Respiration

Question 1

stages of respiration (4)

Answer 1

1) glycolysis
2) link reaction
3) krebbs cycle
4) electron transport chain

Question 2

where does glycolysis occur?

Answer 2

cytoplasm

Question 3

net products of glycolysis

Answer 3

• 2 ATP
• 2 pyruvate
• 2 NADH

Question 4

where does link reaction occur?

Answer 4

matrix

Question 5

products of the link reaction

Answer 5

2 acetyl co-enzyme A
2 NADH
2 CO2

Question 6

where does krebbs cycle occur?

Answer 6

matrix

Question 7

products of krebbs cycle

Answer 7

• 6 NADH

- 2 FADH

Question 8

where does electron transport chain occur?

Answer 8

cristae

Question 9

overall products of first 3 stages

Answer 9

10 x NADH

2 x FADH

Question 10

anaerobic respiration

Answer 10

when O2 is NOT final electron acceptor

Question 11

oxygen debt

Answer 11

amount of oxygen required to convert lactic acid to CO2 and H2O

Question 12

stages of anaerobic respiration in plants and yeast

Answer 12

glucose -> pyruvate —[CO2 produced]–> ethanal –[NAD produced]–> ethanal + CO2

Question 13

stages of anaerobic respiration in animals

Answer 13

glucose -> pyruvate (reduced) –[ NAD produced]–> lactic acid

Question 14

co enzyme

Answer 14

molecules which some enzymes require in order to function

Question 15

role of co enzymes in respiration

Answer 15

carry H atoms from one molecule to another

Question 16

co enzyme eg. (3)

Answer 16

• NAD
• FAD
• NADP - (photosynthesis)

Question 17

significance of Krebs cycle (4)

Answer 17

• breaks down big molecules into smaller ones - pyruvate into CO2
• produces H atoms which are carried by co enzymes to electron transport chain - leading to production of ATP which produces metabolic energy for the cell
• regenerates 4C molecule which combines with acetyl coenzyme a which would otherwise accumulate
• source of intermediate compounds used by cells in the manufacture of other important compounds eg. chlorophyll + fatty acids

Question 18

role of oxygen in respiration

Answer 18

final hydrogen acceptor - removes H atoms at end of the chain so that H+ and e- dont back up the chain

Question 19

why does anaerobic respiration produce less ATP than aerobic?

Answer 19

relies on substrate level phosphorylation - only 2 atp from glycolysis
many more from Krebs and link and ETC - oxidative phosphorylation

Question 20

What substance is converted to ethanol under anaerobic conditions in ethanol fermentation?

Answer 20

pyruvate

Question 21

What enzyme catalyses the reaction in which pyruvate is reduced to lactate?

Answer 21

lactate dehydrogenase

Question 22

What is the name of the process in which protons diffuse down the concentration gradient through the ATP synthase enzyme, creating ATP in oxidative phosphorylation?

Answer 22

chemiosmosis

Question 23

What processes are applied to the six-carbon molecule citrate, to convert it to a five-carbon molecule in the Krebs cycle?

Answer 23

• decarboxylation

- dehydrogenation

Question 24

what makes ATP suitable as a source of energy (3)?

Answer 24

• relatively small amount of energy produced
• can be resynthesises rapidly
• releases energy instantly