biology Flashcards
(97 cards)
1
Q
Matter
A
all the stuff around us
-substance that takes up space and has mass
Composed of:
-elements
2
Q
Atom
A
smallest unit of matter
3
Q
Molecule
A
when two or more atoms join together
4
Q
Ribose
A
5 carbon sugar (CH2O)n where n=5
5
Q
Fructose
A
6 carbon sugar (CH2On where n=6 and is an isomer of glucose
6
Q
Glucose
A
6 carbon sugar (CH2O)N where n=6 and is an isomer of fructose
7
Q
Dissacharides
A
2 monomers come together via dehydration rxn or condensation rxn
8
Q
What connects carbohydrates together?
A
glycosidic bond
9
Q
Sucrose
A
dissacharide
-1 glucose and 1 fructose
10
Q
Lactose
A
dissacharide
-1 galactose and 1 glucose
11
Q
Maltose
A
dissacharide
-2 glucose monomers linked togehter
12
Q
Starch
A
Polysaccharide
- storage in plants
- glucose monomers linear and branched
13
Q
Amylose
A
linear plant starch
-a-1,4 glycosidic bonds
14
Q
Amylopectin
A
branched form of plant starch
-a-1,6 glycosidic bonds
15
Q
Glycogen
A
Polysaccharide found in humans
- storage of glucose in humans
- more branching than in starch (amylopectin)
16
Q
Cellulose
A
Structural polysaccharide in plant cell walls
- glucose polymer
- B-1,4 glycosidic bonds
17
Q
Polypeptide
A
Polymers of amino acids connected by peptide bonds
-form via dehydration rxn to make peptide bonds
18
Q
Secondary structure of protein
A
intermolecular interactions between atoms of poleypetid backbone
- does not involve R groups
- Hydrogen bonding N-H
Most commne secondary proteins:
b-pleated sheets
-alpha helices
19
Q
Tertiary Structure
A
interaction between R groups at various Aino acids:
-interactions includse: ioninc bonding, hydrogen bonding, dipole dipole interactions and London dispersions
20
Q
What can denature proteins?
A
excess temperature
chemicals
pH changes
radiation
21
Q
Protein Function
A
1) Storage
- reserve of amino acids
2) Hormones
- signaling molecules that circulate through the body to regulate physiological processes
3) Motion
- Movement generation for individual cells or entire organism
4) Structure
- provide strength and support to tissues
5) Immunity
- prevention and protection against foreign invaders
6) Enzymes
22
Q
Enzymes
A
biological, globular (usually) protein catalysts that speed up specific forward and reverse reactions by lowering activation energies
23
Q
Enzymes specificity constant
A
measures how efficient an enzyme is converting a substrate to product
-High specificity constant=High substrate affinity=highly efficient enzyme
24
Q
Ribozyme
A
RNA molecule capable of acting like an enzyme
25
Cofactors
nonprotein molecules
| -assist enzymes in the reaction they manipulate
26
Coenzymes
Organic Coenzymes
-ex: vitamins
Inorganic Coenzymes
-metal ions such as Fe2+ or Mg2+
27
Holoenzymes
enzymes that are bound to their cofactor
28
Apoenzyme
enzyme not bound to cofactor
29
Competitive inhibition
inhibitors compete with substrates for active sites on enzymes
-increase substrate; higher chance substrate binds to active site(outcompete)
Km Increases
-Vmax remains the same
30
Noncompetitive inhibition
Inhibitors bind to allosteric site of enzymes
-modifies active site so that the substrate has reducing binding or can't bind to active site at all
Km remains the same
Vmax Decreeases
31
Velocity (V) or reaction
| -definition
rate at which the reaction is occuring
32
Vmax
| -definition
Maximum velocity the reaction can go
33
Michaelis Constant (Km)
the susbtrate concentration at which the velocity is 50% of the Vmax
- small Km=high binding affinity, only need a little bit of substrate
- large Km=low binding affinity, need a lot of substrate
34
Polypeptides
polymers of amino acids
35
Lipids
Hydrophobic, non polar molecules
| -long hydrocarbon chain
36
Lipids function
1) Store energy
2) Provide insulation
3) contribute to cell membranes
4) synthesis of critical hormones
37
Triacylglycerol/triacylglyceride
```
Lipid Molecule: Fat
-found in cells call adipocytes
composed of:
glycerol backbone
-3 FAtty acid tails
```
38
Phospholipids
```
found in cell membranes
LIPID MOLECULE
Composed of:
-glycerol backbone
-one phosphate group (Polar head group)
-2 FA's
```
AMPHipathic molecule-contain hydrophobic and hydrophilic molecules
39
Amphipathic
contain hydrophobic and hydrophilic regions
40
Glycolipids
```
Found in cell membranes
LIPID MOLECULE
Composed of:
glycerol backbone
-carbohydrate (polar head grouP)
-2FA's
```
41
Cholesterol
LIPID MOlecule
- make up 30-40% of eukaryotic cell membrane
- amphipathic
- 4 hydrocarbon rings=steroid nucleus
Liver makes cholesterol and also comes from our diet
42
What factors influence the fluidity of a membrane
1) temperature
2) cholesterol
3) degrees of unsaturation
Cold:
increases FA unsaturation
43
Function of cholesterol
1) Membrane fluidity
2) precursor for Vit D, Bile Acids,
3) Steroid Precursor
- testosterone and estrogen (sex hormones)
44
Why is RNA more reactive than DNA
RNA is more reactive (less stable) due to its 2'OH
45
Which nitrogenous bases bind to each other in DNA vs RNA and how many bonds between
DNA
A=T 2 H bonds
G-C 3 H bonds
RNA
A=U 2 H bonds
G-C 3 H bonds
46
Cell Theory
1) All life is composed of one or more cells
2) The cell is the basic structural, functional, and organizational unit of life
3) All cells come from preexisting cells via cell division
4) Division allows the genetic information within the cell to be passed onto new cells
5) organisms activity is dependent on the activity of its independent cells
6) Metabolism and biochemistry (energy Flow) occurs within the cells
7) All cells have the same chemical composition
**DOES NOT APPPLY TO VIRUSES BC THEY ARE NOT Living cells
47
Prions
misfolded proteins that cause other proteins to misfold
| -destroy function
48
Cell Membrane
composed of:
1) Phospholipids
2) Cholesterol
3) Proteins
49
Membrane Proteins
| Cell membrane
2 types:
1) Integral Proteins (Transmembrane proteins)
- extend through the entire phospholipid bilayr
- amphipathic
- Receptor proteins
2) Peripheral membrane Protein
- on the periphery
- hydrophilic
- can be attached to to the hydrophilic surface of integral membanre proteins or partially inserted into the membrane
50
Peripheral Membrane function
1) Adhesion Proteins
- attach adjacent cells to other things Iike other cells
- act as anchors for the cytoskeleton
2) Cellular regonition proteins:
- help cells recognize each other
- interact with receptor proteins
51
Simple Diffusion
- Flow of substances down their concentration gradient (High to Low concentration)
- usually small uncharged nonpolar particles such as Oxygen and CO2
- Does not require energy/consume energy
Osomosis a type of simple diffusion
52
Facilitated Transport
How large, hydrophilic molecules travel across the phospholipid bilayer through integral proteins
Can be:
- uniport-one molecule moving in one direction
- symport- several molecules moving in one direction
- antiport- several molecules moving in opposite direction
53
2 main types of integral proteins involved in facilitated transport
Channel Proteins
- Tunnels that face extracellular and intracellular environments
- small polar molecules and ions
Carrier proteins:
- change shape to facilitate movement of molecules through the protein
- only face one side at a time
54
Passive Diffusion
Type of Facliitate transport
- particles down their concentration gradient (high to low concentration)
- does not require eneergy
- relies on channel proteins (Tunnels)
55
Porins
example of channel proteins used in passive diffusion
56
Active Transport
particles travel against their concentration gradient (low to high concentration)
- require energy input
- energy source dictates if it will be primary or secondary active transport
- rely on carrier proteins that change their shape
57
Primary Active Transport
-used the energy released from ATP hydrolysis to pump molecules against their concentration gradient
Ex: Na+/K+ pump because it hydrloyzes ATP
58
Na+/K+ pump
exchanges:
-3 Na+ out and 2 K+ in; both go against concentration gradient by primary active transport
Pump consumes one ATP molecule
-ATP hydrolysis powers pump
-pump also an ATPase(ATP hydrolysis enzyme)
59
Secondary Active Transport
uses energy obtained form a source other than ATP
- usually free energy released by molecules traveling down their concentariotn gradient
* *relies on primary active transport to create concentration gradient
60
Cytosis
processes the cells use to facilitate bulk transport of large, hydrophilic/polar molecules
```
2 main types:
-Endocytosis
-exocytosis
both require energy
-both are active transport mechanism
```
61
Endocytosis
cell membrane forms a plasma membrane bound package (vacuole or vesicle) around something the extracellular matrix wants to internalize
-transports molecules into the cell
62
Phagocytosis
type of endocytosis
- cell engulfs undissolved materials
- known as cellular eating
63
Pinocytosis
type of endocytosis: similar to phagocytosis
- known as cellular drinking
- cell will pinch inward (INVAGINATE) so that it engulfs dissolved materials (liquids)
64
Exocytosis
when material exit the cell
| -essential part of the vesicle secretion from the Golgi apparatus
65
Nucleus
In eukaryotic cells
- house and protect DNA
- DNA replication and Transcription occur inside the nucleus
66
Nuclear envelope
nucleus membrane
- set of 2 phospholipid bilayers (one inner and one outer)
- inbetween two bilayers=perinuclear space
67
Nucleoplasm
Aqueous medium in the nucleus
| -DNA is floating in this
68
Nuclear pores
Holes In the nuclear envelope allowing for molecules to travel in and out
69
nuclear lamina
associated with the inner membrane of nuclear envelope
- Provides structural support to the nucleus
- regulates DNA organization, DNA replication, and Cell division
70
Nucleolus
dense regions within the nucleus
- where rRNA is produced
- site of ribosomal subunits production
71
Ribosomal subunits
contain rRNA and protein
| composed in the nucleolus
72
Ribosomes
function in protein translation
- do not contain a membrane
- NOT organelles
- both eukaryotes and prokaryotes contain ribosomes
Float freely in the cytosol or attached to the RER
73
Eukaryotic Ribosomes
2 subunits:
60S subunit
40S subunit
come together to form the 80S eukaryotic ribosome*
-each subunit produced in the nucleoplasm and come together in the cytosol of the cell
74
RER
ribosomes attach to the cytoplasmic side and translate proteins in the lumen
- undergo modifications
- ex: glycolsylation attaches a carbohydrate to protein then the glycoprotein heads to the Golgi apparatus
75
role of the SER
synthesize lipids (fats), steroid hormones, detoxify cells
76
Golgi apparatus
Products enter golgi and undergo modifications such as phosphorylation
77
cytoskeleton
lies within the cytoplasm of both eukaryotic and prokaryotic cells
contains:
microfilaments
-intermediate filaments
-microtubules
78
Microfilaments
smallest diameter
- contain a double helix of 2 actin filaments
- crucial role in cell movement
79
Intermediate filament
middle diameter of the 3
- contain many different types of proteins
- EX: keratin-skin hair and nails
- primary role cellular structural support
80
Microtulbules
Provide structural integrity
- hollow tube, walls made up of tubular protein dimers
- partake in cell division and production of cilia and flagella
81
Tight Junctions
proteins juctnios that provide water tight seal b/w cells
-insure that materials must enter the cell to pass through the tissue
Ex; cell linings and digestive tract
82
Desmosomes
STAPLES that hole adjacent cells together
| -provide mechanical stability and present in tissues subject to mechanical stress
83
Anchor juctions
Desmosomes and adhering suctions type of anchor juctnios
84
Gap junctions
allow for passage of small ions and small molecules between cells
-ie heart
85
Osmosis
simple diffusion mechanism (no energy and does not utilize channel proteins)
-water travels across a semipermeable membrane from areas of LOW TO HIGH SOLUTE CONCENTRATION (high to low water concentration)
86
Isotonic Solutions
extracellular and intracellular enviroments have the same solute concentration
-animal cells prefer
87
Hypertonic SOlution
solute concentration outside the cell is high
- water will leave the cell via osmosis to attempt to lower solute concentration
- LOSS OF FLUID causes the cell to shrivel
Cells in this solution undergo PLASMOLYSIS(shrinkage of cytoplasm from water loss away from cell wall)
88
Hypotonic Solution
If the solute concentration is lower outside the cell than inside the cell
- water from external environment will travel into cell
- animal cell will swell and eventually burst in a process called Cell lysis
89
Exergonic Reactions
release energy
90
Endergonic reactions
require energy
91
ATP
- unstable RNA nucleoside triphosphate
- ATP =hydrolysis reactions are exergonic (release energy) and spontaneous
- reaction coupling links unfavorable reactions with favorable ones
92
Mitochondria
powerhouse of the cell
| -make ATP through cellular respiration (Catabolic process)
93
Endosymbioitic theory
aerobic bacteria were internalized as mitochondria whale photosynthetic bacteria became chloroplasts
-evidence=size similarities and mitochondria and chloroplast contain their own circular DNA and ribosomes
94
Glycolysis
converts 6C glucose into 3C pyruvate
- only pathway in aerobic glycolysis that does not require oxygen=aneorobic process
- occurs within the cytosol of the cell
- STEPs 1-5=energy investment phase
- STeps 6-10=energy payoff phase
4 ATP produced, 2 ATP invested= 2ATP net gain
95
Oxidation of Pyruvate in Mitochondria
1) Carboxyl group is removed from Pyruvate releasing CO2
2) NAD+ is reduced to NADH
3) acetyl group is transferred to coenzyme A=Acetyl CoA
Enzyme: Pyruvate Dehydrogenase complex
96
Krebs cycle: where does it occur in eukaryotes vs prokaryotes?
Eukarhotes=Mitochonrial matrix
| Prokaryotes=Cytosol
97
What does the Krebs cycle produce?
2 CO2
3NADH
1FADH2
1 GTP
