Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Peeb MCAT > Biochem Quicksheets > Flashcards

Biochem Quicksheets Flashcards

Most important Biochem concepts

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards
1
Q

Amino acids have what chirality

A

L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Amino acids have what configuration

A

S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the nonpolar, nonaromatic amino acids

A

GAVLIPM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the positively charged amino acids

A

HRK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the negatively charged amino acids

A

DE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the polar amino acids

A

STNCQ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the aromatic side chains

A

FWY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Peptide bond formation is what reaction

A

Condensation (dehydration) - Nucleophilic amino group attacks the carbonyl C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Primary structure

A

linear sequence of AAs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Secondary structure

A

local structure, stabilized by H bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

a helices and b bleated sheets are an example of what degree of structure?

A

secondary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Tertiary structure

A

3D structure stabilized by hydrophobic interactions, H bonds, acid-base (salt bridges), and disulfide bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

disulfide bonds are made of what AAs

A

cysteines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Quaternary structure

A

interactions b/w subunits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What can cause denaturation of structure?

A

heat and solutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what do enzymes do?

A

lower activation energy and change rate at which equilibrium is reached

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what do enzymes NOT do?

A

alter free energy (G) or enthalpy (H)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Ligase

A

joins 2 large biomolecules (usually same type)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Isomerase

A

catalyze interconversion of isomers (ex constitutional and stereoisomers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Lyases

A

catalyze cleavage without the addition of water or transfer of e- (*synthesis is the reverses rxn and is more important)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hydrolases

A

catalyze cleavage with the addition of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Oxidoreductases

A

catalyze redox rxns that involve transfer of e-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Transferases

A

move FG from 1 molecule to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Saturation kinetics

A

as [s] increases, rxn rate increases until reaches a max

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

At 1/2 Vmax, [s] =

A

Km

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Michaelis-Mentin equation

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Competitive inhibitor effects

  1. Binds to:
  2. Impact on Km?
  3. Impact on Vmax
A
  1. active site
  2. increases
  3. no change
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Noncompetitive Inhibitor effects

  1. Binds to
  2. Impact on Km
  3. Impact on Vmax
A
  1. Allosteric site (E or ES)
  2. No change
  3. Decreases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Uncompetitive Inhibitor

  1. Binding site
  2. Impact on Km
  3. Impact on Vmax
A
  1. ES complex
  2. Decreases
  3. Decreases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

5 structural proteins

A

collagen, elastin, keratin, actin, tubulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Motor proteins (3)

A

capable of force generation through a conformation change

(myosin, kinesin, dynein)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Binding proteins

A

bind a specfic substrate, either to sequester it in the body or hold its concentration at steady state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

CAM

A

cell adhesion molecule - binds cells to other cells or surfaces

(cadherins, integrins, selectins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Antibodies (Ig)

A

Immunoglobulins - target a specific antigen on a pathogen or toxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Ion channels

3 types

A

used for regulating ion flow into/out of cell

ungated, voltage-gated, ligand gated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Enzyme linked receptors

A

participate in cell signaling thru extracellular ligand binding and initiation of second messenger cascades

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

GPCR

A

G protein coupled receptor - membrane-bound protein associated with a trimeric G-protein (initiate 2nd messenger systems)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Cooperative Enzymes show what kind of curve

A

sigmoidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

trioses

tetroses

A

3-carbon sugars

4-carbon sugars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

aldoses

ketoses

A

sugars with aldehydes as their most oxidizedgroup

sugars with ketones as their most oxidized group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

D-sugars

A

-OH (highest # chiral carbon) on the right

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

L-sugars

A

-OH on the left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Diastereomers

A

differ at at least 1 but not all chiral carbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

2 kinds of diastereomers

A

epimers - differ at 1 chiral carbon

Anomer - differ at the anomeric carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

anomeric carbon

A

new chiral center formed in ring closure, carbon containing the carbonyl in straight-chain form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

alpha and beta anomers

A

alpha - trans to -CH2OH (below ring)

Beta - cis to CH2OH (above ring)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

mutarotation

A

one anomeric form shifts to another, with the straight-chain form as an intermediate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

4 monosaccharides

A

D-fructose, D-glucose, D-galactose, D-mannose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

D-fructose

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

D-glucose

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

D-galactose

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

D-mannose

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

carbohydrates undergo what 3 types of rxns?

A

oxidation-reduction, esterification, glycoside formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

esterification

A

a reaction of an alcohol with an acid to produce an ester and water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

glycoside formation

A

basis for building complex carbs and requires anomeric carbon to link to another sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

deoxy sugar

A

replace -H with -OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Common disaccharides

A
  1. sucrose (glucose-a-1,2-fructose)
  2. lactose (galactose-b-1,4-glucose)
  3. maltose (glucose-a-1,4-glucose)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

3 polysaccharides to know

A

cellulose - main structural component of plant cell walls, main source of fiber for human diet

starches (amylose and amylopectin) - main energy storage forms for plants

glycogen - a major energy storage form for animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

nucleoside

A

five carbon sugar + nitrogenous base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

nucleotide

A

nucleoside + 1-3 phosphate groups (ex. ATP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Nucleotides in DNA contain what sugar?

Nucleotides in RNA contain what sugar?

A

deoxyribose

ribose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

DNA reads in what direction?

What is the polarity?

What is the structure?

A

5’-3’

antiparallel

double helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

In RNA, A pairs with ___ via # hydrogen bonds

A

U, 2

64
Q

Nucleosomes are made of

A

(H2A, H2B, H3, H4)x2 histones with DNA wrapped around. stabilized by H1

65
Q

Telomeres

A

ends of chromosomes, high G-C content to prevent DNA unraveling

66
Q

Centromeres

A

hold sister chromatids together until they are separated during anaphase in mitosis, high G-C content

67
Q

DNA replication in prokaryotes

  1. # origins of replication
  2. unwind of DNA helix with?
  3. Stabilization of unwound template strands with?
  4. Synthesis of RNA primers with?
  5. Synthesis of DNA with?
  6. Removal of RNA primers with?
  7. Replacement of RNA with DNA by?
  8. Joining of Okazaki fragments by?
  9. Removal of positive supercoils ahead of advancing replication forks by?
  10. Sythesis of telomeres
A
  1. one per chromosome
  2. Helicase
  3. ssDNA binding protein
  4. Primase
  5. DNA pol III
  6. DNA pol 1 (5’-3’ exonuclease)
  7. DNA pol I
  8. DNA ligase
  9. DNA topoisomerases (DNA gyrase)
  10. not applicable
68
Q

DNA replication in eukaryotes

  1. # origins of replication
  2. unwind of DNA helix with?
  3. Stabilization of unwound template strands with?
  4. Synthesis of RNA primers with?
  5. Synthesis of DNA with?
  6. Removal of RNA primers with?
  7. Replacement of RNA with DNA by?
  8. Joining of Okazaki fragments by?
  9. Removal of positive supercoils ahead of advancing replication forks by?
  10. Sythesis of telomeres
A
  1. multiple per chromosome
  2. Helicase
  3. ssDNA-binding protein
  4. Primase
  5. DNA pol alpha, delta, epsilon
  6. RNase H (5’-3’ exonuclease)
  7. DNA pol delta
  8. DNA ligase
  9. DNA topoisomerases
  10. Telomerase
69
Q

In what direction does DNA polymerase read? In what direction is DNA synthesized?

A

read 3’-5’, synthesized 5’-3’

70
Q

leading strand

A

1 primer and can be synthesized continuously

71
Q

lagging strand

A

many primers, synthesized in okazaki fragments

72
Q

Recombinant DNA

A

dna composed of nucleotides from 2 diff sources

73
Q

DNA cloning

A

introduces fragment of DNA into vector plasmid

74
Q

restriction enzyme

A

restriction endonuclease - cuts both the plasmid and the fragment, leaving them with sticky ends, which can bind

75
Q

DNA library

A

large collections of known DNA sequences

76
Q

Genomic libraries

A

contain large fragments of DNA (coding and noncoding regions) CAN’T be used to make recombinant proteins or for gene therapy

77
Q

cDNA libraries (expression libraries)

A

contain smaller fragments of DNA (only include exons of genes expressed) CAN be used to make recombinant proteins or for gene therapy

78
Q

Hybridization

A

joining of complementary base pair sequences

79
Q

PCR

A

polymerase chain reaction - automated process to make millions of copies of a DNA sequencefrom a small sample by hybridization

80
Q

agarose gel electrophoresis

A

separate DNA molecules by size

81
Q

Southern blotting

A

to detect presence and quantity of various DNA strands in a sample. After electrophoresis, sample is transferred to a membrane that can be probed with single-stranded DNA molecules to look for a sequence of interest

82
Q

DNA sequencing

A

uses dideoxynucleotides to terminate DNA chain cuz they lack a 3’OH group

83
Q

Central Dogma

A

DNA-RNA-proteins

84
Q

Degenerate code

A

allows multiple codons to encode the same amino acid

85
Q

Initiation codon

A

AUG (methionine)

86
Q

Termination codons

A

UAA, UGA, UAG

87
Q

wobble

A

3rd base in the codon can be different and won’t affect protein

88
Q

4 types of point mutations

A

silent - no effect

nonsense (truncation) - premature stop codon

missense - codes for diff AA

Frameshift - nt add/deleted and changes reading frame

89
Q

RNA differences from DNA (3)

A

ribose sugar, Uracil instead of Thymine, single-stranded

90
Q

3 major types of RNA

A

mRNA, tRNA, rRNA

91
Q

messenger RNA

A

carries message from DNA in the nucleus via transcription of the gene, travels into the cytoplasm to be translated

92
Q

transfer RNA

A

brings in AA, recognizes the codon on the mRNA using its anticodon

93
Q

ribosomal RNA

A

makes up much of the ribosome, enzymatically active

94
Q

Describe the very basic steps of transcription

A
  1. helicase and topoisomerase unwind DNA double helix
  2. RNA pol II binds to TATA box in the promoter region
  3. hnRNA synthesized from DNA template (antisense strand)
95
Q

Describe the basic post-transcriptional modifications

A
  1. 7-methylguanylate triphosphate cap added to 5’ end
  2. polyadenosyl tail added to 3’ end
  3. splicing done by spliceosome, introns removed and exons ligated together
96
Q

alternative splicing

A

combines different exons to acquire different gene products

97
Q

where does translation occur

A

at the ribosome

98
Q

what are the 3 stages of translation

A

initiation - The ribosome assembles around the target mRNA. The first tRNA is attached at the start codon

elongation - tRNA transfers an amino acid to the tRNA corresponding to the next codon. The ribosome then moves (translocates) to the next mRNA codon to continue the process, creating an amino acid chain.

termination - When a stop codon is reached, the ribosome folds the polypeptide into it’s final structure.

99
Q

Describe the post-translation modifications

A
  1. folded by chaperones
  2. formation of quaternary structure
  3. cleavage of proteins or signal sequences
  4. covalent addition of other biomolecules (phosphorylation, carboxylation, glycosylation, prenylation)
100
Q

operons (what model)

A

Jacob-Monod model - inducible or repressible clusters of genes transcribed as a single mRNA

101
Q

transcription factors

A

search for promoter and enhancer regions in the DNA

102
Q

promoters and enhancers

A

promoter - within 25 bp of the transcription start site

enhancer - more than 25 bp away from the transcription start site

103
Q

osmotic pressure (and equation)

A

pressure applied to a pure solvent to prevent osmosis, related to the conc of the solution

π = iMRT

i = Von’t Hoff factor - # ions in solution

M - conc in mol/L

R - 0.08206 L atm mol-1 K-1

T - temp in K

104
Q

Passive transport

3 types

A

does not require ATP cuz the molecule is moving down its conc gradient from high to low

  1. simple diffusion - no transporter, small, nonpolar molecules move
  2. osmosis - diffusion of water across semipermeable membrane
  3. facilitated diffusion - use transport proteins
105
Q

active transport (primary and secondary)

A

primary - requires energy ATP

secondary - use ion gradient (antiport or symport)

106
Q

pinocytosis

phagocytosis

A

cell drinking

cell eating

107
Q

Need to memorize glycolysis! But what are the 7 enzymes that are important?

A

glucokinase, hexokinase, PFK-1, PFK-2, Glyceraldehyde -3-phosphate dehydrogenase, 3-phosphoglycerate kinase and pyruvate kinase

108
Q

glucokinase

A

present in the pancreatic beta-islet cells as a glucose sensor and is responsive to insulin in the liver

109
Q

hexokinase

A

traps glucose

110
Q

PFK-1

A

rate-limiting step of glycolysis

111
Q

PFK-2

A

produces fructose-2,6-bisphosphate to activate PFK-1

112
Q

glyceraldehyde-3-phosphate dehydrogenase

A

produces NADH

113
Q

3-phosphoglycerate kinase and pyruvate kinase

A

substrate-level phosphorylation (add phosphate group to ADP or GDP to make ATP or GTP)

114
Q

3 enzymes of irreversible rxns

A

glucokinase/hexokinase, PFK-1, pyruvate kinase

115
Q

what happens to NADH produced in glycolysis aerobically and anaerobically

A

aero - oxidized by mitochondrial ETC

anaero-oxidized by lactate dehydrogenase

116
Q

pyruvate dehydrogenase

A

converts pyruvate to acetyl-CoA. stimulated by insulin and inhibited by acetyl-CoA

117
Q

Need to memorize Citric Acid Cycle! What is the main purpose of it? and where does it occur

A

oxidize acetyl-CoA to CO2 and generate NADH and FADH (electron carriers) and GTP

in mitochondrial matrix

118
Q

Need to memorize ETC! Where does it take place?

A

matrix-facing surface of the inner mitochondrial membrane

119
Q

ETC

A

NADH donates electrons and passed down complexes, reduction potentials INCREASE and end on Oxygen (highest reduction potential)

120
Q

Can NADH get across mitochondrial membrane? Mechanisms?

A

HECK NO, uses shuttles

  1. glycerol 3-phosphate shuttle
  2. malate-aspartate shuttle
121
Q

proton motive force

A

electrochemical gradient generated by the ETC across the inner mitochondrial membrane

inner mitochondrial membrane has higher proton conc than matrix

122
Q

chemiosmotic coupling

A

form ATP as protons create gradient passing thru ETC

123
Q

ATP synthase

A

enzyme responsible for generating ATP from ADP and an inorganic phosphate Pi

124
Q

Energy yield of glycolysis

A

2 NADH and 2 ATP

125
Q

energy yield of pyruvate dehydrogenase

A

1 NADH (2 NADH per molecule of glucose cuz 2 pyruvate formed)

126
Q

energy yield of citric acid cycle

A

6 NADH, 2 FADH2, 2 GTP per glucose

127
Q

1 NADH = ? ATP

A

2.5

128
Q

1 FADH2 = ? ATP

A

1.5

129
Q

Total energy yield from metabolism

A

30-32 ATP

130
Q

glycogenesis

A

build glycogen using 2 enzymes (glycogen synthase and branching enzyme)

131
Q

glycogen synthase

A

glycogen synthesis - creates alpha-1,4-glycosidic linkages b/w glucose molecules

activated by insulin in the liver and muscles

132
Q

branching enzyme

A

moves a block of oligoglucose from one chain and connects it as a branch using an alpha-1,6 glycosidic link

133
Q

glycogenolysis

A

breakdown of glycogen using 2 enzymes (glycogen phosphorylase and debranching enzyme)

134
Q

glycogen phosphorylase

A

removes single glucose 1-phosphate molecules by breaking alpha-1,4 glycosidic links

  • in liver, activated by glucagon to prevent low blood sugar
  • in muscle, activated by epinephrine and AMP to provide glucose to muscle
135
Q

debranching enzyme

A

moves a block of oligoglucose from one branch and connects it to the chain using an alpha-1,4 glycosidic link

136
Q

gluconeogenesis

A

occurs in cytoplasm and mitochondria, mostly in liver tho

reverse 3 irreversible steps

  1. pyruvate carboxylase and PEP carboxykinase bypass pyruvate kinase
  2. Fructose 1,6 bisphosphatase bypass phosphofructokinase-1
  3. glucose-6-phosphatase bypasses hexokinase/glucokinase
137
Q

pentose phosphate pathway

A

occurs in the cytoplasm of most cells - generates NADPH and sugars for biosynthesis.

138
Q

rate limiting step of pentose phosphate pathway

A

glucose-6-phosphate dehydrogenase activated by NADP+ and insulin, inhibited by NADPH

139
Q

postprandial metabolic state

A

well-fed (absorptive) - insulin secretion is high and anabolic metabolism prevails (building up molecules)

140
Q

postabsorptive metabolic state

A

fasting - insulin secretion decreases while glucagon and catecholamine secretion increases

141
Q

prolonged fasting metabolic state

A

starvation - dramatically increases glucagon and catecholamine secretion (most tissues relying on fatty acids)

142
Q

liver metabolism

A

maintains blood glucose thru glycogenolysis and gluconeogenesis

processes lipids, cholesterol, bile, urea, and toxins

143
Q

adipose metabolism

A

stores and releases lipids

144
Q

resting muscle metabolism

A

conserves carbohydrates as glycogen and uses free fatty acids for fuel

145
Q

active muscle metabolism

A

may use anaerobic metabolism, ox phosph, direct phosphorylation, fatty acid oxidation

146
Q

Cardiac muscle metabolism

A

fatty acid oxidation

147
Q

brain metabolism

A

uses glucose except in prolonged starvation (in which it will use ketolysis)

148
Q

lipid transport

A

chylomicrons, VLDL, IDL, LDL, HDL

149
Q

cholesterol metabolism

key enzyme?

A

obtained thru diet or synthesis in liver

HMG-CoA reductase

150
Q

Palmitic acid

A

the only fatty acid that humans can synthesize - produced in the cytoplasm from acetyl-CoA transported out of the mitochondria

151
Q

fatty acid oxidation

A

occurs in mitochondria after transport by the carnitine shuttle via beta-oxidation

shuttle - transfers long-chain fatty acids across the barrier of the inner mitochondrial membrane to gain access to the enzymes of beta-oxidation

152
Q

beta oxidation

A

catabolic process by which fatty acid molecules are broken down in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cycle, and NADH and FADH2, which are co-enzymes used in the electron transport

-the beta carbon of the fatty acid undergoes oxidation to a carbonylgroup

153
Q

ketogenesis

A

ketone bodies form during prolonged starvation state due to excess acetyl-CoA in the liver

154
Q

ketolysis

A

regenerates acetyl-CoA for use as an energy source in peripheral tissue

155
Q

protein digestion

A

occurs in SI, AA carbon skeletons used for energy, amino groups fed into urea cycle to be excreted

156
Q
A

Peeb MCAT (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions