Question 1
Question
This molecule is a product from:
Answer
-
glycolysis
-
gluconeogenesis
-
hexose phosphate pathway
-
anaerobic fermentation
-
beta-oxidation
Question 2
Question
The circled carbon position is:
Question 3
Question
The molecule can be used to produce glucose in gluconeogenesis is:
Question 4
Question
The molecule which facilitates the transport of fatty acyl-CoA into the mitochondria is:
Question 5
Question
The molecule produced by acetyl CoA carboxylase for fatty acid synthesis is:
Question 6
Question
The one whose cell surface localization is enhanced by insulin signaling pathway is?
Answer
-
Glut1
-
Glut2
-
Glut3
-
Glut4
-
SGLT
Question 7
Question
Which one is expressed abundantly on neuronal cells?
Answer
-
Glut1
-
Glut2
-
Glut3
-
Glut4
-
SGLT
Question 8
Question
Which one has a large Km and expressed mainly in hepatocytes and pancreatic alpha/beta-cells?
Answer
-
Glut1
-
Glut2
-
Glut3
-
Glut4
-
SGLT
Question 9
Question
Which one is abundantly expressed in red blood cells to ensure supply of glucose to erythrocytes?
Answer
-
Glut1
-
Glut2
-
Glut3
-
Glut4
-
SGLT
Question 10
Question
In which compartment of cell does fatty acid synthesis occur?
Answer
-
soluble cytoplasm (cytosol)
-
endoplasmic reticulum (ER)
-
Golgi complex
-
Mitochondrion (beta oxidation)
-
nucleus
Question 11
Question
After entering cells, the immediate product of the first reaction catalyzed by hexokinase is
Answer
-
glucose 6-phosphate
-
Fructose 1-phosphate
-
glucose 1-phosphate
-
Fructose 6-phosphate
-
glucose 3-phosphate
Question 12
Question
The major pathway responsible for maintaining blood glucose level 48 hours after a regular meal
is:
Question 13
Question
At 50 hours after a regular meal, in addition to glucose, another major carbon fuel supplied by liver to neurons is:
Answer
-
amino acids
-
fatty acids
-
fructose
-
ketone bodies
-
acetyl CoA
Question 14
Question
The most important rate limiting enzyme for glycolysis is
Answer
-
pyruvate kinase(also involved)
-
glyceraldehyde-3 phosphate dehydrogenase
-
Hexokinases(also invoved)
-
phosphoglycerate kinase
-
phosphofructose kinase 1(PFK1)
Question 15
Question
General effects of glucagon (increase blood glucose level) on skeletal muscle include:
Answer
-
glycolysis increases
-
glycogen synthesis is stimulated
-
glycogen synthase activity increases(sysnthsis more
glycogren)
-
glycated myoglobin increases (high levelm of glucose level)
-
glycogen breakdown increases
Question 16
Question
When glucagon (need more glucose) binds to cell surface receptors, which of the following response is unlikely?
Answer
-
hepatocytes: glycogen breakdown will be stimulated
-
adipocytes: fatty acid synthesis will be
stimulated
-
adipocytes: fatty acid release will be stimulated
-
hepatocytes: gluconeogenesis will be accelerated
-
skeletal muscle: glycogen breakdown will be stimulated
Question 17
Question
Under anaerobic condition, one of the products of the glycolysis, pyruvate, is converted to lactate. The biological importance of this reaction is:
Answer
-
To increase lactate levels in cells in order to enhance the expression of lactate dehydrogenase.
-
Lactate can reduce the intracellular pH, which helps the cell survival
-
This process is directly coupled with substrate level phosphorylation, hence
making ATP
-
To oxidize NADH to NAD+, a required cofactor for glycolysis; so ATP production via
glycolysis can continue
-
Without oxygen, neurons use lactate as a fuel supply
Question 18
Question
The pyruvate dehydrogenase complex is mainly located:
Question 19
Question
Ketone bodies can be utilized by the following organs, except for:
Answer
-
brain
-
liver
-
heart
-
skeletal muscle
-
kidney
Question 20
Question
Deficiency of fatty acyl-CoA dehydrogenase may lead to:
Question 21
Question
The following molecules are involved in fatty acid biosynthesis, except for:
Answer
-
Pyruvate carboxylase (coveert to oxdiatate)
-
malonyl CoA
-
fatty acid synthase (FAS)
-
acetyl CoA carboxylase
-
malic enzyme (in the cytochrome, cutralic get cleaved,use4d NADP as a cofator)
Question 22
Question
Pyruvate dehydrogenase complexes uses several cofactors which require the following vitamins as precursor, except for:
Answer
-
vitamin B3
-
vitamin B5(co
A)
-
vitamin B2
-
vitamin B1
-
vitamin B6
Question 23
Question
When some amino acids are utilized as carbon sources, the first step is to remove the amino group by transamination with alpha-KG, which requires a cofactor derived from
Answer
-
vitamin
B6
-
vitamin
B5
-
vitamin
B7
-
Vitamin
B1
-
vitamin
B3
Question 24
Question
The catabolism of odd-numbered fatty acids requires the following vitamins,
except for:
Answer
-
vitamin
B2
-
vitamin
B3
-
vitamin
B12
-
vitamin
B7
-
vitamin
B1
Question 25
Question
Which of the following statements regarding oxidation of fatty acids for ATP production is incorrect?
Answer
-
The acyl-CoA needs translocation into mitochondrial matrix
-
The first step is ATP-dependent activation of fatty acids to form acyl-CoA, using two
ATP equivalent per fatty acid molecule.
-
The translocation step needs carnitine and translocases, also known as
CAT, which is rate-limiting
-
The beta-oxidation enzymes are generally located in the mitochondrial matrix
-
unsaturated fatty acids cannot be catabolized by beta-oxidation (CAN be)
Question 26
Question
Glycogen storage disease may be caused by the deficiency of the following enzymes, except for:
Question 27
Question
Pancreas (endocrine, extrocine) is important for human metabolism because it produces the following, except for:
Answer
-
glucocorticoids
-
lipases
-
glucagon
-
protease
-
insulin
Question 28
Question
The rate limiting step in fatty acid biosynthesis is:
Answer
-
malonyl CoA association with fatty acid synthase (FAS)
-
acetyl CoA carboxylation by ACC to form malonyl CoA
-
citrate break down by citrate lyase to form acetyl CoA and OAA in the cytosol
-
dehydrogenation of malate in the cytosol by malic enzyme
-
the final step, release of palmitate from FAS
Question 29
Question
About glycogenin expression and subcellular localization the right combination is:
Answer
-
myocyte: endoplasmic reticulum
-
cardiac myocyte: peroxisome
-
hepatocyte: cytosol
-
adipocyte: mitochondrion
-
myocyte: mitochondrion(of myocyte and cytosol then this answer could be
right)
Question 30
Question
Which of the following enzymes has the least influence on the speed of glycolytic pathway?
Answer
-
phosphoglycerate mutase
-
pyruvate kinase
-
hexose kinase
-
phosphofructose kinase 1
-
phosphofructose kinase 2
Question 31
Question
About AMPK, which one of the following statements is incorrect?
Answer
-
Exercise may activate its activity in myocytes (muscle cells)
-
It synergizes with insulin, and represses the expression of PEPCK in hepatocyte
-
It is an intracellular energy sensor regulating the energy metabolism at the cellular level
-
It is a molecule binds and synergizes with insulin to promote glycolysis in multiple
tissues (binds is wrongs)
-
It is a protein kinase activated by increased level of AMP in cells
Question 32
Question
The rate of pentose phosphate pathway is limited by G6PD activity, which is allosterically inhibited by:
Answer
-
Decrease of intracellular NADPH levels
-
Decrease of mitochondrial NADPH levels
-
Increase of ribose-phosphate levels
-
Increase of intracellular NADPH levels
-
Decrease of ribose phosphate levels
Question 33
Question
Reduced glutathione (GSH) level has been reported to be critical for the recovery of Covid-19 patients. Low intracellular levels of NADPH may cause:
Answer
-
high level of GSH, high level of
GSSG
-
irrelevant to the levels of GSH
and GSSG
-
high level of GSH, low level of
GSSG
-
low level of GSH, high level of
GSSG
-
low level of GSH, low level of
GSSG
Question 34
Question
Which of the following statements about lipid digestion and absorption is NOT correct?
Answer
-
chylomicron carries a protein called Apo protein B100 on its surface
-
chylomicrons will be transported to the circulation via lymph duct
-
malabsorption causes lack of essential fatty acids and lipid soluble vitamins
-
digestion needs lipases secreted by pancreas and bile juice from gallbladder
-
absorbed lipids will be incorporated into chylomicrons, which is released by intestinal mucosa
Question 35
Question
During starvation, AMP increase in hepatocytes indicates ATP depletion which stimulates AMPK activity. A well-known activity of AMPK is to phosphorylate acetyl CoA carboxylase.(inhibate fatty acid systhesis) This phosphorylation will:
Answer
-
block glycolysis
-
decrease fatty acid synthesis
-
inhibit TCA cycle
-
stimulate acetyl CoA carboxylase activity
-
Increase fatty acid synthesis
Question 36
Question
After an Italian spaghetti meal an increase of blood glucose levels to 12 mM will significantly increase the activity of:
Answer
-
Glut3
-
Glut1 and Glut3
-
Glut1
-
Glut1, Glut 2 and Glut3
-
Glut2
Question 37
Question
Fructose 2, 6-bisphosphate is:
Answer
-
An intermediate product of catabolism of fructose to generate ATP
-
An intermediate metabolite in fatty acid synthesis
-
An intermediate product of glycolysis which promote the release of O2
-
A waste byproduct of the glycolytic pathway
-
A regulatory molecule that allosterically stimulates PFK1 activity and the glycolytic pathway
Question 38
Question
Completely oxidation of one mole of hexanoyl CoA (an 6C, fully saturated fatty acyl CoA) in mitochondrion maximally may generate:
Answer
-
8 mole ATP
-
38 mole ATP
-
42 mole
ATP
-
30 mole ATP
-
12 mole ATP
Question 39
Question
Historically, which term was used to indicate the glycolytic processes in normal eukaryotic cells?
Question 40
Question
For fatty acid biosynthesis, each round contains four reactions. Which of the following accurately describes the four reactions in the correct order?
Answer
-
Condensation-reduction-hydration-reduction
-
Condensation-dehydrogenation-reduction, reduction
-
Condensation-reduction-dehydration-reduction
-
Condensation-reduction-dehydrogenation-reduction
-
Dehydrogenation, condensation, dehydration,
reduction
Question 41
Question
In pentose phosphate pathway, after two steps of oxidation, the end products
from one molecule of G6P will be:
Answer
-
one NADH, one NADPH and one
ribose phosphate
-
two NADH and one pentose phosphate
-
one NADPH and one pentose phosphate
-
two NADPH and two pentose phosphate
-
two NADPH and one pentose phosphate
Question 42
Question
In a lipogenic liver, the beta oxidation pathway is repressed mainly by:
Answer
-
Increased level of malonyl CoA, which represses CAT activity, thus slowing down the translocation of acyl-CoA to mitochondria
-
Increased glucagon level, thus promoting the utilization of glucose, repressing utilization of fatty acids
-
Increase of Ca++ in mitochondrial matrix, which speed up TCA cycle and increased ATP inhibits beta-oxidation
-
Lack of ATP, fatty acids cannot be activated
-
Lipogenesis depletes ATP, which activates AMPK and inhibits energy consumption, so cell does not need a fast beta oxidation
Question 43
Question
Generally, the effects of epinephrine (adrenaline) (make atp in skeletal muscle) on hepatocytes (increase glucose level to sketel mucscle) may include:
Answer
-
inhibiting glycogen breakdown
-
enhancing glycogen synthase activity
-
inhibiting glycolysis
-
stimulating glycogen synthesis
-
inhibiting glucogenolysis
Question 44
Question
Which of the following correctly describes the sequence of events of beta-oxidation of fatty acyl CoA in mitochondria?
Answer
-
dehydrogenation-dehydrogenation-hydration-cleavage
-
dehydrogenation-hydration-dehydrogenation-cleavage
-
dehydrogenation-hydration-dehydration -cleavage
-
dehydrogenation-dehydration-dehydrogenation-cleavage
-
hydration-dehydrogenation-dehydrogenation-cleavage
Question 45
Question
In gluconeogenesis, how many moles of ATP are required to synthesize one mole glucose from 2 moles of OAA?
Question 46
Question
The mobilization and utilization of endogenous TAG may not include:
Answer
-
beta-oxidation, resulting in cleavage by thiolase to form acetyl CoA in mitochondrion
-
ATP-dependent activation of free fatty acid to form acyl-CoA in the cytosol
-
insulin signaling activates hormone sensitive lipase on white adipose tissue (adipocytes), which releases fatty acids
-
transport free fatty acids by the circulatory system to cells which need fatty acids as fuel
-
translocation of acyl-CoA into mitochondria, a carnitine-dependent process
Question 47
Question
Which of the following carbon sources cannot be used in gluconeogenesis?
Answer
-
OAA from aspartate catabolism
-
riboses from pentose pathway
-
acetyl CoA from beta oxidation
-
glycerol-3 phosphate released from breakdown of
phospholipids
-
alpha-ketoglutarate from glutamate and glutamine catabolism
Question 48
Question
About insulin, which of the following statement is NOT correct?
Answer
-
its target organs/tissues include liver, muscle and adipose
-
its release is triggered by increased ATP levels in β cells
-
it promotes glycogen phosphorolysis and glycolysis to generate large amount of ATP in muscle (not promote glycogen phosphorolysis)
-
it may regulate the expression of metabolic enzymes.
-
it is produced by pancreatic β cells
Question 49
Question
Insulin stimulates PI3K-PKB pathway, which may lead to:
Answer
-
converting phosphorylated glucose to glucose
-
converting glycogen phosphorylase
a to phosphorylase b
-
converting glycogen synthase a to glycogen
synthase b
-
increasing internalized Glut4
-
converting glycogen phosphorylase b to phosphorylase a
Question 50
Question
Some steps in the glycolytic pathway cannot be simply reversed in gluconeogenesis, thus need bypassing by different enzymes; these steps include the following, except for:
Answer
-
hexokinase-catalyzed formation of G6P
-
pyruvate kinase-catalyzed formation of pyruvate
-
PFK1-catalyzed formation of F1,6BP
-
Phosphoenolpyruvate to pyruvate, accompanied by substrate level phosphorylation
-
F1,6BP broken by aldolase
Question 51
Question
About ketone bodies, which of the following statement is not correct?
Answer
-
are produced by hepatocytes
-
can be used by all tissues, such as neurons and hepatocytes
-
is an alternative fuel, particularly important for brain
-
are produced from acetyl CoA
-
overproduction of ketone bodies may occur in diabetic patients, even with hyperglycemia
Question 52
Question
Which process is NOT considered a general function of the pentose phosphate pathway?
Answer
-
The production of pentose phosphate for biosynthesis of some cofactors
-
the production of NADPH to help prevent oxidative stress in erythrocytes
-
The transfer of electrons to the electron transport chain for ATP production
-
the production of pentoses necessary for nucleotide synthesis
-
the production of NADPH for reductive biosynthesis in adipose cells
Question 53
Question
In humans, the Cori cycle is an example of metabolic coordination among active skeletal muscle, the circulatory system and liver. Which two metabolic pathways are involved in this cycle?
Answer
-
gluconeogenesis in muscle and glycogenolysis in liver
-
glycolysis in muscle and gluconeogenesis in liver
-
glycolysis in muscle and the pentose phosphate
pathway in liver
-
pentose phosphate pathway in muscle and
gluconeogenesis in liver
-
beta-oxidation in muscle and ketogenesis in liver
Question 54
Question
In some cell types, insulin signaling will triggers the glucose transporter 4 translocating to the cell membrane, hence increasing the transport of glucose into cells. Which cell types respond to insulin in this manner?
Answer
-
hepatocytes and skeletal myocytes
-
erythrocytes and neurons
-
erythrocytes and adipocytes
-
skeletal myocytes and adipocytes
-
neurons and the hepatocytes
Question 55
Question
Under anaerobic conditions, yeast performs two additional steps after glycolysis; which convert pyruvate to ethanol. What is the purpose served by these two additional steps in the metabolism of yeast cells?
Answer
-
They know our students like beer.
-
They are required to complete the oxidation of glucose and maximizing ATP production
-
They are required to re-oxidize limited amounts of NADH to NAD+ and decrease pyruvate level, thus sustaining continuous glycolysis to ensure ATP production
-
They are required to remove pyruvate, ensuring ATP production.
-
They are required to oxidize NADH to generate ATP
Question 56
Question
Which of the following carbon sources cannot be used in gluconeogenesis in human cells?
Answer
-
succinyl-CoA
-
aspartate
-
palmitate
-
glutamate
-
alanine
Question 57
Question
Which statement is accurate, regarding fatty acids stored in adipocytes?
Answer
-
They are part of the cell components, and cannot be oxidized for energy in this tissue.
-
They are primarily bound to albumin and stored in lipid droplets.
-
There is a constant movement of fatty acids in and out of adipose tissues, which is independent of hormone signals.
-
Upon glucagon signaling, fatty acids are converted into ketone bodies in adipocytes
-
In adipocytes, fatty acids up-taken from the bloodstream are assembled into triglycerides by directly esterifying to glycerol.
Question 58
Question
Which statement is INCORRECT regarding the transport of long-chained fatty acids into the mitochondrial matrix?
Answer
-
The cytosolic and mitochondrial matrix pools of coenzyme A are separated by biomembranes
-
It is not a rate-limiting step in the oxidation of these fatty acids.
-
Once these fatty acyl molecules are in the matrix, carnitine can be transported out of mitochondria.
-
It is inhibited by the increase of malonyl-CoA levels
-
Patients with a carnitine deficiency are likely to have impaired betaoxidation of fatty acids
Question 59
Question
For catabolism of the amino acids with hydroxyl groups, the amino groups are usually removed by:
Answer
-
decarboxylation initiated deaminination
-
hydrolysis to remove α-amino group
-
transamination to remove α-amino
group
-
dehydration initiated deamination
-
oxidative deamination
Question 60
Question
Pentose phosphate pathway has two phases: the oxidative phase and the non-oxidative phase.
Question 61
Question
PLP is a cofactor required for glycogen phosphorylase activity, which is derived from vitamin B6.
Question 62
Question
Human fatty acid synthase is an enzyme complex of 7 subunits, each with a specialized activity. ( for human we have 1 only)
Question 63
Question
beta-oxidation of fatty acids also occurs in peroxisomes, which similarly has
ETC to make ATP. N(peroxisome do not have ETC)
Question 64
Question
The oxidized glutathione protects enzymes from oxidative damage. (used
reduced)
Question 65
Question
G6P phosphatase is an enzyme specifically expressed in hepatocytes.
Question 66
Question
Completely oxidation of one mole of hexanoyl CoA (an 6C, fully saturated fatty acyl CoA) in mitochondrion maximally may generate:
Answer
-
30 mole ATP
-
32 mole ATP
-
42 mole ATP
-
48 mole ATP
-
38 mole ATP
Question 67
Question
Each round of beta-oxidation has 4 steps. The correct order of the four steps are:
Answer
-
dehydrogenation to generate FADH2, Reduction, dehydrogenation to generate NADH, cleavage to for to acetyl CoA and a new acyl CoA.
-
dehydrogenation to generate FADH2, Hydration, dehydrogenation to generate NADH, cleavage to for to acetyl CoA and a new acyl CoA.
-
dehydrogenation to generate NADH, Hydration, dehydrogenation to generate FADH2, cleavage to for to acetyl CoA and a new acyl CoA.
-
dehydrogenation to generate FADH2, dehydration, dehydrogenation to generate NADH, cleavage to for to acetyl CoA and a new acyl CoA.
Question 68
Question
For beta oxidation of fatty acids as energy, the rate limiting step is:
Answer
-
transportation into mitochondria
-
biosynthesis of fatty acyl CoA in the mitochondria
-
Activation by ATP
-
biosynthesis of fatty acyl-CoA in the cytosol
-
Fatty acyl CoA dehydrogenation
Question 69
Question
Regarding propionyl-CoA metabolism, which of the following statement is incorrect?
Answer
-
Propionyl-CoA is a rare metabolite, which cannot be further catabolized by human cells, thus being disposed by urine
-
further converting methylmalonyl-Coa to succinyl-CoA depends on vitamin B12
-
Propionyl-CoA may arise from diet, or catabolism of fatty acids and some amino acids.
-
Propionyl-CoA (3C) can be converted to Methylmainyl-CoA (4C) after a carboxylation reaction facilitated by vitamin B7
-
The structure of vitamin B12 is very complicate and contains cobalt.
Question 70
Question
In glycolysis pathway, the energy released during the breakdown of glucose to pyruvate is harvested or stored by:
Answer
-
ATP and NADH
-
NADH
-
FADH2
-
phosphoenolpyruvate
Question 71
Question
Biochemical features of glycolysis include the following, except for:
Question 72
Question
About the overall steps of digestion and absorbtion of dietary fatty acids, which of the following is correct?
Answer
-
After absorption to mucosa cells, free fatty acids are used to re-synthesize TAG, which is then packed into chylomicron.
-
chylomicron is transported to liver via portal vein, an via hepatic vein to reach circulation
-
Fat digested to free fatty acids, which are absorbed into mucosa cells and released into blood circulation directly.
-
chylomicron is purely compose of lipids, without protein components.
Question 73
Question
In amino acid catabolism, amino-transferases remove the alpha-amino groups in transamination reactions. This type of enzymes requires an important cofactor derived from:
Question 74
Question
Pyruvate dehydrogenase complex contains 3 enzymatic activities, sequentially named E1,E2 and E3.
Which of the following description of the E1-E3 is correct?
Answer
-
E1: pyruvate dehydrogenase; E1: pyruvate transacetylase; E3: dihydrolipoyl dehydrogenase
-
E1: pyruvate decarboxylase; E2: dihydrolipoyl transacetylase; E3: dihydrolipoyl dehydrogenase
-
E1: pyruvate dehydrogenase; E2: dihydrolipoyl transacetylase; E3: dihydrolipoyl dehydrogenase
-
E1: pyruvate dehydrogenase; E2: dihydrolipoyl dehydrogenase; E3: dihydrolipoyl transacetylase
-
E1: dihydrolipoyl dehydrogenase; E2: dihydrolipoyl transacetylase; E3: pyruvate dehydrogenase
Question 75
Question
Historically, which term was used to indicate the glycolytic processes in normal eukaryotic cells?
Question 76
Question
After uptaking into cardiomyocyte, a 18C-fatty acid will be likely utilized in the following order:
Answer
-
Synthesized into fatty acyl CoA, transported into, Activation by ATP, beta-oxidation to generate Acetyl coA
-
Activation by ATP in cytosol, converting to Fatty acyl CoA, transported into mitochondrion, beta-oxidation to generate Acetyl coA
-
Activation by ATP in cytosol, converting to Fatty acyl CoA, beta-oxidation to generate Acetyl coA, transporting acetyl coA into mitochondrion
-
Activation by ATP in cytosol, transported into mitochondrion, converting to Fatty acyl CoA, beta-oxidation to generate Acetyl coA
-
Transported into mitochondrion, activation by ATP, converting to fatty acyl CoA, beta-oxidation to generate Acetyl coA
Question 77
Question
For catabolism of the amino acids with hydroxyl groups, the amino groups are usually removed by:
Answer
-
dehydration initiated deamination
-
transamination to remove a-amino group
-
hydrolysis to remove a-amino group
-
decarboxylation initiated deaminination
-
oxidative deamination
Question 78
Question
The catabolism of odd-numbered fatty acids requires the following vitamins, except for:
Question 79
Question
About anaerobic glycolysis, which of the following statement is incorrect?
Answer
-
In human cells, anaerobic glycolysis generates alcohol, which later on degraded by alcohol dehydrogenase to acetaldehyde upon reoxygenation.
-
Anaerobic glycolysis in human cells generates lactate, not alcohol
-
Anaerobic glycolysis to produce ATP is developed earlier than oxidative phosphorylation method evolutionarily.
-
in some bacteria, anaerobic glycolysis generates lactate to recover NAD+ (oxidized)
-
In yeast, anaerobic glycolysis generates alcohol to regenerated NAD+ (oxidized)
Question 80
Question
The most important regulatory enzyme of glycolytic pathway is:
Answer
-
phosphofructokinase-1 (PFK1), which converts F6P to F1,6BP.
-
phosphoglycerate kinase, which catalyzes the first production of ATP
-
Glyceraldehyde-3-phospate dehydrogenase, which catalyzes the generation of NADH
-
Aldolase A, which breaks the 6C hexose-phosphate to 3C triose phosphate
-
pyruvate kinase, which chatalyzes the 2nd production of ATP
Question 81
Question
In gluconeogenesis, the rate limiting enzymes are:
Answer
-
phosphofructose kinase 1
-
PEP carboxykinase
-
pyruvate kinase
-
pyruvate carboxylase
-
F1,6 bisphosphatase
Question 82
Question
Fatty acid biosynthesis requires high concentrations of NADPH. Which compartment of human cell does fatty acid synthesis occur?
Question 83
Question
The rate limiting step of fatty acid synthesis is:
Answer
-
condensation of malony-CoA with growing fatty acyl chain
-
beta oxidation to generate acetyl CoA as substrates
-
transfer citrate out of mitochondria
-
recognizing and binding malonyl CoA by Acyl carrier protein (ACP)
-
carboxylation of acetyl CoA to form malonyl CoA
Question 84
Question
Glycogen storage disease may be caused by the deficiency of the following enzymes, except for:
Question 85
Question
Deficiency of a fatty acyl-CoA dehydrogenase may lead to:
Question 86
Question
About glycogenin expression and subcellular localization the right combination is:
Answer
-
myocyte: mitochondrion
-
cardiac myocyte: peroxisome
-
hepatocyte: mitochondrion
-
hepatocyte: cytosol
-
myocyte: endoplasmic reticulum
Question 87
Question
Completely oxidizing a G6P to 6CO2 via the pentose pathway may result in:
Answer
-
4 NADPH
-
8 NADPH
-
6 NADPH
-
12 NADPH
-
2 NADPH
Question 88
Question
For fatty acid biosynthesis, each round contains four reactions. Which of the following correctly describes the four reactions in the correct sequence?
Answer
-
Condensation-reduction-dehydrogenation-reduction
-
Dehydrogenation, condensation, dehydration, reduction
-
Condensation-dehydrogenation-reduction, reduction
-
Condensation-reduction-dehydration-reduction
-
Condensation-reduction-hydration-reduction
Question 89
Question
The major products of pentose pathway with important biological roles is/are:
Question 90
Question
1. The single most important enzyme involved in glycogen synthesis is:
Question 91
Question
Hepatocytes synthesize fatty acids, and most of the fatty acids are esterified into TAG, which will be:
Answer
-
released to circulation directly and carried by plasma proteins
-
carried by a lipoprotein called VLDL through the circulation
-
carried by a lipoprotein called LDL through the circulation
-
carried by either VLDL or chylomicron through the circulation
-
carried by a lipoprotien called chylomicron through the circulation
Question 92
Question
In most cells, reduced glutathione is used to protect cells from damage caused by reactive oxygen species. The most important metabolic pathway that maintains the intracellular levels of reduced glutathione is:
Question 93
Question
After biosynthesis, palmitate can be elongated to stearate in either mitochondria or endoplasmic reticulum. Both palmitate or stearate can be modified by desaturation at delta9, which is catalyzed by an enzyme located at:
Question 94
Question
Glycolysis contains 10 steps, among which 7 steps are reversible and 3 steps are not reversible in glyconeogenesis. The three non-reversible steps are:
Answer
-
A. hexokinase catalyzed Glucose to G6P
-
B. phosphofructokinase (PFK) catalyzed F6P to F1, 6BP
-
C. Pyruvate kinase catalyzed PEP to enol pyruvate
-
A, B, and C
-
A and B
Question 95
Question
The most important substrate/s for gluconeogenesis upon starvation is/are:
Answer
-
carbon skeletons from catabolism of most amino acids
-
fatty acids from TAG break down
-
propionyl-CoA from catabolism of odd-numbered fatty acids
-
glycerol from TAG breakdown
-
acetyl CoA from fatty acid beta-oxidation