Biochem Flashcards
1
Q
Cells are broken apart by (hydrolysis/dehydration) and formed via (hydrolysis/dehydration).
A
-broken by hydrolysis and formed via dehydration
2
Q
function of phospholipids
A
serve as structural component of membranes
3
Q
function of triacylglycerols
A
store metabolic energy and provide thermal insulation and padding
4
Q
phosphodiester bond
A
phosphate group of one nucleotide and 3rd carbon of pentose sugar of another nucleotide
5
Q
Bending of polypeptide chain involves which level of protein structure?
A
tertiary
6
Q
(Unsaturated/Saturated) fats have a greater heat of combustion.
A
saturated fats are highly reduced allowing them to have higher energy storage potential
7
Q
Prokaryotic mRNA (polycistronic/monocistronic) and eukaryotic mRNA is (polycistronic/monocistronic).
A
prokaryotic mRNA- polycistronic
eukaryotic mRNA- monocistronic
8
Q
Where do transcription and post-transcriptional modifications take place in eukaryotes?
A
nucleus
9
Q
Transcription requires a (promoter/primer) whereas replication requires a (promoter/primer).
A
transcription-promoter
replication-primer
10
Q
Why is primase (RNA polymerase) needed for replication?
A
DNA polymerase cannot initiate new stand of nucleotides; it can only add nucleotides to an existing strand
11
Q
When does crossing over occur in meiosis?
A
prophase I- providing genetic recombination
12
Q
When does nondisjunction occur?
A
anaphase I/II
13
Q
steps for spermatogenesis
A
- spermatogonium
- primary spermatocyte
- secondary spermatocyte
- spermatid
- spermatozoa
14
Q
steps for oogenesis
A
- oogonium
- primary oocyte
- secondary oocyte
- ovum
15
Q
Primary oocyte is arrested at which meiosis stage?
A
Prophase I
16
Q
Secondary oocyte arrested at which meiosis stage?
A
Metaphase II
17
Q
Meiosis I starts with (diploid/haploid) with X chromosomes and Y chromatids.
A
- diploid
- 46 chromosomes
- 92 chromatids
18
Q
Meiosis II starts with (diploid/haploid) with X chromosomes and Y chromatids.
A
- haploid
- 23 chromosomes
- 46 chromatids
19
Q
Hardy-Weinberg Equilibrium
A
- no selection for fittest organism
- random mating
- large populations
- immigration/emigration must not change gene pool
- mutational equilibrium
20
Q
Where does glycolysis occur?
A
cytosol
21
Q
Where does the pentose phosphate pathway merge back with glycoslysis?
A
glyceraldehyde-3-phosphate (PGAL or G3P)
22
Q
What do fatty acids breakdown into?
A
acetyl-CoA through beta-oxidation
23
Q
Where does ketogenesis take place?
A
mitochondria of liver cells
24
Q
Glycolysis, glycogenesis, and lipid storage are (anabolism/catabolism).
A
anabolism
25
glycogenogenesis, glycogenolysis, beta oxidation, and ketone body synthesis are (anabolism/catabolism).
catabolism
26
Where does glycogenesis occur?
liver and muscle
27
Where does fatty acid synthesis occur?
liver
28
Where does the citric acid cycle take place?
mitochondrial matrix
29
Each turn of the citric acid cycle produces _ ATP, _ NADH, _ FADH2.
- 1 ATP
- 3 NADH
- 1 FADH2
30
Aerobic respiration, including glycolysis produces how many net ATP?
36 ATP
31
Aldehyde protons have a distinctive NMR shift at which ppm?
9.5 ppm
32
IR spectra for C=O
sharp dip at 1700 cm-1
33
IR spectra for OH
broad dip at 3200-3600 cm-1
34
vLDL is produced in which organ?
liver
35
Where does the Krebs cycle occur?
mitochondrial matrix
36
Where does the electron transport chain occur?
inner mitochondrial membrane
37
IR spectra for NH
sharp peak at 3300 cm-1
38
Which two amino acids are considered to be alpha helix breakers?
proline and glycine
39
What affect does pH have on conformational stability of proteins?
disrupts ionic bonds (3rd and 4th degree)
40
(T/F) mRNA is same as the coding strand
true except mRNA will have uracil instead of thymine
41
Where do prokaryotic ribosomes bind on the mRNA?
Shine-Dalgarno sequence
42
(Cytosine/Guanine) has one donor and two acceptors and (Cytosine/Guanine) has two donors and one acceptor
Cytosine (“C”) has one donor and two acceptors, and Guanine (“G”) has one acceptor and two donors.
43
function of histone acetyltransferase (HAT) and histone deacetylase (HDAC)
HAT-uncoiling of chromatin structure and increase transcription
HDAC- condensing chromatin structure and decrease transcription
44
Which type of mutation results in the sickle-cell disease phenotype?
glutamate → valine substitution is a non-conservative missense mutation
45
What is the function of ddNTP?
- termination of strand elongation for DNA sequencing (missing an oxygen)
- able to fluorescently label ddNTP to give DNA sequence
46
Penetrance
measures the fraction of people with the genotype who express the corresponding phenotype
47
Expressivity
measures the range of expression of a certain genotype; constant expressivity means that the genotype is expressed exactly the same way each time
48
fecundity
the ability to produce an abundance of offspring or new growth; fertility
49
genetic drift
random changes
50
bottleneck vs founder effect
bottleneck- population is drastically reduced via catastrophic event
founder effect-small group of individuals become isolated from larger population
51
(Spontaneous/nonspontaneous) reactions are defined as those whose products have a lower free energy than the reactants
spontaneous
52
(T/F) ATP is used in the pentose phosphate pathway
False
53
- What carbon molecule is needed to start the pentose phosphate pathway?
- What are the products of the PPP?
- glucose-6-phosphate
| - ribose-5-phosphate sugar and NADPH are the products
54
Where does the pentose phosphate pathway occur?
cytosol
55
What are the 3 most favorable (irreversible) steps of glycolysis?
hexokinase, phosphofructokinase, and pyruvate kinase
56
- NADH donates 2 e- to which complex of the ETC?
| - FADH2 donates 2 e- to to which complex of the ETC?
- protein complex 1
| - protein complex 2
57
How many protons do each of the complexes pump out?
- Complex 1 and 3 donate 4 H+
- Complex 4 donates 2H+
- Complex 2 donates 0 H+
*Complex I is known as NADH dehydrogenase, II is known as succinate dehydrogenase, III is known as cytochrome bc or c, and IV is known as cytochrome c oxidase
58
How many ATP are produced from 1 cycle of cellular respiration (per 1 glucose)?
-32 ATP (30-32 ATP)
59
Which enzyme is the rate limiting step for fatty acid synthesis?
Acetyl-CoA carboxylase
60
enzyme for transport of fatty acids for β-oxidation
- carnitine acyl transferase I
| - functions to transport fatty acids into the mitochondria for oxidization
61
Enzymes alter (thermodynamic/kinetic) properties of a reaction
Enzymes don't change any thermodynamic properties of a reaction only kinetic properties
62
All amino acids have S configuration with the exception of which one?
Cysteine has R configuration
63
Function of DNA Polymerase I, II, and III
DNAP I- removes the RNA primers and replaces them with newly synthesized DNA
DNAP II- recognize and repair incorrectly added nucleotides
DNAP III- extends the RNA primers by adding nucleotides in the 5′ to 3′ direction (replication)
64
Sanger sequencing
DNA sequencing based on the selective incorporation of chain-terminating dideoxynucleotides by DNA polymerase during in vitro DNA replication
65
in situ hybridization
uses a labeled complementary DNA, RNA or modified nucleic acids strand (i.e., probe) to localize a specific DNA or RNA sequence in a portion or section of tissue
66
immunohistochemistry
process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues
67
Which lipid type and temperature results in the most disordered membrane? (sat/unsat) and (low/high temp)
unsaturated and high temperature
68
Which enzymatic kinetic parameter is NOT affected by the presence of an uncompetitive inhibitor?
KM/Vmax
69
Specific activity measures what in enzymes?
the enzyme units per milligram of total protein in a solution
70
size-exclusion chromatography allows (large/small) molecules to pass more freely through column matrix
large
71
How many hydrogen atoms are removed in double bonds in an acyl chain compared with fully saturated chains?
- 4 hydrogen atoms
| - each double bond in an acyl chain removes two hydrogen atoms when compared with fully saturated chains
72
Uracil is produced from cytosine as a result of a conversion of what?
an amine group to a carbonyl group
73
rate-limiting enzyme for gluconeogenesis
fructose-1,6-bisphosphatase
74
rate-limiting enzyme for the pentose phosphate pathway
glucose-6-phosphate dehydrogenase
75
What is the main enzyme controlled in glycolysis?
Phosphofructokinase
| -high levels of ATP, citrate, or a more acidic pH decrease the enzyme’s activity
76
products of citric acid cycle
each turn gives: 1 GTP or ATP, 3 NADH molecules, and 1 FADH2 molecule
so total is 6 NADH and 2 FADH2 (1 glucose gives 2 TCA turns)
77
In oxidative phosphorylation, cytochrome c acts as (#) electron carrier
a 1-electron carrier
78
What type of bond is formed by glycogen synthase and the branching enzyme?
glycogen synthase- α-1,4-Glycosidic bond
| branching enzyme- α-1,6-Glycosidic bond
79
Antibodies participate in what type of bonds?
noncovalent protein interactions
80
All steroids are synthesized from what?
cholesterol (isoprene units)
81
Effects of entropy on hydrophobic and hydrophilic molecules in water
hydrophobic- decreased entropy
| hydrophilic- increased entropy (order increases)
82
noncovalent bonds
hydrogen bonds, ionic bonds, hydrophobic bonds, salt bridge
83
covalent bonds
```
disulfide bonds (formation cause oxidation), peptide bonds
*irreversible interactions
```
84
lineweaver-burk plot
slope= Km/Vmax
85
If a reaction has a +G is it thermodynamically stable or unstable?
unstable
86
cori cycle
lactate produced by anaerobic glycolysis in muscles is transported to the liver and converted to glucose, which then returns to the muscles
87
- gamma phosphate
- beta phosphate
- alpha phosphate
```
gamma= ATP
beta= ADP
alpha= AMP
```
88
TCA cycle uses which complex of the ETC?
Complex II
89
Which hormones support glycogenolysis?
glucagon and epinephrine
90
major sources of energy during starvation?
fatty acid oxidation and ketogenesis
91
Where does fatty acid oxidation and fatty acid synthesis occur?
fatty acid oxidation- mitochondria (convert FA to acetyl-CoA)
fatty acid synthesis- cytosol
92
Gel filtration chromatography
separates protein only on the basis of their size
93
Which two amino acids undergo deamidation to produce ammonia?
glutamine and asparagine
94
Which 2 ways can amino acids by formed?
gabriel synthesis and strecker synthesis
95
Which amino acid has an R configuration?
cysteine (C)
96
α helix
carbonyl (C=O) of one amino acid is hydrogen bonded to the amino H (N-H) of an amino acid that is four down the chain, pulling the chain into a helical structure
97
β pleated sheet
2+ segments of a polypeptide chain line up next to each other, forming a sheet-like structure held together by hydrogen bonds
98
protein stability
hydrophobic interactions and the increase of entropy in the solvation layer
99
cDNA cloning
- reverse transcriptase creates single strand of cDNA from target mRNA sequence
- DNA polymerase synthesize second complementary strand and amplify target cDNA sequence
- insert into plasmid vector via restriction enzymes
100
Where is ATP produced?
mitochondria
101
telomeres and centromeres are composed of (heterochromatin/euchromatin)
heterochromatin
102
Molecules that decrease TCA cycle activity?
NADH, ATP, citrate, succinyl-coA
103
pyruvate dehydrogenase complex
- oxidative decarboxylation of pyruvate to form acetyl-coA and reduction of NAD+ to NADH
- requires lipoic acid enzyme
104
fatty acids are oxidized into what?
acetyl-coA
105
formation of hemiacetal ring
intramolecular bond forming between the C1 hydroxyl and C5 carbonyl forms a ring which is the hemiacetal (enol) ring
106
hormone sensitive lipase
- hydrolyze fatty acids from triacylglycerides
| - increases with glucagon levels and decrease with insulin levels
107
cortisol is similar to insulin or glucagon?
glucagon
108
Ping-pong mechanism (double-displacement reaction)
change of the enzyme into an intermediate form when the first substrate to product reaction occurs
109
catalytic efficiency
- kcat/Km
| - Vmax=kcat[E]
110
Which type of inhibitor does NOT alter the Km/Vmax ratio of an enzyme?
Uncompetitive
111
hydrogen bonding of A, T, G, C
- Adenine contains 1 donor and 1 acceptor
- Thymine contains 1 donor and 1 acceptor
- Guanine contains 2 donors and 1 acceptor
- Cytosine contains 1 donor and 2 acceptors
112
High ATP, low ADP for glycolysis vs gluconeogenesis
glycolysis: inhibit
gluconeogenesis: activate
