Please confirm for me if the following answers are correct. Thank you
1.Which of the
following tissues can use glucose, but not fatty Acids, as a source of fuel?
A. Skeletal Muscle
B. Cardiac tissue
D. Red Blood Cells
E. Adipose: D. Red Blood Cells
Brain and RBC
2.Within the red blood cell, NADPH is required for which of the following processes?
A. The Conversion of pyruvate to Acetyl CoA
B. The Oxidation of hemoglobin
C. The conversion of pyruvate to lactate
D.The synthesis of ribulose 5-Phosphate
E. The Reduction of Glutathione:
Answer: E. The Reduction of Glutathione
3.There are several anaplerotic reactions required to replenish intermediates of the TCA cycle. All of the following compounds can be used for these anaplerotic reactions EXCEPT:
D.Odd Chain fatty acids
Answer: E. Glucose
CAN BE USED: Pyruvate, Aspartate, Glutamate, Beta Oxidation of fatty acids, adenylosuccinate; PEP carboxylase and malate dehydrogenase; Glutamine
4.Hereditary fructose intolerance is a rare recessive disease caused by a mutation in exon 5. The mutation creates a new Ahall restriction within the exon. In this graphic:
——— ——— 306
===== ——— ===== ——— 183
===== ——— ===== ——— 123
husband wife jack jill
a) the husband had al b deficiency
b) the wife has 2 wild allells
c) Jill has wild recessive
d) jack and jill have same genes:
Answer: b) the wife has 2 wild allells
5.A 3-year-old boy who presented with generalized hypotonia, severe psychomotor development delay, and severe lactic acidosis following ingestion of a high carbohydrate meal was diagnosed with a deficiency in pyruvate dehydrogenase (X-linked recessive).
Supplementation of which vitamin may be beneficial to this individual:
A. Pyridoxal Phosphate (PLP)
C. Cobalmin (B12)
Answer: D. Thiamine
6.Which of the following hormones binds to a receptor tyrosine kinase?
Answer: D. Insulin
Receptor tyrosine kinase are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Tyrosine kinase contain insulin growth factor which can bind to glucogan
7.Which of the following is true regarding single point mutations to a genomic DNA sequence?
A . changes to the DNA sequence will always resu in an amino acid change in the primary sequence
B. single nucleotide changes to the DNA sequence may have no impact on the primary sequence of a protein
C. single nucleotide changes to DNA will always introduce a frame shift
D. single nucleotide changes will always introduce a nonsense mutation:
8.NADH generated in the cytosol must be transported across the mitochondrial membrane in order to be oxidized by the electron transport chain. Which can be used to facilitate movement of cytosolic NADH into the mitochodria?
a) Malate-aspartate shuttle
b) GLUT 4 Transport
c) Citrate chuttle
d) Na/K+ ATPase pump:
Answer: a) Malate-aspartate shuttle
NADH generated in the cytosol must be transported across the mitochondrial membrane in order to be oxidized by the electron transport chain,which can be used to facilitate movement of cytosolic NADH into the mitochodria.this meshanism is called shuttle mechanism.
9.Prokaryotic genes are organized which contain a series of genes that are regulated by a common promoter. In the case of an inducible operon, the operaon is transcribed:
a) when the inducer is bound tt the repressor
b) when the repressor is bound to the operator
c) when the inducer is bound ot the operator
d) when both the repressor and inducer are bound to the operator:
Answer: A) when the inducer is bound tt the repressor
10.When the pancreatic beta cells sense an increase in glucose, the release of insulin is facilitated through which of the following mechanisms?
a) increase in intracellular calcium
b) incrase in intracellular potassium
c) decrease in intracellular ATP
d) decrease in intracellular Calcium:
Answer: A) an increase in intracellular calcium.
11.You have identified a mutation in the c subunit in the ATP synthase. The mutation changes the glutamate residue, (that facilitates proton pumping into the mitochondrial matrix), to a glycine. The inability to dissipate the proton gradient will have which of the following impacts on the electron transport chain?
A) Decreased ATP synthesis
B) Increased ATP synthesis
C) Increased NADH oxidation
D) Increased Oxygen Consumption:
12.During an overnight fast, which of the following pathways is the primary source of glucose required for the maintenance of blood glucose levels?
A) Lipolysis from adipose stores
B) Muscle glycogenolysis
C) Muscle Protein Catabolism
D) Liver Glycogenolysis:
Answer:D) Liver Glycogenolysis
Liver glycogen is broken down for gluconeogenesis.
13.Glycogen synthesis and degradation in the liver and muscle is very similar. Which of the following enzymes is not used in both muscle and liver for those metabolic pathways?
A) Glycogen Phosphorylase
C) Glycogen synthase
E) UDP- Glucose pyrophosphorylase:
14.Insulin is a peptide hormone secreted by the beta cells of the pancreas in response to elevated levels of blood glucose. Locally, insulin will inhibit the release of glucagon from alpha cells in the pancreas, and it will also impact the metabolism of many peripheral tissues. The actions of insulin are best described as which of the following?
b) paracrine and autocrine
d) paracrine and endocrine:
Answer:(d) Paracrine and endocrine
Insulin acts as a messenger to instruct the body’s cells to absorb glucose, in effect reducing blood glucose levels.
15.Rotenone is an inhibitor of complex 1 in the electron transport chain. Which of the following will not occur as a resu of the addition of rotenone?
A) Decreased Oxidation of FADH2
B) Decreased production of ATP
C) Decreased oxygen consumption
D) Decreased oxidation of NADH:
Answer: A) Decreased Oxidation of FADH2
The addition of rotenone to the ETC does what? – inhibits transfer of electrons from complex 1 to CoQ (prevents NADH from entering complex 1)
-H+ movement ceases
-ATP not synthesized
16.Based on the following schematic, which statement best describes the acid/base properties of guanine?
Image Link – http://oi68.tinypic.com/ogwbp0.jpg
A ) at physiological pH, guanine will be positively charge
B ) at physiological pH, guanine will be negatively charge
C) at physiological pH, guanine will be neutral
D) at physiological pH, guanine will be an effective buffer against a base
E) at physiological pH, guanine will be an effective buffer against an acid:
-at pH, guanine will be neutral
17.Following a meal, fructose 2, 6 bisphosphate levels will be elevated in the liver. Under these conditions which of the following will be dephosphorylated and inactive?
a) pryuvate kinase
b) glycogen synthase
d) glycogen phosphorylase:
Answer: b) glycogen synthase
18.Given the following enzyme pathway, A→B→C→D
And given that the ΔG0′ for A→B is -8; for B→C is +6; and for C→D is +1
Then the ΔG0′ for A→D is:
E) -2: simple subtraction: -1
19.In the liver, the pyruvate dehydrogenase complex (PDC) would be dephosphorylated and active when which of the following compounds or hormones is elevated?
Answer: E) glucagon
20.All of the following are part of the Cori Cycle EXCEPT:
A) ATP is produced by the conversion of lactate to glucose
B) Lactate is the resu of anaerobic glycolysis in a number of tissues
C) Lactate travels to the liver
D) Lactate is converted to glucose in the liver
E) Glucose travels from liver to other tissues:
Answer: A) ATP is produced by the conversion of lactate to glucose
ATP is produced by the conversion of lactate to glucose
Lactate is the resu of anaerobic glycolysis in a number of tissues
Lactate travels to the liver
Lactate is converted to glucose in the liver
Glucose travels from liver to other tissues
21.Which of the following is a monosaccharide?
Answer: C) Galactose
22.Which of the following compounds or hormones will not facilitate the process of skeletal muscle glycogenolysis?
C) Ca ++
Answer: C) Ca ++
23.The primary GLUT transporter used by the liver is ____________ and the primary GLUT transporter used by the skeletal muscle is _______________:
A) GLUT4; GLUT2
C) GLUT2 ; GLUT4
D) GLUT5; GLUT2:
Answer: C) GLUT2, GLUT4
24.Glucogan will influence the metabolism in the liver, adipose, and skeletal muscle during fasting. Which of the following is consistent with the impact of glucogon?
A) Glucogan will increase output of glucose by liver
B) triaglycerol synthesis in adipose
C) oxidation of glucose in muscle
D) oxidation of glucose in live:
Answer: A) Glucogan will increase output of glucose by liver
Because glucogan control the mechanism of glycogenolysis and gluconeogenesis under the fasting condition glucogan provide the glucose by these two mechanism
25.Chronic smokers have an elevation of guanine residues associated with a benzopyrene ring. This bulky distortion to the DNA is repaired through which of the following mechanisms?
A) Nucleotide excision repair
B) Bases excision repair
C) Mismatch repair
D) Homologous end joining:
Answer: A) Nucleotide excision repair
26.Under conditions of anaerobic glycolysis pyruvate is primarily oxidized to which compound:
c) Acetoly CoA
Answer: B) Lactate
27.Insulin is a major metabolic hormone. Its Primary role on metabolism is best summarized by which of the following statements?
A) It mobilizes glycogen stores during acute stress
B) It activates processes to mobilize fuel stores
C) It stimulates protein synthesis during fasting
D) it promotes fuel storage and growth after a meal:
Answer: D) it promotes fuel storage and growth after a meal
Insulin secret from pancrease by Beta cells it function into control blood sugar level. so it can control it by mobilize fuel because our major fuel is sugar.
28.Certain conditions such as excessive alcohol consumption can increase the ratio of NADH/NAD+ in the mitochondria. This will directly inhibit which of the following enzymes?
b) PDC (kinase)
d) succinate thiokinase:
Answer: B) PDC – Pyruvate Dehydrogenase Complex
29.The oxidation of glucose produces NADH. NADH can be oxidized in the mitochondria and in this process the terminal electron acceptor in the electron transport chain is which of the following compounds?
Answer: c) O2
30.What is the oxidizing agent in the following reaction?
^oh (Ethanol) + NAD+ = o=^h (Acetaldehye ) + NADH + H+
Answer: B) NAD+ is the oxidizing agent in this reaction because it is getting reduced by consuming one electron. Whichever product is reduced, i.e. gains an electron (- / H+) ]
31.Several TCA cycle intermediates can be used as a substrate for the synthesis of other compounds. Succinyl CoA is an intermediate that is directly used for the synthesis of which of the following compounds?
Answer: C) Heme
32.A 2-year-old boy is recently diagnosed with red-green color blindness which is an X-linked recessive disorder. Which of the following represents the genotype of this individual?
A) X’Y ( X’ recessive X allele and Y chromosome)
B) Rr (one wildtype autosomal allele and one recessive allele)
C) XY ( X – wild type X allele and Y chromosome
D) rr ( two recessive autosomal alleles):
Answer: A) X’Y ( X’ recessive X allele and Y chromosome)
33.Dinitrophenol is an uncoupler of the electron transport chain. The addition of dinitrophenol will have which of the following impacts to the cell?
a) increase oxygen consumption
b) increase ATP production
c) decrease NADH oxidation
d) increase protein concentration in the cytosol:
Answer: a) increase oxygen consumption
34.Under conditions when a cell only needs to use the nonoxidative portion of the pentose phosphate pathway to synthesize ribose 5-phosphate, the elevated levels of NADPH in the cell will inhibit which of the following enzymes?
B) alpha-ketoglutarate dehydrogenase
D) G-6-phosphate dehydrogenase
E) Glucose 6- phosphatase:
Ribose 5-P only needed, so only the nonoxidative reactions. High NADPH inhibits glucoe-6-phosphate dehydrogenase, so transketolase and transaldolase are used to convert fructose 6-P and glyceraldehyde 3-P to ribose 5-P.
35.Which of the following intermediates is a feed-forward activator of pyruvate kinase?
C) Fructose 6 Phosphate
D) Glyceraldehyde-3- phosphate
36.Which of the following activators is correctly paired with the glycolytic or TCA cycle enzyme that it activates?
A) Glucose-6-Phosphate : Hexokinase
B) ATP: alpha-ketoglutarate dehydrogenase
C) ATP: Pyruvate kinase
D) Fructose-2-6-biphosphate : phosphofructokinase 1 (PFK1)
E) Citrate : citrate synthase:
Answer:D) Fructose-2-6-biphosphate : phosphofructokinase 1 (PFK1)
37.Skeletal muscle does not have the enzyme glucose 6-phosphatase, which is required to dephosphorylate glucose-6-P released during the process of glycogenolysis. As a resu of this, glucose 6-P released from muscle glycogen stores is primarily used for which of the following processes?
A ) it enters the glycolytic pathway and is oxidized
B) it helps maintain blood glucose levels
C ) it is used for protein synthesis
D ) it is used as a substrate for glycogen synthesis:
Answer: A) it enters the glycolytic pathway and is oxidized
38.In the red blood cell, glucose can be oxidized to two primary products. One of the oxidation products is ribulose 5-phosphate, and the other is which of the following compounds?
A) Acetyl CoA
B) Carbon Dioxide
39.Besides its role in glycogen synthesis, which of the following directly relies on UDP-glucose?
A) galactose metabolism
D) sucrose metabolism
E) fructose metabolism:
Answer:A) galactose metabolism
40.Hereditary fructose intolerance (HFI) is a rare recessive disorder that is caused by a mutation in the aldolase B gene. As a resu of this disorder individuals may have all of the following symptoms EXCEPT:
a) inability to metabolize lactose
b)reduced blood glucose levels during fasting
c)reducing sugar in the urine
Answer:a) inability to metabolize lactose
– WILL NOT HAVE:
-inability to metabolize lactose
-reduced blood glucose levels during fasting
-reducing sugar in the urine
41.When glucagon binds its receptor there is an increase in the second messenger, cAMP. cAMP levels can be decreased by which of the following enzymes?
A) Adenylyl cyclase
B) Protein Kinase A
C) Phosphoinositide-dependent protein kinase (PDK 1)
42.Which of the following statements best describes the action of epinephrine?
a) It promotes of fuel storage after a meal
b) It promotes of protein synthesis
c) facilitates maintenance of glucose during fasting
d) it works to mobilized fuels during acute stress:
Answer:d) it works to mobilized fuels during acute stress
increased release of glucose
43.An individual with a deficiency in Pyruvcute stressate Dehydrogenase Complex (PDC) will have elevated levels of which metabolite after consuming a meal high in carbohydrates?
44.Phenylketonuria (PKU) is an autosomal recessive disorder that can be caused by a defect in phenylalanine hydroxylase. Phenylketonuria can also present due to a deficiency in which of the following vitamins or cofactors?
A) Tetrahydrobiopterin (BH4)
B) Cobalmin (B12)
C) Pyridoxal Phosphate (B6)
D) Tetrahydrofolate (TH4):
Answer:A ) cofactor: Tetrahydrobiopterin (THB, BH4)
45.Under conditions of strenuous exercise, gluconeogenesis occurs primarily in the _______ using _______ formed in the skeletal muscle.
A) liver; lactate
B) liver; propionate
C) kidney; acetyl-CoA
D) kidney ; alanine
E) Muscle ; glycerol: A) liver; lactate
46.The movement of glucose from the intestinal lumen into the blood stream requires secondary active transport. Which type of work is required?
a) Transport work
b) passive work
c) mechanical work
d) biochemical work:
Answer: a) Transport work
47.A substitution mutation occurs in the GRE (glucocorticoid response element) making it unrecognizable to the glucocorticoid receptor. What impact would this have on the transcription of the gene downstream of this element?
a) transcription unchanged but mutation incorporated into transcript
b) transcription unchanged but translation increased
c) increased translation of downstream gene
d) decreased translation of downstream gene: b) transcription unchanged but translation increased
48.NADPH is used by most cells for which of the following processes?
A) To produce ribose-5-P from glyceraldehyde-3-P and fructose-6-P
B) A reducing agent in detoxification reactions
C) An oxidizing agent in reductive biosynthesis
D) A substrate for transketolase reactions:
Answer:B) A reducing agent in detoxification reactions
49.When Ca++ increases in muscle cells, muscle contracts and all of the following happen EXCEPT:
A) The oxidation of NADH and FADH2 by the electron transport chain increases
B) Isocitrate dehydrogenase and alpha-keto glutarate dehydrogenase are allosterically activated by increases in NADH
C) Isocitrate dehydrogenase is allosterically activated by increases in ADP
D) Isocitrate dehydrogenase and alpha-keto glutarate dehydrogenase are allosterically activated by increases in Ca++
E) The concentration of AMP and ADP increase and the concentration of ATP decreases:
Answer:B) Isocitrate dehydrogenase and alpha-keto glutarate dehydrogenase are allosterically activated by increases in NADH
50.The mechanism of action of the pyruvate dehydrogenase complex (PDC) relies on the use of three prosthetic groups in the enzyme active site. Which of the following lists these three groups in the order that they are utilized during the oxidation of pyruvate?
A) NAD+ ; FAD ; Lipoate
B) FAD ; Thiamine pyrophosphate ; NAD+
C) Thiamine pyrophosphate; Lipoate; FAD
D) FAD ; Thiamine pyrophosphate ;Lipoate:
Answer:C) Thiamine pyrophosphate; Lipoate; FAD
thiamine pyrophosphate (TPP), Lipoamide (and Coenzyme A),
1. Pyruvate dehydrogenase
2. Dihydrolipoyl transacetylase
3. Dihydrolipoyl dehydrogenase
1.E1: Pyruvate dehydrogenase which uses thiamine pyrophosphate (TPP) as its prosthetic group.
2.E2: Dihydrolipoyl transacetylase which uses lipoamide and coenzyme A (also known as coASH) as its prosthetic groups.
3.E3: Dihydrolipoyl dehydrogenase which uses flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NAD+) as its cofactors.