glycogen -- energy storage in animal cells

Answer 16

a polymer of B-glucose monomers joined by | B-1, 4-glycosidic linkages. each glucose monomer in the chain is flipped in relation to the adjacent monomer.

Answer 17

hydrolysis!

Answer 18

structural polymers tend to be repetitive, with 1 or 2 types of monosaccharides, but complex carbs are different. Some have enormous structural diversity — the linkages between them vary a lot. they are capable of displaying information to other cells through their structure. polysaccharides act as an identification badge on outer surface of plasma membrane that surrounds the cell. glycoproteins project outward from cell surface into environment glycoprotein: has 1 or more carb covalently bonded to it: cell recognition and cell-cell signaling; each cell has these on its surface that identify it as part of our body and not foreign — recognition and communication — ie. sperm only bind to eggs of their own species 79

Answer 19

polysaccharides like chitin (insects exoskeleton), and peptidoglycan form cell walls (bacteria), giving it structural strength,

Answer 20

catalysts: bring substrates together in a precise orientation that makes reactions more likely enzymes: speed up reactions like a lock and key — substrates fit into enzymes and react; very large compared to substrates and roughly globular. Enzymes are not rigid and static, but flexible and dynamic; many of them change shape and conformation when reactant molecules bind to the active site. 2. What is the activation energy (EA)? (Explain in terms of what this term means during the progress of a chemical reaction) What effects do enzymes have on the activation energy?

Answer 21

1. bring substrates together: when 1 or more substrates enter active site, they are held in place through H bonding or weak interactions with amino acids; once substrate is bound, 1 or more R groups come into play. the degree of interaction between substrate and enzyme increases and reaching maximum when temp unable condition (transition state) is formed — when the key is in the lock. 2. lower activation energy: activation energy: a certain amount of kinetic energy is required to strain the chemical bonds in substrates so they can achieve a transition state.

Answer 22

nitiation: enzymes orient reactions as they bind at spots within the active site transition: (facilitation) lower activation energy (moving) stabilized by a change in enzyme’s shape; interactions b/t substrate and R groups lower activation energy required for reaction termination: kick out products; reaction products have less affinity for active site, binding ends, enzyme returns to its original conformation and products are released. 147

Answer 23

1. temperature: affects folding and movement of enzyme and kinetic energy of its substrates 2. ph: concentration of protons in a solution affects structure and function — affects the charge on carboxyl and amino groups in residue side chains and the active site’s ability to participate in reactions that involve the transfer of protons or electrons 3. interactions with other molecules: other molecules (other enzymes) regulate most of the cell’s enzymatic activity — often changing the structure and their activity either activates or inactivates enzymes 4. modifications of its primary structure:

Answer 24

a) competitive inhibition: regulatory molecule is similar in size and shape to enzyme’s natural substrate and inhibits catalysis by binding to the enzyme’s active site — it competes with the substrate for access to the active site b) allosteric regulation: the regulatory molecule binds at a location other than the active site and changes the shape of the enzyme — binding event changes the shape of the enzyme that makes the active site available or unavailable.

Answer 25

chemical change in primary structure — reversible or not The changes often result from cleavage of peptide bonds that make up primary structure of enzymes. ie. Trypsin. Most comment: addition of one or more phosphate group — enzyme is phosphorylated instead of the substrate, and the transfer of a phosphate from ATP to the enzyme may be catalyzed by the enzyme itself or by a different enzyme. It adds a negative charge to one or more amino acid residues in a protein, electrons in that part of protein change configuration. enzyme’s conformation changes.

Answer 26

1. cofactors: inorganic ions (metal) which reversibly interact with enzymes 2. coenzymes: organic molecules that reversibly interact with enzymes (electron carries NADH FADH2) 3. prosthetic group: non-amino acid atoms or molecules that are attached permanently to proteins (ie. retinal, which converts light energy into chemical energy)

Answer 27

the change in enthalpy minus change in entropy multiplied by temperature in Kelvin.

Answer 28

1.H2, N2, HCN, NH3, CO2 present in atmosphere combine to form simple organic compounds 2. compounds react and form building blocks (aminos, sugars, nucleotides) 3. building blocks link to form larger polymers the first polymer replicated itself

Answer 29

nucleotides: nucleic acids are made up of monomers called nucleotides; have three components: Phosphate group, 5 carbon sugar (deoxyribose ribose), N-base

Answer 30

nucleotides: nucleic acids are made up of monomers called nucleotides; have three components: 1. phosphate group (bonded to sugar molecule) attached to 5’ carbon 2. a five-carbon sugar (bonded to the nitrogenous base); organic compound bearing reactive hydroxyl (-OH) functional groups 3. Nitrogenous base ATGC (U)

Answer 31

2 structural group the nitrogenous bases belong to: 1. purine: adenine and guanine (AG): two rings are linked together by 9 atoms (*think 9 and “nine” at the end of A and G) 2. pyrimidine: cytosine, thymine, (CT) and in RNA instead uracil (U): linked together by 6 atoms that make a single ring in each pyrimidine

Answer 32

Purines are large, made up of 9 atoms Pyrimidines are smaller, have a single molecule structure made up of 6 atoms, also include an RNA substituted U instead of T in DNA

Answer 33

1. drops an oxygen on 2’ carbon 2. has U instead of T 3. single strand instead of double

Answer 34

``` tRNA: translation mRNA: transcription rRNA: translation snRNA: transcript processing eukaryotes miRNA: micro-RNA -- piRNA + siRNA ```

Answer 35

directional: the sugar-phosphate backbone is directional— one end has an unlinked 5’ phosphate while the other has an unlinked 3’ phosphate — the groups aren’t linked to another nucleotide. DNA is always written from 5’-3’ direction which is the same way DNA and RNA are synthesized — bases are added only at the 3’ end of the growing molecule complementary trands are antiparallel: one strand is 5’->3’ and some are 3’->5’

Answer 36

carries information required for organisms growth and reproduction serves as a mold or template for synthesis of a complementary strand and contains information required for a copy of itself to be made.

Answer 37

AT GC bases are complementary: A-T pair has 2 hydrogen bonds G-C has 3 hydrogen bonds (making it stronger than AT)

Answer 38

1. primary: the order (sequence) of the different nitrogenous bases in a nucleic acid forms the primary structure of the molecule; hydrogen bond 2. secondary: 2 DNA molecules (strands) that run in opposite directions (orientations) of each other — twisted into a double helix, held together by hydrogen bonds by AT GC pairs and hydrophobic interactions that drive bases into the interior of the helix: hydrogen bonding, hydrophobicity, and van der waals interactions, phosphodiester linkages 3. tertiary: NONE

Answer 39

1. primary structure: consists of sugar-phosphate backbone formed by phosphodiester linkages and a sequence of 4 types of N bases extending from backbone. 2. secondary structure: This forms a hairpin structure — stem and loop configuration folds with unpaired bases on one side; complementary base pairing between purine and pyrimidine bases; A forms hydrogen bonds with uracil — 3 hydrogen bonds form between G and C and 2 hydrogen bonds form between A and U. They form hydrogen bonds on the same strand (rather than DNA second strand) — when bases on one part of RNA fold over and align with ribonucleotides on another part of the same strand, 2 sugar-P strands are antiparallel; hydrogen bonding b/t complementary bases results in stable double helix. 3. tertiary: folds that form distinctive three-dimensional shapes like tRNA; molecules are much more diverse in size, shape, reactivity than DNA

Answer 40

the potential energy of the nucleotide monomers is first raised by reactions that add two phosphate groups to the ribonucleotides or deoxyribonucleotides, creating nucleoside triphosphate: ATP = activated nucleotides; can be used to store and provide energy through high potential energy

Answer 41

The phosphodiester bond

Answer 42

Watson & Crick; X-ray crystallography Rosalind Franklin using DNA with X-rays and analyzing scattered radiation; Maurice Wilkins calculated distances b/t groups and molecules (Franklin-Wilkins), Erwin Chargaff — 2 empirical rules analyzing N bases in DNA samples from organisms

Answer 43

1. # of purines matches the # of pyrimidines | 2. # of Ts and As in DNA are equal and Cs and Gs in DNA are equal

Answer 44

VIRUS: To find out what the genes are made of that virus’s inject into cells to make them a host. Most people believed that it had to be proteins or DNA. By raising virus’s in a radioactive isotope of both phosphorus and nitrogen. The experimenter then had the virus attach to a host cell to starts replication. They then put the cells and virus capsids into a blender to separate them. They then centrifuged them which separated the solvents and a pellet. Between two samples of radioactive isotopes, they found that DNA was radioactive in the pellet of the test tube from the specific isotope it was raised in. Versus a different radioactive isotope that was found in the solution. This showed that DNA was being passed on from the virus, into the host cell.

Answer 45

coli: Predicted that DNA was synthesized in three possible ways: 1. conservative (old strands rejoin while new strands join) 2. semiconservative (old strand joins with a new strand), 3. dispersive: segments old and new; dispersive (segments of the old helix is removed and copied). By introducing an isotope of nitrogen during synthesia they were able to predict the traits of each generational offspring that each method would produce. The isotope of nitrogen is slightly heavier than neutral nitrogen so the density gradient of each generation will show a specific pattern for each method. The resulting density gradient conflicts with the conservative and dispersive method, but is consistent with the traits the semiconservative replication would produce.

Answer 46

1 .it builds off of RNA primer 2. builds in 3’ direction 3. it stops at edge of RNA primer

Answer 47

the last 50-100 nucleotides break off with each cell division telomeres: non-coding placeholders

Answer 48

DNA polymerase is unable to add DNA near tip, no synthesizing DNA without a primer — so single strand DNA stays single -- it has no template

Answer 49

Physical - UV radiation particles Chemical: carcinogens Biological: Virus

Answer 50

Nucleotide excision repair will detect the damaged nucleotide and use enzymes to remove and replace the nucleotide.

Answer 51

Xeroderma Pigmentosum is a hereditary disease that causes defects in the nucleotide excision repair mechanism which causes an accumulation of damaged DNA which will inevitably causes diseases such as cancer.

Answer 52

Hydrophobic (insoluble in water) Hydrocarbons: molecules containing only carbon + hydrogen (Many are carbon containing compounds found in living organisms and are nonpolar.)

Answer 53

Molecule that contains only Hydrogen + Carbon. | They are nonpolar: because the difference in electronegativity between hydrogen and carbon is less than 1

Answer 54

1. Energy storage: fats, fuelled 2. Cell membranes: Phospholipids 3. Cell Communication: Hormones (testosterone / estradiol)

Answer 55

the viscosity (the state of being thick, sticky, and semifluid in consistency) of the lipid bilayer of a cell membrane; 1. saturation: Having any double bonds as opposed to having all single bonds; 2. length of hydrocarbon chain

Answer 56

3 hydrocarbon chains joined to a glycerol head by ester linkages

Answer 57

fats phospholipids steroids

Answer 58

Saturated fats: (saturated with H) only single bonded carbons and hydrogens; single covalent bonds Unsaturated fats: 1 or more doubled bonded carbons, more fluid at room temperature because they create a kink in the chain which forces more space in between the lipid molecules;

Answer 59

1. energy storage 2. acts as pigment that capture or respond to sunlight 3. serve as signals between cells 4. form water proof coating on leaves and skin 5. act as vitamins used in many cellular processes

Answer 60

same: made up of hydrocarbon chains attached to a head. different: the head that hydrocarbon chains binds to: Phospholipids attached to a phosphate group Triglycerides attached to a glyceride head

Answer 61

contain both hydrophilic + hydrophobic elements. Hydrophilic heads interacts with water Hydrophobic tails interact with one another

Answer 62

I. Membrane is fluid and contains many proteins and lipids (things that move around). Enzymes move to where they need to (pathways) Receptors involved in cell communication can align with internal signaling molecules. II. Membrane is selectively permeable (things coming into and out of the cell are tightly regulated) Maintain proper pH and ionic concentrations for cellular reactions to occur Maintain electrochemical gradients necessary for cell signalling Helps control reaction timing and sequences

Answer 63

Selectively permeability : EASY: O2, CO2, N2 - They are small and nonpolar molecules are able to diffuse directly across the phospholipid bilayer. MEDIUM: H20 (small, uncharged polar molecules) HARDER: Glucose, sucrose HARD: Cl-, K+, and Na+ - Molecules that are large or polar will not diffuse across a phospholipid bilayer. Biologically important ions to know: Na+, K-, Cl-, Ca2+,

Answer 64

The cell membrane is “fluid” because: phospholipids move easily within the membrane, but they stay connected to each other because common hydrophobic tail and hydrophilic heads will try to stay connected as much as possible. Even if a phosphate bond is broken with another phosphate group they will quickly reform with other phosphate groups. It is important because: it allows the cell to be able to move and expand based on it’s needs and not break when it is bumped into or forced into a different area. If it did not bend and move base on outside input then it would be much more prone tearing and dying. The cell membrane is a mosaic because: proteins embedded in the phospholipid bilayer allow and control the rate of molecular exchange inside and outside the cell. Proteins can be amphipathic with nonpolar side chains in the middle of the protein and polar side changes on the exposed ends on either side of the cell wall.

Answer 65

Cholesterol maintains optimum membrane fluidity. This keeps the membrane functional in warm and cool conditions; reduces permeability at high temps, more dense, hydrophobic protects, insulates (permeability to glycerol is higher)

Answer 66

Intracellular: lots of PO4, Proteins, more K+, fewer Cl- Extracellular: More Cl-, More Na+, Less K+, Ca2+

Answer 67

Ion channels: move through channels down their concentration gradient and down their electrical gradient toward unlike charges

Answer 68

Estradiol and testosterone | Steroids are derived from cholesterol

Answer 69

Aquaporins (AQP): integral membrane proteins that serve as channels in the transfer of water, and in some cases, small solutes across the membrane. They are conserved in bacteria, plants, and animals.

Answer 70

passive transport / facilitated diffusion: down a concentration gradient; requires no energy -- small molecules, nonpolar (diffusion) active transport: up a concentration gradient, polar; requires energy / uphill

Answer 71

neuron: voltage gated channels, membrane potentials (charge difference across membrane) liver: ligand-gated channels -- lock and key

Answer 72

Ion gated channel: They respond to chemical and electrical signals in the cell. They tightly control the flow of ions through Voltage and Ligand gated channels. Structure of ion channels determine which ions travel through based on: size charge Ion channels: move through channels down their concentration gradient and down their electrical gradient toward unlike charges Examples: Voltage-gated channel sodium and potassium channels calcium channels Ligand-gated channel Nictotinic acetylcholine receptor (a special sodium channel)

Answer 73

“Diffusion of Water” from an area of high concentration to a low concentration.

Answer 74

Hypotonic: They will grow in size as they try to equalize with the outside solution. Hypertonic: They shrink in size in order to try and equalize with the outside solution. Isotonic: Nothing.

Answer 75

The cell membrane breaks down. Detergent breaks down the phospholipid bilayer of the cell. They separate proteins by breaking the phospholipids away.

Answer 76

Yes, but only through Active Transport

Answer 77

Downhill or spontaneous process, requires no input of energy

Answer 78

Uphill or nonspontaneous process, requires energy to occur. Ions move down concentration gradients. They also move down their electrical gradients(towards unlike charge) Ions respond to “Electrochemical Gradients”

Answer 79

-Is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consists of two parts, the electrical potential and a difference in the chemical concentration across a membrane.

Answer 80

Cystic Fibrosis is a mutation in the chloride channel CFTR (cystic fibrosis transmembrane conductance regulator); In 70-85% of CF cases, mutation is 3-bp deletion = loss of phenylalanine # 508; Mutations in gene encoding CFTR protein, eliminates its function Part of body affected: Build up in lungs, digestive tract, reproductive tract, tears How molecule affects function: Prevents transport of chloride (and indirectly sodium); Salts get retained intracellularly and the chlorine channel is non-existent or dysfunction, so chlorine is trapped inside and the sodium channels become overactive, pulling sodium in and stealing water from extracellular fluid (where the mucus is) which become hypertonic to extracellular fluid (in lungs, intestines, sweat glands, reproductive tract); Water is pulled from mucus lining in lungs.Mucus dries out and gets thick and cannot move properly.

Answer 81

sodium more on outside of cell, usually. When sodiums comes out of cell, they fit into shape, ATP comes and attaches and break sup phosphate groups and attaching to the protein changes shape and opens and allows K+ to fit if not same the shape of receptor and phosphate group is kicked off, therefore, the channel opens and K+ goes inside cell.

Answer 82

Maintains gradient and transport of K+ and Na+ ; it changes the shape so they can move in and out of the cell; It’s important because it pumps sodium out so the cell doesn’t lyse / explode. Potassium needs to be more inside the cell. Cell wants 140 concentration inside of K+. ``` Outside: Na+ Cl- (Chlorine) Inside more: K+ Ca+ ```

Answer 83

bacteria: organism - species - MRSA, staphylococcus archaea: organism - species - Thermophilia eukarya: organism - species - yeast, tetrahymena

Answer 84

Bacteria + archaea: ancient: oldest fossils are 3.5 billion years old abundant: most dominant forms of life by volume, we have more bacteria on our body than cells in our body; # of bacteria and archaea alive today 5X10^30 ubiquitous: in soils, oceans, organisms, form biofilms on surfaces diverse 1. abundance: diverse in the number of species and abundant -- 1 trillion cells in our body are outnumbered 10-1 by bacterial and archaeal cells living on and in you; a teaspoon of good quality soil contains billions of microbial cells; marine archaea = 10,000 individuals per milliliter in world’s oceans; bacteria and archaea living under the ocean makes up 10% of the world’s mass; number of bacteria and archaea alive today = 5X10^30; bacteria and archaea are the dominant life forms in terms of volume of living material 2. habitat diversity: they’re found almost everywhere; they live in environments where others can’t live (oxygen free mud, hot springs, salt flats), they are found as deep as 10,000 meters of seawater and at temps over 120 degrees; there are more prokaryotes than eukaryotes

Answer 85

: archaea - extreme environment lovers; they live in high-salt, high-temp, low-temp, or high pressure habitats enzymes isolated from some of these are used in research, forensics, sequencing tech, conservation genetics, food sciences, molecules research, evolution research example: an archaean grows close to hydrothermal vents that its surroundings are at 121C, a record high for life; it helps us understand the tree of life, develop industrial applications, and explore the structure and function of enzymes; the genomes of extremophiles have been sequenced and expeditions to seek new species because the first forms of life lived at high temperature and pressure environments and lacked oxygen -- this may explain how life on earth began and also give us evidence of extraterrestrial life. Also, enzymes that function at high temps and pressures may be useful in industrial processes enzyme: DNA polymerase Taq polymerase; Thermus aquaticus -- bacterium that lives in hot water springs in Yellowstone technology: PCR - Taq polymerase chain reaction in research and commercial settings - isolated from Thermus aquaticus, thermostable, tolerates rapid changes in temp, used to copy DNA in PCR, can make millions of copies before it loses activity properties: it’s stable up to 95C Types: OneTaq, Deep Vent, Top Taq, VeriQuest Taq, Terra PCR direct

Answer 86

1. origin of life 2. extraterrestrial life 3. commercial applications (taq poly) 1. medical importance: thousands of bacteria species live in and on our body, only a tiny fraction of those can disrupt normal body function “pathogenic”; pathogenic forms come from several different lineages, and tend to affect tissues at entry points of body (wounds, pores) in the respiratory and gastrointestinal tract and the urogenital canal. 2. bioremediation: using bacteria and archaea to clean up pollution to something less toxic and more processable .

Answer 87

Anthrax: autoimmune Firmicutes: staphlococcus/Streptococcus: affect nervous system, respiratory tract, skin, wounds, etc. disease: tetanus, acnes, shock, boils, pneumonia, strep throat, scarlet fever

Answer 88

Koch’s postulates: they define what is pathogenic (causes disease) microbe must be present in individuals suffering from disease and absent in healthy individuals organism must be isolated and grown in pure culture away from host organism if organism from pure culture are injected into a healthy experimental animal, disease symptoms should appear the organism should be isolated from the diseased experimental animal, again, grown in pure culture and demonstrated by size, shape, color to be the same as original organism.

Answer 89

laid the foundation for modern medicine, initially its greatest impact was sanitation -- efforts to prevent pathogen transmission

Answer 90

virulence: ability to cause disease is a heritable trait that varies among individuals in a population; natural selection operates on this trait. Some e.coli strains are harmless and some produce toxins that can kill cells in digestive tract

Answer 91

Extensive use of antibiotics in late 20th century in clinics and animal feed led to the evolution of drug resistant strains of pathogenic bacteria -- one study found that there are soil-dwelling bacteria in natural environments that actually use them as food. We may be entering the post-antibiotic era in medicine. Bacteria usually grow in biofilms (dense colonies enmeshed in polysaccharide-rich matrix helping shield them from antibiotics. Yikes: these are growing on catheters in hospitals! Ribosomal additions to protect themselves from anti-bacteria?/?/?/

Answer 92

metagenomics: way to study communities of microbes by sequencing their genomes. goal: The goal is to identify and characterize communities of organisms that are not able to be cultured in the lab (greater than 99%) environmental sequencing which allows biologists to rapidly identify and characterize organisms that have never been seen.; to document the presence of bacteria and archaea in the environmental sample that cannot be grown in culture determine profile of microbes that live in our bodies healthy people have different bacteria than sick ones key to using microbes to boost health

Answer 93

``` bioremediation: bacteria are placed in contaminated sites to assist in cleanup; bacteria consume/breakdown hazardous contaminants forming less toxic byproducts, also add nitrogen organic solvents wastewater oil spills chlorines / dioxins ```

Answer 94

Bacteria are diverse in structure size: range in size from smallest of free-living cells (“mycoplasmas” which are .015um^3) to the largest known (“thiomargarita namibiensis, 200X10^6 um^3); ie. one billion mycoplasma cells could fit into a namibiensis shape: filaments, spheres, rods, chains, spirals motility: many are motile, swimming movements using rotating flagella; they swim ahead or tumble, which allows them to change directions; gliding movement (creep along surface) Bacteria are diverse in metabolism -- they produce ATP in 3 ways: page 538 phototrophs: “light feeders” use light energy to excite electrons. ATP is produced by photophosphorylation: Chemoorganotrophs: oxidize organic molecules with high potential energies (ie. sugars) Chemolithotrophs:oxidize inorganic molecules using ammonia and methane

Answer 95

Gram positive | gram negative

Answer 96

Autotroph: self-feeders synthesize building blocks from simple molecules( cO2 / CH4) organisms that manufacture their own building block compounds Heterotroph: other-feeders absorb organics from environment (and other orgs) organisms that acquire building block compounds from other organisms

Answer 97

all eukaryotes that aren’t plants, animals, and fungi. They are multicellular and most are unicellular; they don’t make up a monolithic group; represent some of single common ancestor;

Answer 98

Found: environments surrounded by water: ie. wet soils, aquatic habitats, inside bodies of other organisms Why studied: medically: cause disease like malaria, food crops, parasites in humans, algal blooms, drug resistance ecologically: aquatic food chains, climate change evolution: understand evolution of life on earth

Answer 99

Leishmania: causes skin sores / affect internal organs - spleen and liver Malaria: most infection disease in world; enters through blood - infects liver cells and in your brain. Phytophthora infestans: responsible for irish potato famine giardia: diarrhea can last several weeks

Answer 100

algal blooms: unicellular species have rapid population growth due to photosynthetic protists (dinoflagellates) -- some synthesize toxins to protect themselves from predation by copepods. Have high concentrations of pigments (xanthophylls) which discolor water. toxins released by dinos build up in shellfish (paralytic shellfish poisoning where saxitoxin blocks ion channels -- weakness + paralysis) Red Tides: caused by algal bloom: Shell fish poisoning -- feeding on protist-fed shellfish; saxotoxins block ion channels and it affect nerve cells (block signal from travelling); muscle weakness, paralysis, prickling sensation ni mouth Why concerned: harmful to people because clams and shellfish filter protists out of the water as food, which causes high levels of toxins to build up. Saxitoxins -- cause prickling in mouth, muscle weakness, and paralysis.

Answer 101

Prokaryotes: (Bacteria/Archaea) -- small, nucleoid (DNA location), few permanent internal membranes, no nuclear membrane (nor mitochondria), DNA circular, binary fission/budding reproduce, rotating flagella, cytoskeleton proteins help cell division, cytoplasm contains all contents of cell different than outside, cell wall counteracts forces of osmosis (gives shape + rigidity) -- may be polysaccharide on outside) Eukaryotes: large, DNA in nucleus, membrane-bound parts, DNA linear, mitosis/meiosis reproduce, tubulin cilia flap

Answer 102

endosymbiont theory: symbiotic relationship allowed host to occupy new environments with oxygen. mitochondria originated when a bacterial cell took up residence in another cell 2 billion years ago Proposed by: Lynn Marguilus: proposed that modern mitochondria are remnants of ancestral aerobic bacterium that took up residence in archaeal host. Evidence: mutual advantage: host supplied bacteria with protection and carbon compounds from prey bacterium produced much more ATP than the host cell could synthesize on its own evidence slides: mitochondria are same size as bacteria have their own circular DNA molecules (like bacteria) have their own ribosomes which are poisoned by same antibiotics that inhibit bacterial ribosomes have double membranes consistent with engulfing mechanism divide by binary fission as bacteria do

Answer 103

1. membrane infoldings surround chromosomes 2. eukaryotic cells arises with enfoldings forming nuclear envelope and ER; enfolding became detached from plasma membrane, giving rise to ER and nuclear envelope infoldings of plasma membrane led to development of the membrane bound organelles -- nuclear envelope, ER, golgi, mitochondria, chloroplasts

Answer 104

photosynthetic eukaryotic cells: The photosynthetic protist was engulfed by predatory protist, nucleus formed from photosynthetic protist (which was lost in process), organelle has four membranes. Evidence: chloroplasts have bacteria-like characteristics (same as mitochondria list) modern examples of cyanobacteria living inside protists and animals

Answer 105

cytosol: fluid between plasma membrane and organelles -- small volume. small volume of cytosol reduces the effect of total surface area to volume ratio (exchange of nutrients and waste products)

Answer 106

golgi apparatus endoplasmic reticulum lysosomes

Answer 107

ontain hydrolytic enzymes break down macromolecules into building blocks to be reused by cell; hydrolases function at pH5; used in phagocytosis + recycling cellular organelles; found only in animal cells

Answer 108

Build up of a lipid that is normally broken down in the lysosome of cells in CNS Tay-sachs: lipis build up around nerve cells because they are not broken down in the normal way. Infants losing sight, hearing, and movement, death usually within 3 years.

Answer 109

protein synthesis, proteins produced here end up in the plasma membrane, secreted from cell

Answer 110

lipid synthesis detox stores CA2+ for cell signalling

Answer 111

globular organelles that are centers for reduction oxidation; single membrane + originate as buds in ER. byproducts include H202 enzymes that oxidize h202 into water and oxygen If it didn’t have a membrane, it would just eat up all the cell’s parts.

Answer 112

Mitochondria is where ATP is made during cellular respiration; How structure allows it to perform its function: double membrane inner membrane folded into cristae -- contains proteins in electron transport chain + ATP synthase innermost region is matrix

Answer 113

Organelles in plants and most algae where sunlight converted into energy double membrane membrane-bound stacks of thylakoids structural proteins, pigments, and enzymes responsible for photosynthesis are embedded in thylakoid membranes

Answer 114

actin filaments: strands with double helix (microfilaments) / acting intermediate filaments: fibers wound into thicker cables // keratin, lamin, others microtubules: alpha and beta tubulin

Answer 115

actin myosin dynein

Answer 116

To make energy quickly -- oxidizing glucose to make ATP (energy released is used to make ATP)

Answer 117

Cellular respiration has nothing to do breathing. Ventilation does. Cellular respiration is the process of making energy from glucose.

Answer 118

1. glycolysis: occurs in cytoplasm of eukaryotes and prokaryotes; one 6-carbon molecule of glucose is broken into pyruvate (two molecules of 3-carbon compound), ATP is produced from ADP and NAD is reduced to make NADH. 2. pyruvate processing: occurs in matrix of mitochondria or cytoplasm of prokaryotes; pyruvate is processed (oxidized) to release one CO2 molecule and remaining two carbons are used to form acetyl CoA -- results in more NAD+ being reduced to NADH 3. citric acid cycle (KREBS): to two molecules of CO2, more ATP and NADH are produced and FAD is reduced to form FADH2 4. electron transport and oxidative phosphorylation: occurs in inner membrane of mitochondria or plasma membrane of prokaryotes; electrons from NADH and FADH2 move through proteins (ETC - electron transport chain) -- energy released in chain of redox reactions is used to create a proton gradient across the membrane; protons flow back across the membrane to make ATP (this mode links the phosphorylation of ADP with oxidation of NADH and FADH2)

Answer 119

1. glycolysis: 10 reactions, happens in cytoplasm // glucose goes in, 2 pyruvate comes out 1st 4 reactions: energy investment! (using ATP to start reaction), 1st + 3rd requires input of energy (2 ATP molecules), starts with 6-carbon molecules that gets split into two 3-carbon molecules; 2nd 5 reactions: energy payoff! 2 NAD+ molecules get reduced into 2 NADH molecules, also 2 ATP (net) molecules getting made; 2 NADH + 2 ATP (net) energy produced) ; 6th NAD+ ---> NADH // 7th + 10th generate 4 ATP (2 each), 2 actually gained along with 2 pyruvate = enzyme catalyzes transfer of ADP to ATP where: cytoplasm input: glucose output: pyruvate energy: 2 ATP substrate level phosphorylation: enzyme reactions resulting in ATP production 2. pyruvate processing: take 2 pyruvates to make 2 CoA out and 2 NADH out(no ATP) where: matrix of mitochondria input: pyruvate output: 2 Acetyl CoA energy: 2 NADH 3. Krebs/Citric Acid: redox reaction; to two molecules of CO2, more ATP and NADH are produced and FAD is reduced to form FADH2 where: matrix of mitochondria input: 2 Acetyl CoA output: 2 (4????) CO2 energy: 6 NADH, 2 FADH 2, and 2 GTP (later gets turned into ATP) 4. oxidative phosphorylation / electron transport: final electron acceptor is O2 where: inner membrane of mitochondria input: NADH (complex 1) + FADH 2 (complex 2) ---> (complex 3) ---> (electron donated to make 02) output: 25 H+s + 0 + electron makes H20 energy: makes 25 ATP.

Answer 120

in intermembrane space -- Higher H+ concentration outside than inside, the H+ from the outside go in through ATP synthase and move rotor and connects phosphate group to ADP to make ATP. Makes 25 ATP. ATP Synthase: chemiosmosis: process of cranking out ATP into the matrix

Answer 121

redox: reactions are assisted by enzymes reduction :molecule is “reduced” by gaining electrons. They often are accompanied by protons, so look for molecules that gain hydrogen ions. oxidation: molecule is “oxidized” when it loses electrons (and maybe lose hydrogens too) Oxidation: energy rich molecule to product enzymes that use NAD++ as cofactor for oxidation reactinos bind NAD+ and the substrate 2 electrons and proton are transfered to NAD+, forming NADH; second proton is donated to the solution NADH diffuses away and donates electrons to other molecules reduction: product to energy rich molecule; opposite of above?

Answer 122

substrate level phosphorylation: when an enzyme catalyses a reaction that results in the production of ATP; reactions 7+10 -- transfer of phosphate group from substrate to ADP to form ATP in cells, enzymes routinely break down fats to release the glycerol and convert the fatty acids into acetyl CoA molecules; glycerol can be processed and enter glycolysis; acetyl CoA enters the citric acid cycle

Answer 123

Phosphorylation uses the electron transport chain during this process--you get 2 ATP out of it (4?) -- bulk of ATP comes through chemiosmosis (like 34 ATP!) … movement of electrons generate this

Answer 124

To make energy without oxygen.

Answer 125

NADH | FADH2

Answer 126

ATP and GTP

Answer 127

2 ATP, 2 NADH (is NADH a nucleotide?)

Answer 128

The matrix of the Mitochondria. 2 Acetyl-CoA.

Answer 129

6 NADH | 2 FADH 2

Answer 130

2-Pyruvate feed in. 2 Acetyl and 2-CO2 CoA come out.

Answer 131

6-NADH and 2 FADH2

Answer 132

2-GtP (later converted into ATP),

Answer 133

NADH gives up electrons to Complex I. FADH2 gives up electrons to Complex 2.

Answer 134

Complexes 1,3,4 pump H+ against their gradient into the intermembrane space. They are being pumped into the intermembrane space.

Answer 135

The total number of ATP=29. 2 From Glycolosis, 2 from Citric Acid Cycle, and 25 from Chemiosmosis.

Answer 136

2 ATP through alcohol fermentation. Yeast are Eukaryotes.

Answer 137

1. DNA synthesis 2. To separate chromosomes during Anaphase 3. to pump elements across the cell membrane that are too large to diffuse, polar, or against their gradient.

Answer 138

evidence slides: mitochondria are same size as bacteria have their own circular DNA molecules (like bacteria) have their own ribosomes which are poisoned by same antibiotics that inhibit bacterial ribosomes have double membranes consistent with engulfing mechanism divide by binary fission as bacteria do

Answer 139

the cell that results from fertilization; when two haploid gametes fuse during fertilization, a full complement of chromosomes is restored

Answer 140

having one set of chromosomes; a cell or individual with one set of chromosomes

Answer 141

having two sets of chromosomes; a cell or individual organism with two sets — one from mother and one from father

Answer 142

the state of having an abnormal number of copies of a certain chromosome

Answer 143

gap between end of M and start of S phase

Answer 144

class of proteins whose major function is to convert the chemical energy of ATP into motion -- dynein, kinesin, myosin

Answer 145

a protein that prevents cell division, such as when cell has DNA damage -- mutant genes that code for tumor supp. are associated with cancer

Answer 146

(slide) proteins required for normal cell growth -- if mutated they become active when they shouldn’t be -- uncontrolled cell growth = cancer

Answer 147

any gene whose protein product stimulates cell division at all times and thus promotes cancer development; often mutated form of a gene involved in regulating cell cycle

Answer 148

any several related protein kinases that are functional only when bound to a cyclin and are activated by other modifications; involved in control of cell cycle; cannot’ be switched off! They can be phosphorylated and inactivated; as cyclin concentrations decrease, CDKs become inactive

Answer 149

a complex of cyclin and dependent kinase that, when activated, phosphorylates a number of specific proteins needed to initiate mitosis in eukaryotic cells

Answer 150

process where haploid daughter cells, each containing one of each homologous chromosomes eventually go on to form egg cells or sperm cells

Answer 151

the structure formed by synapses homologous chromosomes during prophase of meiosis I

Answer 152

if both homologs in meiosos I or both sister chromatids in meiosis II move to same pole of parent cell, the products will be abnormal

Answer 153

cells have too many or too few chromosomes of particular type

Answer 154

the state of having only one copy of particular type of chromosome in an otherwise diploid cell

Answer 155

1. growth 2. wound repair 3. reproduction

Answer 156

prokaryotic: divide by binary fission whenever nutrients available and cells are large enough eukaryotic: nuclear division cell cycles -- somatic cells divide to produce 2 genetically identical daughter cells / and division for germ line cells to produce genetically different haploid gametes

Answer 157

spindle apparatus forms: composed of microtubules originating from microtubule organizing centers (centrosome w/centrioles in animal cells); they move chromosomse vesicles from golgi apparatus carry components to build a new cell wall using these polar microtubules via motor proteins; the furrow appears because a ring of actin filaments forms just inside membrane -- myosin motor proteins bind to these actin filaments and use ATP to contract in a way that cause actin filaments to slide; myosin moves the ring of actin on the inside of membrane, the ring shrinks in size and tightens. Actin and myosin filaments slide past each other, tightening the ring further, until original membrane pinches in two and cell division is complete.

Answer 158

DNA wrapped around globular histone proteins-- chromatin; during interphase, the chromatin is relaxed / uncondensed, forming long, thin strands.

Answer 159

intestine: 2 times a day neuron + muscle: many do not divide liver cells: replicate once per year. If liver is damaged, remaining cells divide every 1-2 days.

Answer 160

Synthesis phase: DNA replication before a cell can divide (meiosis / mitosis) the DNA must be replicated so there will be enough for daughter cells. G1 + G2: growth, replicating organelles and increase in size G1: determines if cell will go through cycle and divide or exit; size: daughter cells large enough to function nutrients available social signals: signalling molecules from other cells (social signals) damage to DNA: physical damage -- repairable or not / apoptosis G2: After S phase: DNA damaged or chromosomes not replicated correctly -- removable of inactivating phosphate blocked; when MPF is not turned on, cells remain in G2; related to size, too M-Phase: (2) kinetochores attached properly to spindle apparatus; chromosomes might not separate correctly

Answer 161

kinase: polypeptide subunit catalyzes transfer of phosphate group from ATP to target proteni (regulatory protein)

Answer 162

appears to signal “start M phase” maek of distinct polypeptide subunits -- concentration of kinase is more or less constant throughout cycle; cyclins: their concentrations fluctuate throughout cell cycles; concentration of cyclin associated with MPF during interphase and peaks in M phase; timing is key, MPF is only functional when bound to cyclin (which regulates MPF dimer) kinase: catalyzes transfer to a target protein cyclin: regulates MPF dimer MFP is a CDK: activates proteins necessary to start M-phase by phosphorylating them molecule that initiates mitosis was M-phase promoting factor is a type of cyclin-dependent protein kinase (CDK) kinases put a phosphate group on target proteins CDKs phosphorylate proteins that are necessary for the next stage: types PF activates proteins necessary to start mitosis another maintains cells in G0 phase activates proteins necessary to push cell from G1 into S Important to regulate: because of cancer Pronto-oncogenes: two types of defects cause cancer Ex: defective Ras protein triggers uncontrolled cell growth

Answer 163

Mitosis: two sister chromatids separate into separate genetically identical daughter cells; 5 phase: prophase: chromosomes condense -- DNA wraps tightly around histones and scaffolding proteins (tightly packed); prometaphase: nuclear envelope breaks down, microtubules contact kinetochores metaphase: chromosomes all line up independently at the metaphase plate (middle”), spindle apparatus complete (centrioles at opposite poles of cell) anaphase: sister chromatids separate into daughter chromosomes and are pulled apart telophase: nuclear envelope reforms, chromosomes de-condense cytokinesis: in plant cells, cell plate forms in location of metaphase plate // in animal cells, furrow forms (actin and myosin contractile ring constricts cytoplasm)

Answer 164

Mitosis: 1. cell divisions: 1 2. # of chromosomes in daughter cell compared to parent: same 3. synapsis of homologs: no 4. # of crossing over: none 5. makeup of chromosomes in daughter cells: identical 6. role: asexual reproduction in some eukaryotes, cell division for growth 7. homologous chromosomes pairing timing: don’t pair at all 8. align @ plate: individual chromosomes line up single file 8. result: identical daughters Meiosis: 1. cell divisions: 2 2. # of chromosomes in daughter cells compared to parent: half 3. synapsis of homologs: 1 + per pair of homologous chromosomes 4. # of crossing over: different - various combos of maternal/paternal chromosomes, both are mixed within chromosomes 5. role: 1/2’ing chromosomes in cells that produce gametes 6. homologous chromosomes pairing timing: early 7. align @ plate: homologous paired up result: non-identical daughters (unique)

Answer 165

independent assortment crossing over random fertilization random mating

Answer 166

somatic cell: 23 | human gamete: 46

Answer 167

nondisjunction: when sister chromatids in meiosis II move to same pole -- homologs / sister chromatids fail to separate (disjoin) aneuploidy: too many or too few chromosomes

Answer 168

Patau Syndrome: Kinefelter Syndrome: Turner Syndrome: Down Syndrome: 23

Answer 169

Autosomal vs. Sex-linked: If a trait appears about equally often in males and females, then it’s likely to be autosomal; but if males express trait more often, then alleles responsible is likely to be recessive and found on X chromosome. X linked recessive traits: males express trait more often than females; appearance of X-linked recessive usually skips a generation in pedigree. Most X-linked traits are recessive. 278 X-linked dominant: an affected male will pass the trait to all his daughters and none to his sons; because daughters have their father’s only X chromosome; heterozygous female will pass the trait to 1/2 daughters and 1/2 sons Y-linked traits: very few genes occurs on Y. They are involved with male specific sexual development; there are no known human Y-linked traits.

Answer 170

the combination of alleles on X chromosome is different from combinations of alleles present in the mother

Answer 171

Genes that are very close together are less likely to separate during crossing over

Answer 172

Environment: an individual's phenotype is often as much a product of environment as it is a product of genotype: temp sunlight nutrients available competition mother’s hormone levels during development of embryo 2. Interactions between genes: genes work together to control a single trait when gene-by-gene interactions occur, one trait is influenced by alleles of two or more genes one gene influences many traits: pleiotrophic

Answer 173

quantitative traits: continuously varying traits that don't like to fall into one category; are produced by the independent actions of many genes (some have greater effects than others); are greatly influenced by environment; when the frequency of different trait values observed are plotted on histogram (freq. distribution), they often form a bell shaped curve (normal distribution) p 275

Answer 174

polygenic inheritance: each gene adds a small amount to the value of the phenotype; this is why offspring resemble their parents; ie. blood pressure

Answer 175

pleitrophic: gene that influences many traits — more genes influence more than 1 trait; ie. mutations in one gene cause Marfan syndrome; FBN1 alleles is dominant to wild-type alleles; people with FBN1 are tall, have long limbs, fingers, abnormally shaped chest, heart problems, etc.

Answer 176

they evenly get split apart and all the options are the same...ie Bb x 4

Answer 177

they can swap -- there are multiple options - 3 different options

Answer 178

3’ CGUACGUAUGCUGAAUUAC 5’ | 5’ GCAUGCAUACGACUUAAUG 3’

Answer 179

many genes code for RNA molecules that do not function as mRNAs, they are not translated into proteins info sometimes even flows from RNA back to DNA. ie. reverse transcriptase: when RNA viruses infect a cell, this polymerase synthesizes a DNA version of RNA genes; ex: AIDS / HIV -- uses reverse transcriptase

Answer 180

Stop codons / start codons specify methionine | introns

Answer 181

transcription: making a copy of information; conveys the idea that DNA acts as a permanent record -- an information archive or blueprint, which is copied, during transcription, to produce short-lived form (mRNA) translation: converting info from one language to another; the transfer of info from one type of molecule to another -- from language of nucleic acids to language of proteins -- also referred to simply as protein synthesis; Roles of transcription & translation: DNA is transcribed to RNA by RNA polymerase; Transcription: is the process of copying hereditary info in DNA to RNA Messenger RNA is translated to proteins in ribosomes; translation: is the process of using the information in nucleic acids to synthesize proteins

Answer 182

large subunit: forms E, P, A binding sites for tRNA, channel for growing polypeptide, area to catalyze formation of peptide bonds small subunit: binds to mRNA + provide site for complementary binding b/t anticodon on tRNA + codon on mRNA

Answer 183

small subunit

Answer 184

RNA polymerase: enzyme / protein that catalyzes the synthesis of RNA; it synthesizes RNA molecules according to the information provided by base sequences in particular stretch of DNA’ 5’-3’ direction, do not require a primer The sequence of bases in DNA specifies the sequences of bases in an RNA molecules, which specifies the sequence of amino acids in a protein; genes ultimately code for proteins DNA polymerase: 5’-3’ direction, require a primer to begin transcription

Answer 185

promoters: sections of DNA that promote the start of transcription promoters vary more than bacterial promoters; most include a sequence (TATA box) centered 30 base pairs upstream of transcription start site transcription begins when basal transcription protein factors (like a sigma) bind to a promoter — in response, RNA polymerase binds to site; They assemble at the promoter, and RNA polymerase follows 320 initiating transcription: initiation: where and in which direction transcription takes place on DNA template; promoters: sections of DNA that promote the start of transcription; transcription begins when basal transcription protein factors bind to a promoter — in response, RNA polymerase binds to site; They assemble at the promoter, and RNA polymerase follows also: elongating polypeptide: RNA polymerase begins moving along the DNA template synthesizing RNA terminating translation: transcription terminates after RNA is cleaved downstream of poly(A) sequence; eventually, RNA polymerase falls off; termination: transcription stops when RNA polymerase transcribes a DNA sequence that functions as a termination signal — as soon as its synthesized, this portion of RNA folds back on itself and forms a short double helix held together by complementary base pairing (hairpin structure)

Answer 186

Prokaryotes: sigma: detachable protein subunit binds to polymerase before transcription begins; makes the initial contact with the DNA of the promoter; Prokaryotes: termination: transcription stops when RNA polymerase transcribes a DNA sequence that functions as a termination signal — as soon as its synthesized, this portion of RNA folds back on itself and forms a short double helix held together by complementary base pairing (hairpin structure) Eurk transcription terminates after RNA is cleaved downstream of poly(A) sequence; eventually, RNA polymerase falls off; hairpin forms and changes interactions with polymerase

Answer 187

RNA processing: occurs in nucleus; any modification (such as splicing or polyA tail addition) needed to convert a primary transcript into mature RNA; primary transcript: the initial product when genes of any type are transcribed — pre-mRNA. must be processed to produce a mature RNA 321 in these transcripts, stretches of RNA (introns) are spliced out and exons are joined together ALSO: Splicing: introns are removed from growing RNA strand; pieces of primary transcript are removed and remaining segments are joined; occurs in nucleus while transcription is underway and results in RNA that contains uninterrupted genetic message. Four steps: snRNPs bind to 5’ exon-intron boundary (marked by GU) to key A near end of intron other snRNPs arrive to form multipart spliceosome, which contains 145 proteins and RNAs intron forms loop plus single-stranded stem (lariat) with A at its connecting point lariat is cut out, a phosphodiester linkage links eons on either side, producing continuous coding sequence (the mRNA)333 cap & tail: serve as recognition signals for translation and protect the message from degradation y ribonuclease (makes mature mRNA) 323 function: protect mRNAs from degradation by ribonucleases (enzymes that degrade RNA) and enhance the efficiency of translation 324

Answer 188

codon: group of 3 bases that specifies a particular amino acid — many of the 64 codons that are possible might specify the same amino acid

Answer 189

translation: protein synthesis initiation: // ribosome binding site / Shine-Dalgarno Sequence: 3 steps: a. mRNA binds to small subunit (ribosome binding site sequence binds to complementary sequence in an RNA molecule in small subunit helped by initiation factors - promoter / basal transcription factro; b. initiator aminoacyl tRNA binds to start codon c. large subunit of ribosome binds, completing ribosome assembly, translation can now begin 329 elongation: extending when both the P site and the A site are occupied by tRNAS and the amino acids on the tRNAs are in the ribosomes active site; this is where peptide bond formation occurs; 3 steps: a. arrival of aminoacyl tRNA b. peptide bond formation c. translocation (repeat down the length of mRNA). RNA polymerase adds nucleotides. Splitting phosphate groups from NTPs provides energy for transcription termination: Termination signal in DNA is transcribed into mRNA & causes all to disassociate; release factor: polyA -- cap and tail, migrates to ribosom ; recognizing the stop codon and files the A site when translocating ribosome reaches one of the stop codons — UAA, UAG, UGA 331

Answer 190

point mutation: a single-base change — if a mistake is made during DNA synthesis or DNA repair, a change in sequence of bases results 313 reading frame: single addition or deletion mutation throws the sequence of codons out of register; Crick + Brenner: confirmed that codons are 3 bases long; also were able to produce DNA sequences that had deletions or additions of 2 base pairs or 3 base pairs

Answer 191

mutation: any permanent change in organisms DNA — modification in a cell’s information archive — a change in genotype, mutations create new alleles point mutation: a single-base change — if a mistake is made during DNA synthesis or DNA repair, a change in sequence of bases results

Answer 192

point mutations that case changes in amino sequence of proteins (ie, like forest mice colonized beach habitats, altered melacortin receptor gene resulting in whiter rat coats, camouflaging them in beaches, and the alleles created by point mutation increased frequency in beach-dwelling populations) 313

Answer 193

a point mutation that doesn’t change the amino acid sequence of the gene product

Answer 194

major disruptions of proteins — single addition or deleting throw off sequence of codons out of register and alters meaning of all subsequent codons

Answer 195

large effecting — occur when codon that specifies amino acid is changed by mutation to one that specifies a stop codon — causes early termination of polypeptide chain and results in non-functional protein.

Answer 196

beneficial: increase fitness of the organism — its ability to survive and reproduce — in certain environments; the G-to-A mutation is beneficial in beach habitats because it camouflages mice neutral: no effect on fitness — silent mutations are usually neutral deleterious: because organisms tend to be well-adapted to environment, and mutations are random changes in genotype, many lower fitness; they are harmful or deleterious. G-to-A mutation would be deleterious in forest habitat 313

Answer 197

Allows right amino acid to be attached: input of energy - ATP to attach amino acid to tRNA enzymes: aminoacyl tRNA synthetase catalyzed addition of amino to tRNAs “charging” a tRNA -- the combo of tRNA molecule covalently linked to an amino acid; this synthetase bound to a tRNA has just been charged with an amino acid, so the two structures fit together tightly, making it possible for enzyme and it’s tRNA and amino acid substrates to interact in a precise way. 327 for each 20 aminos, there is a different synthetase and one or more tRNAs Subtle shaped and base sequenced allow enzymes to recognize correct tRNA for correct amino acid.

Answer 198

anticodon and codon (mRNA/tRNA) are complementary; Each aminoacyl-tRNA synthetase has a binding site for a particular amino acid and a particular tRNA; subtle differences in shape and base sequence allow enzymes to recognize the correct tRNA for the correct amin

Answer 199

translocation: occurs when proteins (elongation factors) help move the ribosome relative to the mRNA so that translation occurs in the 5’—>3’ direction, requires GTP! 331

Answer 200

``` chromosome mutations: inversion translocation deletion duplication ```

Answer 201

beneficial: beach mouse G-to-A mutation neutral: silent deleterious: G-to-A would be bad in forest

Answer 202

No, some are neutral (no negative effect, a change that gives the species a similar adapatability to its environment) and others are beneficial (beach mouse)

Answer 203

Mendel: established basic patterns of inheritance, independent assortment, recessive/dominant 266 (discovered chromosomes contain genes that can be inherited) Morgan discovered: X-linked inheritance — chromosomes contain genes and can be inherited! 269

Answer 204

X-linked traits (and as a result sex-linked and Y linked traits, too)

Answer 205

All the F1 had red eyes; in continued crosses, he obtained white-eyed female flies; when reciprocal cross: b/t white-eyed female and red-eyed male, all F1 females had red eyes, but all F1 males had white eyes. 268

Answer 206

principle of segregation: reappearance of recessive phenotype and 3:1 ratio in F2 individuals — 2 members of each gene pair must segregate into different gamete cells during formation of eggs and sperm; each gamete contains one allele of each gene 262 independent assortment: alleles of different genes are transmitted independently of one another 265

Answer 207

Beadle & Tatum: thought that we should be able to discover what genes do by making them defective; knock out a gene by damaging it and then infer what gene does by observing the phenotype of the mutant individual 305 found N.crassa mutants that could not make certain compounds one mutant could not make pyridoxine (B6) even tho normal ones can. Inability to synthesize pyridoxine was due to a defect in a single gene -- the inability to synthesize other molecules was due to defects in other genes results inspired one-gene, one-enzyme hypothesis -- the N.crassa lacked the enzyme due to a genetic defect and was unable to synthesize the compound implication: knock-out mutant studies showed that each gene contains info needed to make an enzyme

Bio Final Flashcards

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