Cell Respiration Objective Type Questions and Answers

21 The overall goal of glycolysis, Krebs cycle and the electron transport system is the formation of

A ATP in one large oxidation reaction

B sugars

C nucleic acids

D ATP in small stepwise units

Answer: ATP in small stepwise units

22 All enzymes of TCA cycle are located in the mitochondrial matrix except one which is located in inner mitochondrial membranes in eukaryotes and in cytosol in prokaryotes. This enzyme is

A isocitrate dehydrogenase

B malate dehydrogenase

C succinate dehydrogenase

D lactate dehydrogenase

View Answer

Answer: succinate dehydrogenase

23 How many ATP molecules could maximally be generated from one molecule of glucose, if the complete oxidation of one mole of glucose to C02 and H20 yields 686 kcal and the useful chemical energy available in the high energy phosphate bond of one mole of ATP is 12 kcal?

A 1

B 2

C 30

D 57

View Answer

Answer: 57

24 During which stage in the complete oxidation of glucose are the greatest number of ATP molecules formed from ADP?

A glycolysis

B Kreb’s cycle

C conversion of pyruvic acid to acetyl CoA

D electron transport chain

View Answer

Answer: electron transport chain

25 In glycolysis, during oxidation electrons are removed by

A ATP

B glyceraldehyde-3-phosphate

C NAD+

D molecular oxygen

View Answer

Answer: NAD+

26 In alcohol fermentation

A triose phosphate is the electron donor while acetaldehyde is the electron accept

B triose phosphate is the electron donor while pyruvic acid is the electron acceptor

C there is no electron donor

D oxygen is the electron acceptor

View Answer

Answer: triose phosphate is the electron donor while acetaldehyde is the electron accept

27 In which one of the following do the two names refer to one and the same thing?

A Krebs cycle and Calvin cycle

B tricarboxylic acid cycle and citric acid cycle

C citric acid cycle and Calvin cycle

D tricarboxylic acid cycle and urea cycle

View Answer

Answer: tricarboxylic acid cycle and citric acid cycle

28 How many ATP molecules are produced by aerobic oxidation of one molecule of glucose?

A 2

B 4

C 38

D None of these

View Answer

Answer: 38

29 Organisms which obtain energy by the oxidation of reduced inorganic compounds are called

A photoautotrophs

B chemoautotrophs

C saprozoic

D coproheterotrophs

View Answer

Answer: chemoautotrophs

30 Net gain of ATP molecules, during aerobic respiration, is

A 40 molecules

B 48 molecules

C 36 molecules

D 38 molecules

View Answer

Answer: 36 molecules

31 Which of the following is the key intermediate compound linking glycolysis to the Krebs’ cycle?

A malic acid

B acetyl CoA

C NADH

D None of these

View Answer

Answer: acetyl CoA

32 In Krebs’ cycle, the FAD precipitates as electron acceptor during the conversion of

A fumaric acid to malic acid

B succinic acid to fumaric acid

C succinyl CoA to succinic acid

D a-ketoglutarate to succinyl CoA.

View Answer

Answer: succinic acid to fumaric acid

33 The end products of fermentation are

A O2 and C2H5OH

B CO2 and acetaldehyde

C CO2 and O2

D CO2 and C2H5OH

View Answer

Answer: CO2 and C2H5OH

34 Which of the following products are obtained by anaerobic respiration from yeast?

A beer and wine

B alcohols

C CO2

D all of these

View Answer

Answer: all of these

35 At the end of glycolysis, six carbon compounds ultimately changes into

A ethyl alcohol

B acetyl Co-A

C pyruvic acid

D ATP

View Answer

Answer: pyruvic acid

36 When one molecule of ATP is disintegrated, what amount of energy is liberated?

A 8 kcal

B 38 kcal

C 7 kcal

D 4.5 kcal

View Answer

Answer: 7 kcal

37 Poisons like cyanide inhibit Na+ efflux and K+ influx during cellular transport. This inhibitory effect is reversed by an injection of ATP. This demonstrates that

A ATP is the carrier protein in the transport system

B energy for Na+-K+ exchange pump comes from ATP

C ATP is hydrolysed by ATPase to release energy

D Na+-K+ exchange pump operates in the cell.

View Answer