Week 1 Textbook Flashcards

Question

explain the structure and function of chloroplasts

Answer 1

structure - large green organelles that are found in plants and algae contains their own DNA and uses cell division to grow/reproduce said to have evolved from photosynthetic bacteria that was living inside a eukaryote already with a mitochondria - more complex than mitochondria in structure - they have 2 surrounding membranes + internal stacks of membranes containing green pigment - chlorophyll = photosynthesis function - photosynthesis - chloroplast traps the energy of sunlight to create sugar molecules - plant cells can extract this stored energy when needed by oxidizing the sugar - a by-product = oxygen - enable plants to get energy from sunlight to produce food molecules + oxygen that the mitochondria use to generate chemical energy in the form of ATP

Answer 2

structure - irregular maze of interconnected spaces enclosed by a membrane function - the site where most of the cell components are made to be exported from the cell good for cells that are specialized to secrete large amounts of protein

Answer 3

structure - stacks of flattened sacs that are enclosed by membranes function - modifies and packages molecules made in the ER that are destined to be either secreted from the cell or transported to another cell compartment

Answer 4

structure - small, irregularly shaped organelles function - intracellular digestion occurs - releasing nutrients from ingested food particles into the cytosol/cytoplasm and breaking down unwanted molecules for recycling or excretion from the cell

Answer 5

structure - small, membrane-enclosed vesicles function - provide a sequestered environment for a variety of rxns in which hydrogen peroxide is used to inactivate toxic molecules

Answer 6

imported materials are grouped to form an endosome - a membrane-encoded organelle (when they are being delivered by endocytosis)

Answer 7

endocytosis - across the plasma membrane, they import extracellular materials by endocystosis by using small membrane-bound endosomes exocytosis - the cell secretes intracellular materials by exocytosis via endsomes - most of the hormones and signal molecules that allow cells to communicate with each other = exocytosis

Answer 8

structure - the cytosol is part of the cytoplasm that is not contained within intracellular membranes largest compartment water-based gel than a liquid solution because it holds large and small molecules close together functions - its of many chemical reactions that are fundamental to the cell's existence - breakdown of nutrient molecules takes place in the cytosol

Answer 9

structure - a system of long fine crisscrossed filaments in the cytoplasm of a eukaryotic cell - the cytoskeleton is continually assembling, disassembling function - gives the cell shape and capacity for directed movement - composed of 3 major filaments (actin filament, microtubules, intermediate filaments) - gives the cell its mechanical strength, controls shape, guides and directs movements - in plant cells - chloroplasts and mitochondria move along cytoskeletal tracks = cytoplasmic streaming - the rate of streaming it affected by light, temp, pH

Answer 10

actin filaments - thinnest + very abundant and used a lot inside muscle cells = central part of machinery responsible for muscle contraction used in amoeba to crawl around using actin polymerization - growing actin filaments push out pseudopods (feet) - organelles also move with it on cytoskeletal tracts microtubules - thickest + hollow tubes - in dividing cells they become reorganized into an array that helps pull the homologous chromosomes apart and distribute them evenly between the 2 new daughter cells being made intermediate filaments - medium thickness + strengthens animal cells overall the 3 types work together to make a system of ropes, motors and girders for the cell

Answer 11

they used the energy stored in molecules of ATP to trundle along these tracks and cables + carry organelles and proteins throughout the cytoplasm

Answer 12

a cell that inhabits connective tissue and deposits extracellular matrix ex: animal cell

Answer 13

a free-living, nonphotosynthetic, single-celled motile eukaryote these cells may not live in extreme environments but they can have a variety of behaviours and appearances EX: didinium is a large carnivorous protozoan (eats other cells) structure: global shape with cilia at the top and bottom and snout at the top. function: uses beating and moving cilia to swim at high speeds, and when encountering another protozoan as prey they release paralyzing darts from its snout and opens up to ingest

Answer 14

studying a few representative species to gain a deeper understanding that could be achieved if they look at many different species - lead to discoveries and benefits of human health

Answer 15

"Anything found to be true about E. coli must also be true about elephants" - small rod-shaped cell that lives in the gut of humans and other vertebrates - grows and reproduces in a simple nutrient broth in a lab 1. gene expression 2. how cells replicate their DNA and how they decode the instructions to make proteins 3. advances in biotechnology --> recombinant DNA 4. producing large quantities for therapeutic proteins - insulin = biomedicine

Answer 16

a living thing selected for intensive study as a representative of a large group of species - mouse, yeast, E.coli scientists around the world can pool their knowledge and resources to gain a deeper understanding - better to understand on than use many different species

Answer 17

"Anything found to be true of E.coli must also be true of elephants" - small, rod-shaped cells that live in the gut of the humans and other vertebrates

Answer 18

- regulate gene expression - how cells replicate their DNA to decode instructions --> proteins - advancements in biotechnology - recombinant DNA - producing large quantities of therapeutic proteins = insulin

Answer 19

small single-celled fungus rigid cell wall, usually immobile, has an array of organelles (no chloroplast) - when resources are available, it can grow a lot - carries out the basic tasks of mating with the opposite sex - allows us to study the genetics of sexual reproduction

Answer 20

false it is more closely related to animals and eukaryotes

Answer 21

understanding fundamental mechanisms in eukaryotic cells - cell division - chain of events by which the nucleus and all the other components of a cell are duplicated --> daughter cells

Answer 22

false bacteria and archaea are separated from each other by more than 3 billion years of evolution - plants, animals, fungi diverged 1.5 b years ago

Answer 23

a small weed in the cabbage family - Arabidopis thaliana = model plant - grown indoors, in large numbers, produces thousands of offspring

Answer 24

the model organism has enabled us to understand plants growing towards sunlight flowering in the spring coordinated development with the seasons - studying this simple weed (has some similar genes in agricultural species) can provide insight on the development and physiology of the crop plants that we depend on

Answer 25

we now have a detailed description of the sequence of events cells divide --> become specialized - 70% of the genes have some counterparts in humans - acts as a model for human bodies 1. understanding of apoptosis, a form of programmed cell death - the animal disposes of a surplus of cells - importance in the development of cancer

Answer 26

studying animal genetics - proof that genes which are units of heredity are carried on chromosomes - show us how the genetic instructions encoded in DNA direct the development of a fertilized egg cell or zygote into an adult multicellular organism - understanding genes that are needed to make a properly structured adult body, gut, wings, legs, and eyes - which genes are passed on directly

Answer 27

fish can be easily bred and maintained in a lab they are clear during the first 2 weeks of living, allowing us o observe how cells behave during development - development of heart and blood vessels

Answer 28

used as a model organism to help genetics, development, immunology, and cell biology - it is possible to breed mice with engineered mutations in any gene - this can be used to test the function of any gene and determine how it works in a living mammals

Answer 29

the only way to make a new cell is through a pre-existing one, a parent cell must execute an orderly sequence of rxns, duplicate its contents, divide - any complications can be devastating to the cell - because proteins are reliant on the cell division process, scientists have worked backwards to see which protein causes abnormalities

Answer 30

yeast mutants that are defective in their ability to complete cell division have led to the discovery of many genes that control the cell cycle - Cdc genes

Answer 31

paul nurse S. pombe = a type of yeast - grows by elongation and fission into 2 - found that Cdc genes called Cdc2 was required to trigger several key events in the cell division cycle - without being activated by mutation the yeast would not divide - replacing the faulty Cdc2 gene in S. pombe with a function Cdc2 should repair the defect

Answer 32

S. cerevisiae divides by forming a small bud that grows steadily until it separates from the mother cell - wanted to see if the proteins from one type of yeast substitute for those of another - they took S. cerevisiae DNA into S. pombe cells that contained a temp-sensitive mutation in the Cdc2 gene that kept the cells from dividing when the heat was turned up. - found that some of the mutant S. pombe cells regained the ability to proliferate at the elevated temp - rescued cells can divide again and again to form visible colonies of millions of yeast cells - the rescued cells had a piece of DNA from S. cerevisiae of cdc2 - the result was not that surprising because how different can one yeast be from another - they repeated the experiment with human DNA and the results where the same

Answer 33

false Paul Nurse proved this and they are identical because the proteins are almost the same and the AA is almost in the same order

Answer 34

in very different eukaryotes they have very similar amino acid sequences and can be functionally interchangeable - also seen that the cell cycle is controlled similarly in every eukaryotic organism alive today - in the experiment with yeast, the mutant yeasts were rescued and able to divide because of the introduction of a piece of human DNA, this shows that the molecular machinery for reading the information encoded in DNA must be similar from cell to cell and from organism to organism

Answer 35

in glass the experiments are being tested in a test tube or petri dish - because they are maintained in a controlled environment, they are accessible to study in ways that are not possible in vivo

Answer 36

that the experiment is happening inside the organism

Answer 37

true fibroblasts which are connective tissue cells, continue to secrete proteins in vitro

Answer 38

since the bond between H--O is polar and has a slightly negative and positive dipole, when a positive region comes close to a negative region the electrical attraction between them forms a weak bond called a hydrogen bond - noncovalent and are much weaker than covalent bonds because random thermal motions can easily break them down - N, O, F - can produce a network of hydrogen bonds - without hydrogen bonds, life could not exist - helps the molecule fold into a particular shape

Answer 39

water-loving - substances that contain polar bonds and can form hydrogen bonds also mix well with water - DNA, RNA, most proteins, phospholipid bilayer

Answer 40

water-fearing molecules - uncharged with little to no hydrogen bonds - they do not dissolve in water

Answer 41

- quite weak, their energies can sum to create an effective force between 2 molecules - does not involve the sharing of electrons - EX: hydrogen bonds, London dispersion

Answer 42

forces that draw together oppositely charged atoms - ionic bonds and the attractions between other molecules that have polar or covalent bonds - they are the strongest when the atoms are fully charged like Na+ and Cl- - when a large molecule with lots of polar functional groups comes close to another molecule with a pattern of positive and negative charges as well, they create weak forces of attraction and bind

Answer 43

a non-covalent bond when 2 atoms come close to each other, these nonspecific interactions cause an electron cloud which generate a transient attraction between the atoms - these occur in all type of molecules, even those that are nonpolar and cannot form ionic or hydrogen bonds

Answer 44

covalent ionic hydrogen van der waals

Answer 45

- tendency of nonpolar molecules or groups to cluster together in an aqueous (water) environment. These forces arise because water molecules, which are polar, prefer to interact with other polar or charged substances. Since nonpolar molecules cannot form hydrogen bonds with water, they are excluded by water molecules, resulting in the aggregation of nonpolar molecules to minimize their contact with water.

Answer 46

important part in promoting molecular interactions when building cellular membranes - constructed from lipid molecules that have long chains of nonpolar hydrocarbons since the C-H has no net positive charge, they cannot form hydrogen bonds and are pushed out the network of water molecules inside the cell

Answer 47

DNA and RNA are built from subunits called nucleotides that consist of a nitrogen ring that is clicked to a 5carbon sugar + a phosphate group - the 5carbon sugar is either ribose or deoxyribose - the nitrogen component is a base (called a base because in acidic conditions they can increase the OH conc)

Answer 48

CUT Cytosine, Uracil, Thymine single ringed - one 6ring smaller

Answer 49

GA Guanine, Adenine they are double-ringed - one 6ring fused to a 5ring) larger

Answer 50

adenosine triphosphate the transfer energy in metabolic rxns STRUCTURE - 3 phosphates linked in series by 2 phosphoanhydride bonds (breaks apart using hydrolysis)

Answer 51

hydrolysis breaks the terminal phosphate group to transfer to another molecule of release energy for biosynthetic reactions - it releases energy when it is hydrolyzed back to ADP and phosphate

Answer 52

the backbone of DNA - storage and retrieval of biological information - building blocks for the construction of nucleic acids, long polymers that have nucleotides linked together by phosphodiester bonds

Answer 53

- made from nucleotides with phosphodiester bonds - 2 different types - ribonucleic acids/RNA and deoxyribonucleic acids/DNA - RNA = A, C, G, U at the 2' position of the ribose carbon ring (U is similar to T), single-stranded = 1 polynucleotide chain, serve as more as carriers of molecular instructions - DNA = A, C, G, T, double-stranded, helix, 2 polynucleotide chains, long-term heredity info

Answer 54

the bond that attaches the sugar to the base in nucleotides placed on a certain carbon - each carbon is numbered and when attached it is called the 5-prime carbon or 5'

Answer 55

nucleoside = Base + sugar nucleotide = Base + sugar + phosphate

Answer 56

a simple fungi that has genetic information for making proteins

Answer 57

the structure of DNA was determined by James Watson and Francis Crick - the structure showed how the DNA is copied and divided - but Rosaline Franklin examined DNA using x-ray diffraction analysis to see a 3D structure - which was used by Watson and Crick - found that DNA is a double helical structure that run in opposite directions (anti parallel)

Answer 58

the phosphodiester bonds link the 5' end with the 3' end of the next nucleotide this is because the ester linkages of the sugar are one either side of the carbon ring which causes the DNA strand to have chemical polarity

Answer 59

complementary base pairing enables the base pairs to be held with hydrogen bonding and arranged in the interior of the double helix A - T C - G

Answer 60

they have different nucleotide sequences which make different complementary bases and codons which code for different proteins - different genetic code = differences physically/mentally/proteins

Answer 61

the process by which the nucleotide sequence of a gene is transcribed into the nucleotide sequence of an RNA molecule --> translated into an AA sequence for a protein Gene A --> RNA A --> Protein A

Week 1 Textbook Flashcards

(89 cards)