1
Q
Nonpolar covalent bonds
A
Equal sharing of electrons; similar electronegativity
2
Q
Polar covalent bonds
A
unequal electron sharing; difference in electronegativity
3
Q
Ionic bonds
A
electron transfer
4
Q
Hydrogen bonds
A
Weak attraction between partial charges
5
Q
-OH
A
Hydroxyl group (polar)
6
Q
C=O
A
Carbonyl group (polar)
7
Q
-COOH
A
Carboxyl group (acidic)
8
Q
-NH2
A
Amino group (basic, polar)
9
Q
-PO4^3-
A
Phosphate group (polar, acidic)
10
Q
-SH
A
Sulfhydryl group (polar)
11
Q
Polarity of water
A
Allows water to:
- Form H bonds
- Dissolve polar molecules
- Adhesion
- Cohesion
(polar=hydrophilic, nonpolar=hydrophobic)
12
Q
Properties caused by hydrogen bonding
A
- Cohesion
- Adhesion
- High specific heat (water resists temp change)
- high heat vaporization
- ice floats (H bonds spread molecules apart when frozen)
13
Q
pH scale
A
measure of H+ ion concentration
(Logarithmic- 10x per unit)
14
Q
Lower pH
A
more H+, more acidic
15
Q
Higher pH
A
fewer H+, more basic
16
Q
Acids
A
pH < 7
release H+ in solution
17
Q
Bases
A
pH > 7
accept H+ or release OH-
18
Q
Buffers
A
Resist change in pH when acids/bases added
19
Q
How buffers work
A
accepting excess H+ when solution too acidic; donate H+ when solution too basic
20
Q
Strong v. weak acids/bases
A
Strong: completely dissociate
Weak: partial dissociation
21
Q
Macromolecules and monomers
A
Proteins- amino acids
Carbohydrates- monosaccharides
Lipids- fatty acids
Nucleic acids- nucleotides
22
Q
Proteins primary-quaternary
A
Primary: sequence of amino acid (peptide bond)
Secondary: alpha helix or beta sheet (hydrogen bond)
Tertiary: 3D folding, interactions of R groups
Quaternary: multiple polypeptide chains form functional groups
23
Q
Monosaccharides in plants v. animals
A
Plants: cellulose
Animals: glycogen
24
Q
Saturated v. unsaturated fatty acids
A
Saturated: less fluid; no double bonds, straight chains
Unsaturated: more fluid; one or more double bonds, kinked
25
Prokaryotic cells
simple structure; lack membrane-enclosed nucleus; bacteria and archaea
26
Function of nucleoid (prokaryotes)
site where DNA is found
27
Function of plasma membrane (prokaryotes + eukaryotes)
Encloses cytoplasm; controls movement of substances in/out of cell; site for cell signaling
28
Function of cell wall (prokaryotes + eukaryotes)
Support and protection; eukaryotes: plant cells only
29
Function of Ribosomes (prokaryotes + eukaryotes)
polypeptide synthesis
30
Function of cytoplasm/cytosol (prokaryotes/eukaryotes)
site for metabolism/metabolic pathways
31
Function of pili (prokaryotes)
allow bacteria to attach to surfaces and each other
32
Function of flagella (prokaryotes)
allow bacteria to swim
33
Function of glycocalyx (prokaryotes)
outer gelatinous covering
34
Function of nucleus (eukaryotes)
DNA organized and expressed
35
Function of lysosomes (eukaryotes)
site where macromolecules are degraded
35
Function of nuclear envelope (eukaryotes)
double membrane enclosing nucleus
36
Function of nucleolus (eukaryotes)
site for ribosome subunit assembly
36
Function of centrosome (eukaryotes)
site where microtubules grow and centrioles are found
37
Function of nucleus (eukaryotes)
complex of protein and DNA
38
Function of mitochondria (eukaryotes)
site for ATP synthesis
39
Function of rough ER (eukaryotes)
40
Function of peroxisomes (eukaryotes)
site where harmful molecules are broken down
41
Function of smooth ER (eukaryotes)
site for detoxification and lipid synthesis
42
Function of golgi apparatus (eukaryotes)
site for modification, sorting, and secretion of lipids and proteins
43
Function of cytoskeleton (eukaryotes)
protein filaments, provide shape, aid movement
44
What is included in the endomembrane system?
nuclear envelope, ER, golgi apparatus, lysosomes, vacuoles, peroxisomes
44
Function of chloroplasts (eukaryotes)
plants only- photosynthesis
45
Function of centrol vacuole (eukaryotes)
plants only- site that provides storage; regulation of cell volume
46
Endomembrane system lipid pathway
1. Synthesized in SER
2. Sent to Golgi
3. Then to...
- Plasma memb: secretion/exocytosis
- Cell memb. insertion (memb. proteins)
46
Endomembrane system protein pathway
1. Rough ER: translation and folding of proteins
2. Transport vesicle: carries proteins to Golgi
3. Golgi: modifies, sorts, packages
4. Vesicle carries to either...
- Lysosome
- Plasma Memb: secretion (exocytosis)
- Cell memb. insertion (membrane proteins)
47
Phospholipid bilayer structure
ampipathic:
- Polar (hydrophilic) head: phosphate + glycerol
- Nonpolar (hydrophobic) tail: fatty acids
selective permiability:
- only small, nonpolar can cross
- bc of hydrophobic interior
48
Fluid mosaic model
- includes phospholipids, cholesterol, membrane proteins, + carbohydrates
- lateral movement of phospholipids (fast)
49
Cholesterol function in fluid mosaic model
fluidity buffer:
- High temp: decreases fluidity
- Low temp: increases fluidity
50
Passive transport (+ types)
high concentration --> low concentration
- Simple diffusion
- Facilitated diffusion: transport protein used
51
Active transport (+ types)
low concentration --> high concentration
- Primary AT: uses pump- transports solute against conc. gradient
- Secondary AT: pre-existing gradient drives AT of another solute
52
Example of primary active transport
Na+/K+ pump (3 Na+ out, 2 K in, ATP used)
53
Osmosis
movement of water across membrane to balance solute concentrations
54
Uniporters, symporters, and antiporters
- Uniporters: bind single ion/molecule and transport it across membrane
- Symporters: bind 2+ ions/molecules and transport in same direction
- Antiporters: bind 2+ ions/molecules and transport in opposite direction
55
Aquaporins
allow rapid movement of water across the membrane
56
Anchoring junctions
hold adjacent cells together (using cadherins), attach cells to extracellular matrix (using integrins)
57
Tight junctions
prevent leakage; uses occludin and claudin
58
Gap junctions
channels (aka connexons) permit direct passage of ions and small molecules between cytosols of adjacent cells
59
Enzymes
proteins that speed up rate of chemical reactions by lowering activation energy (not by lowering delta G!!)
60
Enzyme induced fit
recognize substrates with high specifity; conformational change causes substrate to bind more tightly
61
Enzyme competitive inhibitors vs. noncompetitive inhibitors
- Competitive inhibitors: molecules that bind noncovalently to active site of enzyme + inhibit ability of substrate to bind
- Noncompetitive inhibitors: binds noncovalently to enzyme outside active site (in allosteric site) + inhibits enzyme's function
62
ΔG, H, and S
ΔG= change in free energy
H= enthalpy (usable energy)
S= entropy (unusable energy)
63
Exergonic reations
ΔG < 0
- less free energy than reactants
- spontaneous
64
Endergonic reactions
ΔG > 0
- requires addition of free energy
- not spontaneous`
65
Catabolism
break down large molecules into smaller ones; recycles organic molecules
66
Anabolism
requires energy input; synthesize larger molecules and macromolecules
67
ATP cycling
- cells constantly recycle ATP to sustain life processes
- energy comes from catabolism --> breakdown of glucose, fats, protein
68
Kinetic energy
associated with movement
69
Potential energy
Stored energy
70
Overall equation for photosynthesis
6CO2 + 6H20 + light -->C6H12O6 + 6O2
71
Linear electron flow
electrons from PSII follow pathway along ETC in thylakoid membrane, pathway generates H+ electrochemical gradient that is used to make ATP. Light energy striking PSI boosts electrons to very high level, resulting in synthesis of NADPH
72
Cyclic photophosphorylation
electrons are activated is PSI and flow through ETC back to PSI- produced H+ electrochemical gradient used to make ATP
73
ATP synthase
site for ATP synthesis- flow of H+ from thylakoid lumen into stroma (in chloroplasts)
74
Calvin cycle
1. Carbon fixation: CO2 incorporated via RuBisCo
2. Reduction + carbohydrate production: ATP used for energy, NADPH donates high-energy electrons
3. Regeneration of RuBP: 2 G3P used to make glucose and other sugars, remaining 10 needed to regenerate RuBP via several enzymes. ATP required for regen
75
Chloroplast structure
Contain chlorophyll, outer membrane, intermembrane space, inner membrane, stroma, granum, thylakoid, thylakoid lumen
76
Absorption spectrum
graph showing pigment's ligh absorption as a function of light's wavelength
77
Pigments
molecules that absorb light energy
- chlorophyll a & b: green
- carotenoids: yellow --> red
78
C3 pathway
C3 plants incorporate CO2 into RuBP to make 3PG
79
C4 pathway
limits photorespiration- enzyme PEP carboxylase functions to maintain high CO2 concentrations in bundle-sheath cells (high CO2 conc. minimizes photorespiration)
80
CAM plants
prevent photorespiration by fixing CO2 at night, running calvin cycle during day with stomata closed to reduce water loss
81
Photorespiration
- O2 level high, CO2 level low (happens in dry/hot conditions)
- inefficient: reverses incorporation of CO2 into organic molecules
82
Cellular respiration equation
C6H12O6 + 6O2 --> 6CO2 + 6H2O
83
Glycolysis
occurs in cytosol; glucose metabolism produces 2 molecules of pyruvate
1. Energy investment phase
2. Cleavage phase
3. Energy liberation phase
84
Net yield of glycolysis
Total: 4 ATP, 2 NADH
Net: 2 ATP, 2 NADH
85
Pyruvate oxidation
pyruvate broken down to CO2 and an acetyl group that becomes attached to CoA (acetyl-CoA). NADH made during process
86
Oxidative phosphorylation
1. ETC oxidized NADH or FADH2 + generates H+ electrochemical gradient
2. gradient used by ATP synthase to make ATP via chemiosmosis
87
ATP synthase
rotary machine triggered when H+ passes from intermembrane space to mitochondrial matrix by moving through membrane embedded portion of ATP synthase. Causes gamma subunit to spin, resulting in 3 conformational changes in beta subunits that promote ATP synthesis
88
Anaerobic respiration
occurs in absense of oxygen; some microorganisms carry it out by using final electron acceptor of ETC a substance other than Oxygen
89
Fermentation
organic molecules metabolized without any net oxidation (net removal of electrons)
90
Examples of fermentation
lactic acid production in muscle cells, ethanol production in yeast cells
91
Role of NADPH
used in photosynthesis (Calvin cycle); provides high-energy electrons for carbon fixation; turns CO2 into sugars
92
Role of NADH
carries high-energy electrons to ETC in cellular respiration; used to generate ATP through oxidative phosphorylation
93
What happens when NADH donates electrons to ETC?
electrons --> etc --> proton gradient --> ATP synthase makes ATP
94
Why does FADH2 make less ATP?
Because it enters the ETC at complex II, skipping the first pump
95
What gets oxidized and what gets reduced during respiration?
Glucose- oxidized; NAD+/FAD- reduced
96
Why does ETC stop if NADH stops?
No electron flow --> no proton gradient --> no ATP synthesis
97
DNA structure
- composed of nucleotides (phosphate, sugar, nitrogenous base) covalently linked to form DNA strands (antiparallel)
- 2 DNA strands held by Hydrogen bonds between bases creates double helix
98
DNA replication steps
1. Initiation- helicase unzips, topoisomerase relieves twisting ahead of fork, SSBP keeps strands separated, primase lays down primer
2. Enlongation- DNA Pol III ads new nucleotides to 3' end of growing strand, DNA Pol I removes RNA primers and replaces with DNA, ligase seals the gaps between okazaki fragments
3. Termination- forks meet, proofreed, telomerase (if needed)
99
Leading strand v. lagging strand
Leading strand- made continuously in same direction as fork
Lagging strand- made in opposite direction in okazaki fragments
100
Semiconservative DNA replication
products are 2 DNA molecules with one parental strand and one daughter strand
101
Transcription steps
1. Initiation- RNA Polymerase attaches to DNA at promoter and unwinds (eukaryotes- initiation/transcription factors)
2. Enlongation- Ribonucleoside Triphosphates line up opposite of template strand, RNA Polymerase connects 5'-->3'
3. Termination- RNA Polymerase reaches terminator, stops, releases pre-RNA
102
Splicing
mRNA processing; removes introns, exons joined by splicosome; forms mature mRNA
103
Template strand in transcription
used to make mRNA; determined by promoter direction
104
Codons
64; each specify specific amino acid or stop/start (met)
105
Translation steps
1. Initiation- mRNA assembles with ribosomal subunits and initiator tRNA molecule (carries MET(start codon))
2. Enlongation- amino acids are added to growing polypeptide chain
3. Termination- binding of release factor to stop codon; causes release of completed polypeptide from tRNA and disassembly of mRNA, ribosomal subunits, and release factor
106
Silent mutations
causes no change
107
Missense mutations
changes one amino acid
108
Nonsense mutation
changes a normal codon to a stop codon
109
Frameshift mutations
addition of a base; produces different amino acid sequence
110
Receptor types
Enzyme-linked receptors (catalytic functions), GPCR, ligand-gated ion channels
111
Role of second messengers
ex. cAMP; amplify signal and increase speed of signaling pathways
112
Adenylyl cyclase pathway key second messenger, main effector enzyme, and main kinase activated (GPCR)
- cAMP
- Adenylyl Cyclase
- PKA
113
Phospholipase C pathway key second messengers, main effector enzyme, and main kinase activated (GPCR)
- IP3, DAG, Ca+
- Phospholipase C
- PKC
114
-CH3
methyl group (nonpolar)
BIOL 224
flashcards
Decks in class (13)
# Cards
-
Ch. 4- General Features of Cells52
-
Ch. 5- Membrane Structure, Synthesis, & Transport & 10.2- Cell Junctions45
-
Ch. 6- Intro to Energy, Enzymes, and Metabolism26
-
Ch. 8- Photosynthesis46
-
Ch. 7- Cellular Respiration55
-
Ch. 9- Cell Communication33
-
Ch. 11- Nucleic Acid Structure, DNA Replication, and Chromosome Structure43
-
Ch. 12- Gene Expression at the Molecular Level35
-
Ch. 15- DNA Mutations13
-
Ch. 16- The Eukaryotic Cell Cycle, Mitosis and Meiosis52
-
Ch. 17- Simple Patterns of Inheritance28
-
Ch. 22- Evolution31
-
Final118
