Brainscape's Knowledge GenomeTM

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


See full index

MCAT Prep > Biochemistry > Flashcards

Biochemistry Flashcards

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

Amino Acids: w/ non-polar, non-aromatic side chains (7)

A

Glycine, Alanine, Valine, Leucine, Isoleucine, Methionine, Proline

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

Amino Acids: w/ Aromatic side chain, uncharged (3)

A

Tryptophan, Phenylalaline, Tyrosine

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

Amino Acids: w/ polar side chains (5)

A

Serine, Threonine, Asparagine, Glutamine, Cysteine

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

Amino Acids: w/ negatively charged, acidic side chains (2)

A

Aspartic Acid (aspartate), Glutamic Acid (glutamate)

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

Amino Acids: w/ positively charged, basic side chains (3)

A

Lysine, Arginine, and Histidine

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

Ionizable groups _____ protons under acidic conditions

A

gain protons

low pH tends to protonate groups

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

Ionizable groups _____ protons under basic conditions

A

lose protons

high pH tend to de-protonate groups

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

pka of carboxyl groups

A

2

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

pka of amino group

A

9-10

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

plane geometry of sp2 and sp3 hybridizations

A

sp2 bonds fall within the same plane

sp3 bonds do not fall within the same plane

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

Primary protein structure

A

linear (N term to C term)

stabilized by covalent bonds between adjacent amino aicds

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

Secondary protein structure

A

local structure, due to H bonding between near amino acids

alpha-helices and beta-pleated sheets

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

Tertiary protein structure

A

protein folding
determined by hydrophilic and hydrophobic interactions between R groups
and disulfide bonds

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

Quaternary Structure

A

not all proteins have this
aggregate multiple subunits, Hb
Purpose: reduce surface area, bring catalytic sites together

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

Enzyme Classifications (6)

A 
LI'L HOT
Oxidoreductases
Transferases
Hydrolases
Lysases
Isomerases
Ligases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Oxidoreductases

A

catalyze redox reactions
reductant (e- donor) and oxidant (e- acceptor)
common names: “dehydrogenase” “reductase” “oxidase”

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

Transferases

A

catalyze movement functional group from one to another

“kinases” catalyze movement of phosphate group

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

Hydrolases

A

catalyze breaking compound into two using H2O
“phosphatase, nucleases, lipase”
[substrate]hydrolase, [substrate]ase

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

Lyases

A

catalyze cleavage of a single molecule into two products (without water)
can catalyze the reverse
“synthase”

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

Isomerases

A

catalyze rearrangement of bonds within a molecule (stereoisomers and constitutional isomers)
-Can be considered oxidoreductase, transferase, lyase, but NOT ligase

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

Ligase

A

catalyze addition or synthesis reactions
require ATP (all ligases require it)
[substrate] synthase, [substrate] synthetase

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

5 ways to reduce activation energy

A
  1. Transition state stabilization
  2. Microenvironment Adjustments
  3. Adjusting substrate proximity
  4. Transient Covalent bonding
  5. Reactant destabilization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Apoenzymes

A

enzymes without their cofactor

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

Holoenzymes

A

enzymes with their cofactor

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

Prosthetic groups

A

tightly bound cofactors/coenzymes necessary for enzyme function

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

Cofactors

A

inorganic molecules, metal ions, ingested dietary minerals

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

Coenzymes

A

small organic groups, vitamins, their derivatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Water soluble vitamins

A 
ascorbic acid (vitamin C)
B complex vitamins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

B complex vitamins (1,2,3,5,6,7,9,12)

A 
1- thiamine
2- riboflavin
3- niacin
5- pantothenic acid
6- pyridoxal phosphate
7- biotin
9- folic acid
12- cyanocobalamin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Fat soluble vitamins

A

Vitamin A, D, E, K

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

Michaelis Menten constant

A 
Km = velocity at 1/2 Vmax
measure of E-S affinity
faster enzyme (greater affinity) low Km
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Types of Reversible Inhibitions

A

Competitive, noncompetitive, mixed, uncompetitive

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

Competitive Inhibition

A

occupies active site, inhibitor can completely block
-will be overcome by an increase in [S]
no effect on Vmax, increases Km

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

Noncompetitive Inhibition

A

bind to allosteric sites instead of active site (changes enzyme conformation)
do not compete for the same site, cannot be overcome by increase in [S]
decreases Vmax, no effect on Km

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

Mixed Inhibition

A

can bind to enzyme or E-S complex (different affinities)
binds at allosteric sites
changes Km depending on binding affinity
-if it prefers enzyme = increases Km
-if it prefers E-S complex = decreases Km

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

Uncompetitive Inhibition

A

bind only to ES complex, locks S in place and prevents release
decreases BOTH Vmax and Km

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

Irreversible Inhibition

A
  • active site unavailable for prolonged period
  • enzyme is permanently altered
  • prime drug mechanism
  • cannot reverse w/ removal of irreversible enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Regulated Enzymes (3)

A
  1. Allosteric Enzymes
  2. Covalently Modified Enzymes
  3. Zymogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Allosteric Enzymes

A

multiple binding sites

molecules binding to the allosteric site are either activators or inhibitors – causes a conformational change

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

Covalently Modified Enzymes

A

activated or deactivated by phosphorylations or dephosphorylation

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

Zymogens

A 
some enzymes are quite dangerous, and are released in their inactive forms
contain catalytic (active) domain and regulatory domain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

5 Primary Structure proteins

A
  1. Collagen
  2. Elastin
  3. Keratin
  4. Actin
  5. Tubulin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Collagen

A

extracellular matrix of connective tissue, strength and flexibility

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

Elastin

A

Important component of extracellular matrix of connective tissue
fx. straighten/recoil like a spring

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

Keratin

A

intermediate filament proteins in epithelial cells
fx. mechanical integrity of cells (hair and nails)
regulatory protein

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

Actin

A

component of microfilaments and thin filaments in myofibrils
most abundant in eukaryotic cells
polarity = allows motor proteins to travel unidirectionally

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

Tubulin

A

component of microtubules – structure, chromosome separation, intracellular support
polarity

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

3 Motor Proteins

A
  1. Myosin
  2. Kinesins
  3. Dyneins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Myosin

A

primary motor protein
interacts with actin
thick filament in myofibril and cellular transport

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

Kinesins

A

motor protein associated with microtubules

2 heads remain attached to tubulin always = aligns chromosomes

51
Q

Dyneins

A

associated with microtubules and 2 heads (one always attached to tubulin)

52
Q

Cell Adhesion Molecules (CAMs) (3)

A

Cadherins
Integrins
Selectins

53
Q

Cadherins

A

glycoproteins mediate calcium dependent cell adhesion

54
Q

Integrins

A

extracellular matrix binding, signaling, promoting cell adhesion

55
Q

Selectins

A

bind carbohydrate molecules, weakest type, expressed in cells that line blood vessels, vital role in inflammation and defense

56
Q

Biosignaling: Ion channels

A

via Facilitated Diffusion

  1. Ungated channels: no gates (potassium channels)
  2. Voltage-gated channels: regulated by membrane potential change
  3. Ligand-gated channels: binding to channel causes it to open and close
57
Q

Three primary protein domains (enzyme linked receptors)

A

Membrane-spanning Domain
Ligand-binding Domain
Catalytic Domain

58
Q

Electrophoresis

A

using an electric field
proteins move according to NET charge and SIZE
(-) charge moves towards (+) anode
(+) charge moves towards (-) cathode

59
Q

SDS-Page

A

disrupts all non covalent interactions = denature proteins

60
Q

Mutarotation

A

if hemiacetal is in water = spont. cycle in open and closed form

61
Q

IUPAC: Sucrose

A

glucose-alpha-1,2-fructose

62
Q

IUPAC: lactose

A

galactose-beta-1,4-glucose

63
Q

IUPAC: maltose

A

glucose-alpha-1,4-glucose

64
Q

Sphingolipids (and 5 types)

A 
structural lipids
-backbone: sphingosine or sphingoid
sphingophospholipids
sphingomyelins
glycosphingolipids
gangliosides
waxes
65
Q

Sphingophospholipids

A

may also be phospholipid w/ phosphodiester bond

66
Q

Sphingomyelins

A

contain phosphatidylcholine or phosphatidylethanolamine head group
-major component of myeline sheath

67
Q

Glycosphinogolipids

A

attached to sugar not phosphate

cerebrosides = one sugar attached, globosides = two or more sugars attached

68
Q

Gangliosides

A

oligosaccharides w/ 1 or more terminal N-acetylneuraminic acid

69
Q

Waxes

A

long chain fatty acids “esterified” to long chain alcohols

70
Q

two types of Signaling Lipids

A

Terpenes

Steroids

71
Q

Terpenes

A

odiferous steroid precursors from isoprene

terpenoids: from terpenes via oxygenation or backbone rearrangement

72
Q

Steroids

A

3 cyclohexane rings + 1 cyclopentane ring
steroid hormones: high affinity receptors (work event at low concentrations), gene expression and metabolism
Cholesterol
Prostaglandins
Fat Soluble Vitamins

73
Q

Steroids: Cholesterol

A

steroid in membrane fluidity and stability

74
Q

Steroids: Prostaglandins

A

autocrine and paracrine signaling, regulatory cAMP levels, effect smooth muscle contraction, body Temp, sleep/wake, pain, fever

75
Q

Steroids: Fat Soluble Vitamins

A

A: Carotene = retinol for vision, retinoic acid = epithelial development
D: Cholecalciferol = calcitriol in kidneys, regulates Ca and P, promotes bone formation
E: tocopherols = antioxidants, aromatic rings that destroy free radicals
K: Phylloquinone + menciquinones = promote clotting factor

76
Q

Purines

A

2 rings, Adenine and Guanine

77
Q

Pyrimidine

A

1 ring, cytosine, thymine, uracil

78
Q

Purine - Pyrimidine pairs

A

A – T

G – C

79
Q

Helicase

A

enzyme, unwinds DNA generating 2 ssDNA templates ahead of polymerase

80
Q

DNA topoisomerase

A 
function in response to supercoiling
introduce (-) supercoils
81
Q

Start codon

A

AUG

82
Q

Stop codons

A

UAA, UAG, UGA

83
Q

DNA to DNA

A

replication (new DNA synthesized in 5’ to 3’ direction

template read 3’ to 5’

84
Q

DNA to RNA

A

Transcription (new RNA synthesized 5’ to 3’ direction (template read 3’ to 5’)

85
Q

RNA to Protein

A

Translation (mRNA read 5’ to 3’ direction)

86
Q

“Wobble”

A

silent mutation tat affects the third base pair

protects against mutations

87
Q

Three types of RNA in transcription

A

mRNA: carries DNA nucleus to cytoplasm to be translated
tRNA: brings aa in, recognizes codons on mRNA using anticodon
rRNA: ribosome, enzymatically active, synthesized in nucleus

88
Q

Three metabolic states

A
  1. Postprandial state/Well-fed state
  2. Postabsorptive/Fasting state
  3. Prolonged fasting state (starvation)
89
Q

Postprandial state/Well-fed state

A

blood glucose rises, stimulating insulin release

90
Q

Postabsorptive/Fasting state

A

5 hours after food
counter regulating hormones: opposite effect of insulin on muscle, adipose tissue, liver
(Glucagon, Cortisol, Epinephrine, Norepinephrine, GH)
Glucogenolysis beings immediately, gluconeogenesis begins 12 hours later

91
Q

Prolonged fasting state (starvation)

A

higher glucagon levels, lower glycogen levels

increase [glucose] via gluconeogenesis

92
Q

levels of protein organization

A 
1 = string
2 = alpha helices and beta pleats
3 = interactions, disulfide bridges, H bonding, hydrophobicity
4 = multiple sub units
93
Q

Insulin in muscles does

A

entry of glucose
glycogen synthesis
protein synthesis

94
Q

Insulin in adipose tissue

A

entry of glucose

triacylglycerol synthesis

95
Q

Insulin in liver

A

glycogen synthesis

96
Q

Insulin in nervous tissue

A

obtains energy via oxidation of glucose to CO2 and water during well fed/normal states

  • grey matter: high glucose consumption
  • white matter: low glucose consumption
97
Q

Preferred fuel sources during well-fed and fasting state: liver

A

well fed: glucose, amino acids

fasting: fatty acids

98
Q

Preferred fuel sources during well-fed and fasting state: Resting skeletal muscle

A

well fed: glucose
fasting: fatty acids
prolonged fasting: ketones

99
Q

Preferred fuel sources during well-fed and fasting state: Cardiac muscle

A

well fed: fatty acids

fasting: fatty acids/ketones

100
Q

Preferred fuel sources during well-fed and fasting state: adipose tissue

A

well fed: glucose

fasting: fatty acids

101
Q

Preferred fuel sources during well-fed and fasting state: brain

A

well fed: glucose
fasting: glucose
prolonged fasting: ketones

102
Q

Preferred fuel sources during well-fed and fasting state: RBCs

A

well fed: glucose

fasting: glucose

103
Q

three types of cell-cell junctions

A

gap junctions
tight junctions
desmosomes

104
Q

gap junctions

A

rapid exchange of ions and other small molecules

105
Q

tight junctions

A

prevent paracellular transport

dont provide intercellular transport

106
Q

desmosomes

A

and hemidesmosomes

-anchor layers of epithelial tissue together

107
Q

three types of passive transport

A
  1. simple diffusion
  2. Osmosis
  3. Facilitated diffusion
108
Q

two more important types of glucose transporters

A

GLUT 2 = low affinity transporter=high Km
-found in the liver for glucose storage
-and in pancreatic beta-islet cells as a glucose sensor
GLUT 4 = high affinity = low Km
-found in adipose tissue and muscle = stimulated by insulin

109
Q

Glucokinase

A
  • converts glucose to glucose 6-phosphate
  • present in pancreatic Beta-islet cells (glucose sensor)
  • responsive to insulin in the liver
110
Q

Hexokinase

A

converts glucose to glucose 6-phosphate in peripheral tissues

111
Q

Phosphofructokinas-1 (PFK-1)

A
  • phosphorylates fructose 6-phosphate to fructose 1,6-biphosphate
  • RATE LIMITING STEP
  • stimulated by/activated by AMP and F 2,6-BP
  • inhibited by ATP and citrate
112
Q

Phosphofructokinase-2 (PFK-2)

A
  • produces F 2,6-BP
  • activates PFK-1
  • activated by insulin
  • Inhibited by glucagon
113
Q

Glyceraldehyde-3-phosphate dehydrogenase

A

produces NADH

feeds into ETC

114
Q

3-Phosphoglycerate Kinase (and pyruvate kinase)

A
  • each perform substrate level phosphorylation

- places inorganic phosphate (Pi) onto ADP

115
Q

NADH

A

produced in glycolysis
oxidized by mitochondria in ETC when O2 is present
If O2 and mitochondria are absent = NADH is oxidized by lactate dehydrogenase

116
Q

two types of monosaccharides and their functions

A

Galactose = lactose in milk, trapped in cell by galactokinase, converted to glucose 1-phosphate via galactose-1-phosphate

Fructose = honey, fruit, sucrose, commonly trapped in cell by fructokinase, cleaved by aldolase B = glyceraldehyde + DHAP

117
Q

Pyruvate Dehydrogenase

A

complex enzyme tat convert pyruvate to acetyl CoA
stimulated by insulin
inhibited by acetyl-CoA

118
Q

Glycogenesis

A

glycogen synthesis using 2 main enzymes

  • glycogen synthase: creates a-1,4-glycosidic links
  • branching enzyme: creates a-1,6-glycosidic links
119
Q

Glycogenolysis

A

breakdown of glycogen w/ 2 main enzymes

  • glycogen phosphorylase: breaks a-1,4 link
  • debranching enzyme: connects a-1,4 and breaks/releases the a-1,6 link
120
Q

Gluconeogenesis

A

located predominantly in liver (but also cytoplasm and mitochondria)

  • reverse of glycolysis
  • three main enzymes that bypass irreversible steps
    1. Pyruvate carboxylase
    2. Fructose-1,6 Biphosphate
    3. Glucose-6-Phosphate
121
Q

Pentose Phosphate Pathway

A

“hexose monophosphate (HMP) shunt”

  • located in cytoplasm
  • generates NADPH and sugars
  • rate limiting enzyme = glucose-6-phosphate dehydrogenase (activated by NADP+ and insulin, inhibited by NADPH)
122
Q

5 enzyme complex that produces Acetyl-CoA

A
  1. Pyruvate Dehydrogenase
  2. Dihydrolipoyl Transacetylase
  3. Dihydrolipoyl Dehydrogenase
  4. Pyruvate dehydrogenase kinase
  5. Pyruvate dehydrogenase phosphatase
123
Q

where does the citric acid cycle take place

A

in mitochondrial matrix

124
Q

8 important enzymes of citric acid cycle

A
  1. Citrate Synthase
  2. Aconitase
  3. Isocitrate dehydrogenase
  4. a-ketoglutarate dehydrogenase complex
  5. succinylcholine-CoA synthase
  6. Succinate dehydrogenase
  7. fumarase
  8. malate dehydrogenase

MCAT Prep (11 decks)

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