中国大学Biochemistry_1答案(慕课2023课后作业答案)

点击查看答案

Chapter1 Introduction to Metabolism

quiz1

1、中国作业Which one below is 大学答案答案NOT a kind of high energy compound?
A、ATP
B、慕课G-6-P
C、课后Glycerate-1,中国作业3-bisphosphate
D、Phosphocreatine

2、大学答案答案Enzymes are potent catalysts because they:
A、慕课are consumed in the reactions they catalyze.
B、课后are very specific and can prevent the conversion of products back to substrates.
C、中国作业increase the equilibrium constants for the reactions they catalyze.
D、大学答案答案lower the activation energy for the reactions they catalyze.

3、慕课Which statement about allosteric control of enzymatic activity is 课后FALSE?
A、Allosteric effectors give rise to sigmoidal V versus [S] kinetic plots.
B、中国作业An effector may either inhibit or activate an enzyme.
C、大学答案答案Binding of the effector changes the conformation of the enzyme molecule.
D、慕课Heterotropic allosteric effectors compete with substrate for binding sites.

4、A small molecule that DECREASES the activity of an enzyme by binding to a site other than the catalytic site is termed a(n):
A、allosteric inhibitor.
B、alternative inhibitor.
C、competitive inhibitor.
D、stereospecific agent.

5、Which amino acid is NOT one that may be targeted for phosphorylation to modulate the activity of an enzyme?
A、Tyr
B、Ser
C、Ala
D、Thr

6、Which type of enzyme is responsible for attaching phosphate groups to specific amino acids?
A、a protein phosphatase
B、a protein kinase
C、a protein glycosylase
D、an ATPase

Chapter2 Carbohydrate Metabolism

quiz2

1、Which reaction in glycolysis requires ATP as a substrate?
A、hexokinase
B、glyceraldehyde-3-phosphate dehydrogenase
C、pyruvate kinase
D、aldolase

2、Which reaction in glycolysis produces ATP as a product?
A、hexokinase
B、glyceraldehyde-3-phosphate dehydrogenase
C、pyruvate kinase
D、phosphofructokinase-1

3、During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal muscle must be reoxidized to NAD+ if glycolysis is to continue. The most important reaction involved in the reoxidation of NADH is:
A、dihydroxyacetone phosphate → glycerol 3-phosphate.
B、pyruvate → lactate.
C、isocitrate → α-ketoglutarate.
D、oxaloacetate → malate.

4、The anaerobic conversion of 1 mol of glucose to 2 mol of lactate by fermentation is accompanied by a net gain of:
A、1 mol of ATP.
B、1 mol of NADH.
C、2 mol of ATP.
D、2 mol of NADH.

5、In comparison with the resting state, actively contracting human muscle tissue has a:
A、higher concentration of ATP.
B、higher rate of lactate formation.
C、lower consumption of glucose.
D、lower rate of consumption of oxygen

6、Which compound CANNOT serve as the starting material for the synthesis of glucose via gluconeogenesis?
A、acetate
B、glycerol
C、lactate
D、oxaloacetate

7、An enzyme used in both glycolysis and gluconeogenesis is:
A、3-phosphoglycerate kinase.
B、glucose 6-phosphatase.
C、hexokinase.
D、phosphofructokinase-1.

8、Which statement about gluconeogenesis is FALSE?
A、For starting materials, it can use carbon skeletons derived from certain amino acids.
B、It consists entirely of the reactions of glycolysis, operating in the reverse direction.
C、It employs the enzyme glucose 6-phosphatase.
D、It is one of the ways that mammals maintain normal blood glucose levels

9、In humans, gluconeogenesis:
A、can result in the conversion of protein into blood glucose.
B、helps to reduce blood glucose after a carbohydrate-rich meal.
C、is essential in the conversion of fatty acids to glucose.
D、requires the enzyme hexokinase.

10、Which statement about the pentose phosphate pathway is CORRECT?
A、It generates 36 mol of ATP per mole of glucose consumed.
B、It is a reductive pathway; it consumes NADH.
C、It is present in plants, but not in animals.
D、It provides precursors for the synthesis of nucleotides.

11、The metabolic function of the pentose phosphate pathway is to:
A、act as a source of ADP biosynthesis.
B、generate NADPH and pentoses for the biosynthesis of fatty acids and nucleic acids.
C、participate in oxidation-reduction reactions during the formation of H2O.
D、provide intermediates for the citric acid cycle.

12、Which compound(s) is/are a high-energy intermediate(s) in glycolysis?
A、fructose 1,6-bisphosphate
B、NADH
C、1,3-bisphosphoglycerate and phosphoenol pyruvate
D、fructose 1,6-bisphosphate, 1,3-bisphosphoglycerate, and phosphoenol pyruvate

13、Malonate is a competitive inhibitor of succinate dehydrogenase. If malonate is added to a mitochondrial preparation that is oxidizing pyruvate as a substrate, which compound would you expect to decrease in concentration?
A、citrate
B、fumarate
C、isocitrate
D、pyruvate

14、Which compound is NOT an intermediate of the citric acid cycle?
A、acetyl-CoA
B、citrate
C、oxaloacetate
D、succinyl-CoA

15、In mammals, what process does NOT occur during the citric acid cycle?
A、formation of α-ketoglutarate
B、generation of NADH and FADH2
C、metabolism of acetyl-CoA to carbon dioxide
D、net synthesis of oxaloacetate from acetyl-CoA

16、Conversion of 1 mol of acetyl-CoA to 2 mol of CO2 and CoA via the citric acid cycle results in the net production of:
A、1 mol of citrate.
B、1 mol of FADH2.
C、1 mol of NADH.
D、1 mol of oxaloacetate.

17、Which factor is NOT associated with the oxidation of substrates by the citric acid cycle?
A、CO2 production
B、FADH2
C、NADH
D、NADPH

18、Which enzymatic activity would be decreased by thiamine deficiency?
A、α-ketoglutarate dehydrogenase complex
B、isocitrate dehydrogenase
C、malate dehydrogenase
D、fumarase

19、The reaction of the citric acid cycle that produces an ATP equivalent (in the form of GTP) by substrate level phosphorylation is the conversion of:
A、succinyl-CoA to succinate.
B、citrate to isocitrate.
C、fumarate to malate.
D、succinate to fumarate.

20、Which cofactor is required for the conversion of succinate to fumarate in the citric acid cycle?
A、ATP
B、biotin
C、FAD
D、NAD+

21、Which process is NOT a metabolic fate for pyruvate in liver tissue?
A、reduction to lactate
B、oxidative decarboxylation to acetyl-CoA
C、phosphorylation to phosphoenolpyruvate
D、carboxylation to oxaloacetate

22、Covalent modification is one way the activity of specific enzymes can be regulated. Which enzyme is NOT regulated in this way?
A、phosphofructokinase-2
B、pyruvate dehydrogenase
C、phosphorylase kinase
D、All of these enzymes are regulated by covalent modification.

23、Which statement about mammalian glycogen synthase is NOT correct?
A、It is especially predominant in liver and muscle.
B、The donor molecule is a sugar nucleotide.
C、The phosphorylated form of this enzyme is active.
D、This enzyme adds the initial glucose unit to a tyrosine residue in glycogenin.

24、Which statement is TRUE of glycogen synthase?
A、Activation of the enzyme involves a phosphorylation.
B、It catalyzes addition of glucose residues to the nonreducing end of a glycogen chain by formation of (α1 -4) bonds.
C、It uses glucose-6-phosphate as donor of glucose units
D、The enzyme has measurable activity only in liver.

25、Which statement is TRUE of muscle glycogen phosphorylase?
A、It catalyzes phosphorolysis of the (α1-6) bonds at the branch points of glycogen.
B、It degrades glycogen to form glucose 6-phosphate.
C、It exists in an active (a) form and an inactive (b) form that is allosterically regulated by AMP.
D、It removes glucose residues from the reducing ends of the glycogen chains.

26、Which statement is TRUE of glycogen synthesis and breakdown?
A、Phosphorylation activates the enzyme responsible for breakdown, and inactivates the synthetic enzyme.
B、Synthesis is catalyzed by the same enzyme that catalyzes breakdown.
C、The immediate product of glycogen breakdown is free glucose.
D、Under normal circumstances, glycogen synthesis and glycogen breakdown occur simultaneously and at high rates.

27、Glycogen phosphorylase a can be inhibited at an allosteric site by:
A、AMP.
B、glucose.
C、GDP.
D、calcium.

28、Starting from glucose, what is the net number of NTP molecules used in the synthesis of glycogen?
A、zero
B、one
C、two
D、three

29、What will be the net yield of ATP (per glucose unit) starting from glycogen and ending at pyruvate?
A、1 ATP
B、2 ATP
C、3 ATP
D、4 ATP

30、Which method of directly regulates PFK-I?
A、allosteric activation by AMP
B、feedback inhibition by fructose 2,6-bisphosphate
C、allosteric activation by citrate
D、feed forward activation by phosphoenolpyruvate

Homework

1、Synthesis of L -Malate in Wine Making ： The tartness of some wines is due to high concentrations of L -malate. Write a sequence of reactions showing how yeast cells synthesize L -malate from glucose under anaerobic conditions in the presence of dissolved CO 2 (HCO 3 ? ). Note that the overall reaction for this fermentation cannot involve the consumption of nicotinamide（Vitpp） coenzymes.

Chapter3 Biology Oxidation

quiz3

1、Which statement regarding oxidative phosphorylation is TRUE?
A、The rate of electron transport is independent of the magnitude of the proton electrochemical gradient.
B、ATP synthase utilizes oxidized cofactors.
C、Proton transfer through the Fo subunit of ATP synthase is required in order for ATP synthesis to occur.
D、The addition of an uncoupler decreases the rate of re-oxidation of NADH and FADH2, therefore decreasing the rate of the citric acid cycle.

2、The electron-transport chain and ATP synthase are effectively coupled. Which statement BEST describes how this occurs?
A、The electron-transport chain reoxidizes reduced cofactors.
B、The electron-transport chain generates an electrochemical gradient that provides energy for the production of ATP.
C、ATP synthase utilizes oxidized cofactors.
D、Through a series of conformational changes, ATP synthase generates ATP.

3、Which statement is NOT true of electron transport?
A、The mobile electron carrier coenzyme A is located in the inner mitochondrial membrane.
B、Electrons flow from redox centers with a lower reduction potential to redox centers with a higher reduction potential.
C、The electron transport chain oxidizes reduced cofactors.
D、Cytochrome C has a higher reduction potential than FADH2.

4、During oxidative phosphorylation, the proton motive force (electrochemical gradient) that is generated by electron transport is used to:
A、create a pore in the inner mitochondrial membrane.
B、reduce O2 to H2O.
C、drive transport processes essential to oxidative phosphorylation.
D、reduce NAD+ to NADH.

5、Complex III contains which cofactor as a prosthetic group?
A、iron-sulfur clusters
B、FAD
C、FMN
D、coenzyme Q

6、Which statement is FALSE regarding 2,4-dinitrophenol?
A、It decreases ATP synthesis will increasing oxygen consumption.
B、It requires a specific transporter to enter mitochondria.
C、It is a proton carrier.
D、It is soluble in the lipid core of membranes.

7、Which statement is FALSE regarding ATP synthase?
A、ADP binds more tightly to the active site than ATP.
B、ATP synthase can be classified as a transporter.
C、The catalytic site is F1.
D、Fo is hydrophobic.

8、Antimycin A blocks electron transfer between cytochromes b and c1. If intact mitochondria were incubated with antimycin A, excess NADH, and an adequate supply of O2, which compound would be found in the oxidized state?
A、coenzyme Q
B、NAD
C、FAD
D、cytochrome aa3

9、Cyanide, oligomycin, and 2,4-dinitrophenol (DNP) are inhibitors of mitochondrial aerobic phosphorylation. Which statement CORRECTLY describes the mode of action of the three inhibitors?
A、Cyanide and 2,4-dinitrophenol inhibit the respiratory chain, and oligomycin inhibits the synthesis of ATP.
B、Cyanide inhibits the respiratory chain, whereas oligomycin and 2,4-dinitrophenol inhibit the synthesis of ATP.
C、Cyanide, oligomycin, and 2,4-dinitrophenol compete with O2 for cytochrome oxidase (Complex IV).
D、Oligomycin and cyanide inhibit synthesis of ATP; 2,4-dinitrophenol inhibits the respiratory chain.

10、If electron transfer in tightly coupled mitochondria is blocked with rotenone, then:
A、all ATP synthesis will stop.
B、ATP synthesis will continue, but the P/O ratio will drop to one.
C、O2 uptake will cease.
D、electron transfer from succinate to O2 will continue unabated.

11、In normal mitochondria, the rate of NADH consumption (oxidation) will:
A、be increased in active muscle, decreased in inactive muscle.
B、be very low if the ATP synthase is inhibited, but increase when an uncoupler is added.
C、decrease if mitochondrial ADP is depleted.
D、All of the answers are correct.

12、Which statement about the chemiosmotic theory is CORRECT?
A、Electron transfer in mitochondria is accompanied by an asymmetric release of protons on one side of the inner mitochondrial membrane.
B、It predicts that oxidative phosphorylation can occur, even in the absence of an intact inner mitochondrial membrance.
C、The effect of uncoupling reagents is a consequence of their ability to carry electrons through membranes.
D、The membrane ATP synthase has no significant role in the chemiosmotic theory.

13、Which statement about the chemiosmotic theory is FALSE?
A、Electron transfer in mitochondria is accompanied by an asymmetric release of protons on one side of the inner mitochondrial membrane.
B、The membrane ATPase has no significant role in the chemiosmotic theory.
C、Energy is conserved as a transmembrane pH gradient.
D、Oxidative phosphorylation cannot occur in membrane-free preparations.

14、Which statement about energy conservation in the mitochondrion is FALSE?
A、Drugs that inhibits the ATP synthase will also inhibit the flow of electrons down the chain of carriers.
B、For oxidative phosphorylation to occur, it is essential to have a closed membranous structure with an inside and an outside.
C、The yield of ATP per mole of oxidizable substrate depends on the substrate.
D、Uncouplers (such as dinitrophenol) have exactly the same effect on electron transfer as inhibitors such as cyanide; both block further electron transfer to oxygen.

15、Which statement is CORRECT concerning the mitochondrial ATP synthase?
A、It is actually an ATPase and only catalyzes the hydrolysis of ATP.
B、It consists of Fo and F1 subunits.
C、It can synthesize ATP after it is extracted from broken mitochondria.
D、It catalyzes the formation of ATP even though the presence of oligomycin.

16、The relative concentrations of ATP and ADP control the cellular rates of:
A、glycolysis.
B、oxidative phosphorylation.
C、the citric acid cycle.
D、All of the answers are correct.

17、The rate of oxidative phosphorylation in mitochondria is controlled primarily by:
A、feedback inhibition by CO2.
B、the availability of NADH from the TCA cycle.
C、the concentration of citrate (or) the glycerol-3-phosphate shuttle.
D、the mass-action ratio of the ATD-ADP system.

Chapter4 Lipids Metabolism

4.11 Metabolism of plasma cholesterol随堂测验

1、Which statement is NOT a step in the uptake of cholesterol from the bloodstream into cells?
A、The ApoB-100 protein is degraded.
B、LDL containing ApoB-100 is recognized by the LDL receptor.
C、LDL bound to the LDL receptor leads to endocytosis of the complex.
D、The cholesteryl esters in the LDL are hydrolyzed to release free cholesterol.

2、Which factor does NOT contribute to lowering the risk of atherosclerosis?
A、statin drugs
B、HDL
C、reverse cholesterol transport
D、foam cells

quiz4

1、If the palmatic acid is catabolized completely, to carbon dioxide and water, the net yield of ATP per molecule of fatty acid is _____ ATP.
A、90.5
B、97.5
C、106
D、108

2、If 1 mol of a fatty acyl-CoA containing 20 carbon atoms undergoes three rounds of β oxidation, how many mol of ATP are produced from the complete aerobic catabolism of the products of these three rounds? (The remaining acyl-CoA is NOT catabolized further.)
A、12 ATP
B、30 ATP
C、37.5 ATP
D、42 ATP

3、In mammals, which intermediate of carbohydrate metabolism CANNOT relieve ketosis?
A、lactate
B、acetyl-CoA
C、fumarate
D、succinyl-CoA

4、Which statement is TRUE regarding fatty acids in adipocytes?
A、They are primarily bound to albumin and stored in lipid droplets.
B、They cannot be oxidized for energy in this tissue.
C、In adipocytes, fatty acids from the bloodstream are assembled into triglycerides by esterifying them to glycerol.
D、There is constant movement of fatty acids in and out of adipose tissues that is independent of hormone signals.

5、What is the role of lipoprotein lipase?
A、It hydrolyzes triacylglycerols of plasma lipoproteins to supply fatty acids to various tissues.
B、It aids intestinal uptake of dietary fat.
C、It initiates intracellular lipid breakdown of lipoproteins.
D、It degrades lipoproteins in order to supply needed amino acids to various tissues.

6、What is the major site of the formation of β-hydroxybutyrate from fatty acids?
A、intestinal mucosa
B、kidney
C、liver
D、adipose tissue

7、Which statement is FALSE regarding the catabolic oxidation of 1 mol of palmitate?
A、8 mol of acetyl-CoA are formed.
B、The oxidation reactions occur in the mitochondria.
C、8 mol of H2O are required.
D、Carnitine is required for the transport of fatty acids into the mitochondrial matrix.

8、What is the extra product resulting from the β-oxidation of a saturated fatty acid with 19 carbons as compared to that of a fatty acid with 18 carbons?
A、acetoacetyl-CoA
B、succinyl-CoA
C、malonyl-CoA
D、propionyl-CoA

9、Which statement is FALSE regarding ketone bodies?
A、During prolonged starvation, the brain adapts to using ketone bodies as a fuel.
B、Excess acetone production during ketoacidosis is exhaled through the lungs.
C、Ketone bodies are formed when the glucagon/insulin ratio is high.
D、Ketone bodies can be converted to glucose during ketosis.

10、Which compound is NOT considered a “ketone body”?
A、acetoacetate
B、β-hydroxybutyrate
C、dihydroxyacetone
D、acetone

11、Some athletes believe that dietary carnitine supplements will enhance their ability to perform aerobic exercise. Which statement BEST describes the “scientific” basis of this belief?
A、Carnitine is required in the transport of medium and long-chain fatty acids into the mitochondrial matrix, and so increasing the amount of carnitine will increase the rate of transport.
B、Carnitine activates carnitine-acyl transferase-1 (CAT-I) thereby increasing the rate of transport of fatty acids into the mitochondrial matrix.
C、Carnitine levels in the cytoplasm are reduced when large amounts of fatty acyl carnitine are transported into the mitochondrial matrix.
D、Carnitine enhances the activation of fatty acids to fatty acyl-CoA, thereby increasing the rate of their transport into the mitochondrial matrix.

12、What products from the oxidation of odd-numbered fatty acids enter the citric acid cycle?
A、acetyl-CoA and malonyl-CoA
B、acetyl-CoA and propionyl-CoA
C、acetyl-CoA and succinyl-CoA
D、succinyl-CoA and propionyl-CoA

13、In hepatocytes, what is a possible fate of acetyl-CoA produced from the oxidation of a fatty acid?
A、use in ketogenesis
B、use in gluconeogenesis
C、both oxidation via the citric acid cycle and use in ketogenesis
D、both oxidation via the citric acid cycle and use in gluconeogenesis

14、In myocytes, what is a possible fate of acetyl-CoA produced from the oxidation of a fatty acid?
A、oxidation via the citric acid cycle
B、use in ketogenesis
C、use in gluconeogenesis
D、both oxidation via the citric acid cycle and use in ketogenesis

15、Lipoprotein lipase acts in:
A、hydrolysis of triacylglycerols of plasma lipoproteins to supply fatty acids to various tissues.
B、intestinal uptake of dietary fat.
C、intracellular lipid breakdown of lipoproteins.
D、lipoprotein breakdown to supply needed amino acids.

16、Free fatty acids in the bloodstream are:
A、bound to hemoglobin.
B、carried by the protein serum albumin.
C、freely soluble in the aqueous phase of the blood.
D、nonexistent; the blood does not contain free fatty acids.

17、The glycerol produced from the hydrolysis of triacylglycerides enters glycolysis as:
A、glucose-6-phosphate.
B、dihydroxyacetone phosphate.
C、pyruvate.
D、glyceryl CoA.

18、Transport of fatty acids from the cytoplasm to the mitochondrial matrix requires:
A、ATP, carnitine, and coenzyme A.
B、ATP, carnitine, and pyruvate dehydrogenase.
C、ATP, coenzyme A, and hexokinase.
D、carnitine, coenzyme A, and hexokinase.

19、Carnitine is:
A、an essential cofactor for the citric acid cycle.
B、essential for intracellular transport of fatty acids.
C、one of the amino acids commonly found in protein.
D、present only in carnivorous animals.

20、Which compound is able to cross the inner mitochondrial membrane?
A、acetyl–CoA
B、fatty acyl–carnitine
C、fatty acyl–CoA
D、malonyl–CoA

21、What is the CORRECT order of function of the following enzymes of β-oxidation? 1. β-hydroxyacyl-CoA dehydrogenase 2. thiolase 3. enoyl-CoA hydratase 4. acyl-CoA dehydrogenase
A、1, 2, 3, 4
B、3, 1, 4, 2
C、4, 3, 1, 2
D、1, 4, 3, 2

22、Saturated fatty acids are degraded by the stepwise reactions of β-oxidation, producing acetyl-CoA. Under aerobic conditions, how many ATP molecules would be produced as a consequence of removal of each acetyl-CoA?
A、two
B、three
C、four
D、five

23、Which compound is NOT required in the synthesis of fatty acids?
A、acetyl-CoA
B、biotin
C、malonyl-CoA
D、NADH

24、Which statement is NOT true of the reaction producing malonyl-CoA during fatty acid synthesis?
A、It requires acyl carrier protein (ACP).
B、It requires CO2 (or bicarbonate).
C、One mole of ATP is converted to ADP + Pi for each malonyl-CoA synthesized.
D、The cofactor is biotin.

25、In comparing fatty acid biosynthesis with β-oxidation of fatty acids, which statement is INCORRECT?
A、A thioester derivative of crotonic acid (trans-2-butenoic acid) is an intermediate in the synthetic path, but not in the degradative path.
B、A thioester derivative of β-hydroxybutyrate is an intermediate in the synthetic path, not in the degradative path.
C、Fatty acid biosynthesis uses NADPH exclusively, whereas β-oxidation uses NAD+ exclusively.
D、Fatty acid degradation is catalyzed by cytosolic enzymes; fatty acid synthesis by mitochondrial enzymes.

26、The rate-limiting step in fatty acid synthesis is:
A、condensation of acetyl-CoA and malonyl-CoA.
B、formation of acetyl-CoA from acetate.
C、the reaction catalyzed by acetyl-CoA carboxylase.
D、formation of malonyl-CoA from malonate and coenzyme A.

27、Which compound can be synthesized by plants but NOT by humans?
A、linoleate
B、palmitate
C、phosphatidylcholine
D、stearate

28、The synthesis of both glycerophospholipids and triacylglycerols involves:
A、CDP-choline.
B、CDP-diacylglycerol.
C、phosphatidate phosphatase.
D、phosphatidic acid.

29、In the synthesis of phosphatidylcholine from phosphatidylethanolamine, the methyl group donor is:
A、a tetrahydrofolate derivative.
B、S-adenosylmethionine (adoMet).
C、methanol.
D、serine.

30、Chylomicrons carry _____ in the _____.
A、triacylglycerols; cell
B、triacylglycerols; blood
C、cholesterols; blood
D、fatty acids; blood

Homework

1、Compare the ATP yield from the complete oxidation of glucose, a six- carbon carbohydrate, and hexanoic acid, a six-carbon fatty acid. Hexanoic acid is also called caproic acid and is responsible for the “aroma” of goats. Why are fats better fuels than carbohydrates?

2、A number of genetic deficiencies in acyl CoA dehydrogenases have been described. This deficiency presents early in life after a period of fasting. Symptoms include vomiting, lethargy, and sometimes coma. Not only are blood levels of glucose low ( hypoglycemia), but starvation-induced ketosis is absent. Provide a biochemical explanation for these last two observations.

Chapter5 Metabolism of Amino Acids

quiz5

1、Which reaction associated with the urea cycle occurs in the cytosol?
A、the synthesis of carbamoyl phosphate
B、the synthesis of citrulline
C、the synthesis of arginosuccinate
D、the synthesis of both carbamoyl phosphate and citrulline

2、What enzyme classes are responsible for interconverting glutamate and α-ketoglutarate?
A、hydrolases
B、transferases
C、ligases
D、kinase

3、What processes are associated with the glucose-alanine cycle?
A、Gluconeogenesis in the liver
B、Glutamate synthesis in both muscle and the liver
C、Glucose export from the liver
D、All of the answers are correct.

4、Carbamoyl phosphate synthase I is allosterically activated by what molecule?
A、glutamate
B、arginine
C、N-acetylglutamate
D、carbamoyl phosphate

5、Conversion of ammonia to carbamoyl phosphate in mitochondria consumes how many ATP equivalents?
A、none
B、one
C、two
D、three

6、Which compound can be described as glucogenic and ketogenic?
A、leucine
B、isoleucine
C、lysine
D、alanine

7、Which amino acid is catabolized to both succinyl-CoA and acetyl-CoA?
A、leucine
B、isoleucine
C、lysine
D、valine

8、Which compound is used in single-carbon transfer reactions?
A、S-adenosyl methionine
B、tetrahydrofolate
C、biotin
D、Vitamin 6

9、Catabolism of which substance can enter the citric acid cycle as succinyl-CoA?
A、threonine
B、odd-numbered fatty acids
C、methionine
D、All of the answers are correct

10、Which amino acid enters the citric acid cycle as α-ketoglutarate during their catabolism?
A、proline
B、threonine
C、aspartate
D、leucine

11、The coenzyme required for all transaminations is derived from:
A、niacin.
B、pyridoxine (vitamin B6).
C、riboflavin.
D、thiamin.

12、The coenzyme involved in a transaminase reaction is:
A、biotin phosphate.
B、nicotinamide adenine dinucleotide phosphate (NADP+).
C、pyridoxal phosphate (PLP).
D、thiamine pyrophosphate (TPP).

13、Glutamate is metabolically converted to α-ketoglutarate and NH4+ by a process described as:
A、deamination.
B、hydrolysis.
C、oxidative deamination.
D、transamination.

14、The conversion of glutamate to an α-keto acid and NH4+:
A、does not require any cofactors.
B、is a reductive deamination.
C、is accompanied by ATP hydrolysis catalyzed by the same enzyme.
D、is catalyzed by glutamate dehydrogenase.

15、Urea synthesis in mammals takes place primarily in tissues of the:
A、brain.
B、kidney.
C、liver.
D、skeletal muscle.

16、Which substance is NOT involved in the production of urea from NH4+ via the urea cycle?
A、aspartate
B、ATP
C、carbamoyl phosphate
D、malate

17、Which substance directly donates a nitrogen atom for the formation of urea during the urea cycle?
A、adenine
B、aspartate
C、creatine
D、glutamate

18、Conversion of ornithine to citrulline is a step in the synthesis of:
A、carnitine.
B、pyruvate.
C、tyrosine.
D、urea.

19、In the urea cycle, ornithine transcarbamoylase catalyzes:
A、cleavage of urea to ammonia.
B、formation of citrulline from ornithine and another reactant.
C、formation of ornithine from citrulline and another reactant.
D、formation of urea from arginine.

20、Which statement is FALSE in reference to the mammalian synthesis of urea?
A、The precursor to one of the nitrogens of urea is aspartate.
B、The amino acid arginine is the immediate precursor to urea.
C、The carbon atom of urea is derived from mitochondrial HCO3–.
D、The process of urea production is an energy-yielding series of reactions.

21、Which amino acid is essential for humans?
A、alanine
B、threonine
C、asparagine
D、serine

22、Which amino acid can be directly converted into a citric acid cycle intermediate by transamination?
A、glutamic acid
B、serine
C、threonine
D、tyrosine

23、The human genetic disease phenylketonuria (PKU) can result from:
A、deficiency of protein in the diet.
B、inability to catabolize ketone bodies.
C、inability to convert phenylalanine to tyrosine.
D、inability to synthesize phenylalanine.

24、Which amino acids are converted to α-ketoglutarate? 1. glycine 2. glutamate 3. histidine 4. arginine 5. proline
A、1, 3, and 5
B、2, 3, and 4
C、2, 3, and 5
D、2, 3, 4, and 5

25、Which amino acids are converted to succinyl CoA? 1. isoleucine 2. valine 3. methionine 4. arginine 5. threonine
A、2 and 4
B、2, 3, and 4
C、2, 4, and 5
D、1, 2,3, and 5

Final examination

Part 1

1、The aerobic conversion of 1 mol of glucose to 2 mol of pyruvate is accompanied by a net gain of:
A、2 mol of ATP.
B、1 mol of ATP + 2 mol of NADH.
C、2 mol of ATP + 2 mol of NADH.
D、2 mol of NADH.

2、An enzyme used in both glycolysis and gluconeogenesis is:
A、aldolase.
B、glucose 6-phosphatase.
C、hexokinase.
D、pyruvate kinase.

3、Which compound is NOT required for the oxidative decarboxylation of α-ketoglutarate?
A、FAD
B、biotin
C、lipoid acid
D、CoA-SH

4、Which statement is FALSE regarding ketone bodies?
A、During prolonged starvation, the brain adapts to using ketone bodies as a fuel.
B、Excess acetone production during ketoacidosis is exhaled through the lungs.
C、Ketone bodies can be used as a carbon source for gluconeogenesis.
D、Ketone bodies are formed when the glucagon/insulin ratio is high.

5、Which protein associated with electron transport below is NOT a flavoprotein?
A、acyl-CoA dehydrogenase
B、succinate dehydrogenase
C、mitochondrial glycerol-3-phosphate dehydrogenase
D、malate dehydrogenase

6、Which statement is TRUE regarding fatty acids in adipocytes?
A、They are primarily bound to albumin and stored in lipid droplets.
B、They cannot be oxidized for energy in this tissue.
C、In adipocytes, fatty acids from the bloodstream are assembled into triglycerides by esterifying them to glycerol.
D、There is constant movement of fatty acids in and out of adipose tissues that is independent of hormone signals.

7、What is the role of lipoprotein lipase?
A、It hydrolyzes triacylglycerols of plasma lipoproteins to supply fatty acids to various tissues.
B、It aids intestinal uptake of dietary fat.
C、It initiates intracellular lipid breakdown of lipoproteins.
D、It acts to regenerate lipoprotein particles in hepatocytes.

8、Which apolipoprotein is recognized by the LDL receptor?
A、ApoB-100
B、ApoC-I
C、ApoC-II
D、ApoE

9、Carbamoyl phosphate synthase I (CPS-1) is activated by what molecule?
A、arginine
B、alanine
C、aspartate
D、glutamine

10、The reaction of the citric acid cycle that produces an ATP equivalent (in the form of GTP) by substrate level phosphorylation is the conversion of:
A、succinyl-CoA to succinate.
B、fumarate to malate.
C、succinate to fumarate.
D、malate to oxaloacetate.

11、Which amino acid is essential for humans?
A、alanine
B、serine
C、leucine
D、aspartate

12、What cofactor is required for acetyl-CoA carboxy

中国大学Biochemistry_1

Biochemistry是一门研究生命体系的化学分子组成和相互作用的学科。对于生物学、医学、化学和农业等领域都有着重要的作用。中国大学Biochemistry_1是一门探讨生命分子和反应机制的课程，目的在于让学生深入了解生命的本质。

课程概述

中国大学Biochemistry_1课程包括以下内容：

• 生物分子的结构和功能
• 酶的催化机制
• 蛋白质调控和信号转导
• 基因表达和调控
• 代谢途径和调控

通过这些内容，学生将学习到生物分子、生物化学反应和生物过程的底层机制。

课程特点

中国大学Biochemistry_1课程拥有以下特点：

1. 理论与实践相结合，探讨实际研究中的生命科学问题。
2. 涉及多个生物学领域，加深对生命科学的理解。
3. 引入前沿技术，如基因编辑技术，让学生更好地了解生命科学的未来。
4. 教师团队优秀，包括多位生命科学领域的专家和长期从事生物化学研究的教授。

教学方法

中国大学Biochemistry_1课程采用以下教学方法：

1. 在课堂上授课、讲解。教师将引入多媒体技术，通过图形、动画、模拟和实验演示等形式，生动形象地介绍生命分子的特性及其相互作用。
2. 通过学生研究论文、案例分析、小组讨论等方式，帮助学生更好地了解生物分子的功能和反应机制。
3. 开展实验教学，帮助学生掌握实验技能和操作方法。实验内容涉及分子生物学技术、酶学和基因工程等方面。

课程评价

中国大学Biochemistry_1课程评价主要通过以下几个方面：

1. 考试成绩。通过期末考试来评价学生对课程内容的掌握程度。
2. 实验报告。通过学生实验报告的撰写和评分来评价学生的实验技能和分析能力。
3. 小组讨论。通过学生小组讨论的活跃程度和掌握程度，来评价学生对生物分子和反应机制的理解程度。

结语

中国大学Biochemistry_1课程是一门探讨生命分子和反应机制的课程，通过理论和实践相结合的教学方法，让学生深入了解生命的本质，并为未来在生命科学领域的研究奠定基础。