AEROBIC RESPIRATION

Question 1

What are the stages of aerobic respiration? (4)

Answer 1

-glycolysis
-link reaction
-krebs cycle
-oxidative phosphorylation

Question 2

what is aerobic respiration? (1)

Answer 2

the chemical breakdown of substrate molecules in cells to release energy in the form of ATP when oxygen is present.

Question 3

what does aerobic respiration involve? (1)

Answer 3

it involves splitting of glucose to produce carbon dioxide and water in the presence of oxygen.

Question 4

explain what occurs during glycolysis. (2)

Answer 4

in this process glucose is phosphorylated to produce 2 molecules pyruvate, 2 molecules of ATP and 2 molecules of NADH.

Question 5

explain what occurs during the link reaction? (1)

Answer 5

where pyruvate is converted into acetyl coenzyme in with the help of NADH.
-acetyl coA then enters the krebs cycle where glucose is oxidised and carbon dioxide, ATP are reduced and FAD is produced.

Question 6

where do the link reaction and krebs cycle occur? (1)

Answer 6

in the mitochondrial matrix

Question 7

where does glycolysis occur? (1)

Answer 7

occurs in the cytoplasm

Question 8

what occurs in oxidative phosphorylation? (1)

Answer 8

the process in which ATP is synthesised via chemiosmosis in the electron transport chain of mitochondria, this process generates the majority of ATP in aerobic respiration.

Question 9

what is the first stage of oxidative phosphorylation? (1)

Answer 9

reduced co-enzymes NADH2 and FADH2 carry hydrogen ions and electrons to the electron transport chain which occurs on the inner mitochondrial membrane

Question 10

what is the second stage of oxidative phosphorylation? (1)

Answer 10

electrons are carried from one electron carrier to another in a series of redox reactions, the electron carrier which passes the electron on is oxidised whereas the electron carrier which receives it is reduced.

Question 11

what is the third stage of oxidative phosphorylation? (1)

Answer 11

hydrogen ions move across the membrane into the intermembrane space - as a result of that the concentration of the hydrogen ions in the intermembrane space increases.

Question 12

what is the fourth stage of oxidative phosphorylation? (1)

Answer 12

hydrogen ions diffuse back into the mitochondrial matrix down their electrochemical and concentration gradients

Question 13

what is the fifth stage of oxidative phosphorylation? (1)

Answer 13

ATP is produced on stalked particles using ATP synthase.

Question 14

what is the sixth stage of oxidative phosphorylation? (1)

Answer 14

hydrogen atoms are produced from hydrogen ions and electrons. The hydrogen atoms are then combined with oxygen to produce water.

Question 15

what are the stages of glycolysis? (5)

Answer 15

-phosphorylation
-lysis
-oxidation
-dephosphorylation
-production of pyruvate

Question 16

what occurs during phosphorylation of glycolysis? (1)

Answer 16

glycose (6c) is phosphorylated by ZATP to form fructose biophosphate (6c)

Question 17

what is the chemical reaction of the phosphorylation of glycolysis? (1)

Answer 17

glucose + 2ATP – fructose biophosphate

Question 18

what occurs during lysis of glycolysis? (1)

Answer 18

fructose biophosphate (6c) splits into two molecules of triose phosphate (3c)

Question 19

what is the chemical reaction of the lysis of glycolysis? (1)

Answer 19

fructose biophosphate – 2 triose phosphate

Question 20

what occurs during oxidation of glycolysis? (1)

Answer 20

hydrogen is removed from each molecule of triose phosphate and transferred to co-enzyme NAD to form 2 reduced NAD

Question 21

what is the chemical reaction of the oxidation of glycolysis? (1)

Answer 21

4H + 2NAD – 2NADH + 2H+

Question 22

what occurs during dephosphorylation of glycolysis? (1)

Answer 22

phosphates are transferred from the intermediate substrate molecules to form ATP through substrate-linked phosphorylation

Question 23

what is the chemical reaction of the dephosphorylation of glycolysis? (1)

Answer 23

4Pi + 4ADP – 4ATP

Question 24

what occurs during production of pyruvate of glycolysis? (1)

Answer 24

pyruvate is produced the end produce of glycolysis which can be used in the next stage of respiration.

Question 25

what is the chemical reaction of the production of pyruvate of glycolysis? (1)

Answer 25

2 triose phosphate – 2 pyruvate

Question 26

what is the krebs cycle? (5)

Answer 26

acetyl coA – coA is released and acetyl is converted into citrate (6c)
citrate – 5c compound
5c compound – 4c compound
4c compound (undergoes many intermediate reaction) – produces ATP, FADH2 and NADH
NADH – produces oxaloacetate

Question 27

what does the krebs cycle generate? (4)

Answer 27

2 x CO2 produced by decarboxylation
6 x NADH produced by redox reactions
2 x FADH2 produced by redox reactions
2 x ATP produced by substrate phosphorylation

Question 28

what is the formula for respiration? (1)

Answer 28

glucose + oxygen – carbon dioxide + water + energy

Question 29

what occurs during oxidative phosphorylation? (3)

Answer 29

the hydrogen atoms (or their electrons) are transported along a series of carriers, from the reduced NAD (or FAD) to be combined with oxygen to form water.
The energy transferred to ADP and Pi forming ATP.

Question 30

what is the role of oxygen in oxidative phosphorylation? (1)

Answer 30

the role of oxygen in this process is that of the final hydrogen acceptor.

Question 31

what is the total yield from aerobic respiration of ATP? (1)

Answer 31

about 38 ATPS per molecule of glucose respired.

Question 32

what is chemiosmosis? (1)

Answer 32

the process by which the movement of protons across the inner mitochondrial membrane is coupled to the synthesis of ATP.

Question 33

what is ATP synthase? (1)

Answer 33

an enzyme found in the inner mitochondrial membrane, which channels hydrogen ions through the membrane during ATP synthesis by chemiosmosis.