RESPIRATION

Question 1

Write a brief note on glycolysis.

Answer 1

• First stage of respiration
• The breakdown of glucose (6C) into two pyruvates (2 x 3C) in the cytosol.
• Oxygen is not needed
• A small amount of energy is used - 2 ATP
• Some energy is used to make NADH.

Question 2

Write a brief note on Acetyl Co - Enzyme A.

Answer 2

• Pyruvic acid loses a carbon dioxide molecule
• Forms a 2-carbon molecule called acetyl coenzyme A.

Question 3

Write a brief note on Adenosine triphosphate.

Answer 3

• ATP is an energy courier as it diffuses rapidly.
• It is an energy carrier
• It stores chemical energy

Question 4

Write a brief note on the electron transport chain.

Answer 4

• Oxygen is required
• ## The electrons are passed along a series of carrier molecules.

Question 5

Name the 3-carbon molecule that is an intermediate compound in both aerobic and anaerobic
respiration.

Answer 5

Pyruvate

Question 6

What name is given to the biochemical pathway by which this intermediate compound is
produced?

Answer 6

Glycolysis

Question 7

What happens to the intermediate compound referred to in (i) above when oxygen is available
and used in the breakdown of glucose?
In your answer refer to:
1. Krebs cycle.
2. Electron transport system.

Answer 7

• It enters the lumen of the mitochondrion
• It loses CO2 and 2H + and 2e-
• It gets converted to acetyl coenzyme A.
• NADH is formed and enters the electron transport system.
• Electrons are passed along a series of carrier molecules
• Energy is released
• ATP is made from ADP and P.

Question 8

What is produced from the intermediate compound referred to in (i) above when oxygen is not
available
1. in muscle?
2. in yeast?

Answer 8

1. Lactic Acid
2. Ethanol

Question 9

Name two types of particle that are transferred by NAD.

Answer 9

Electrons and protons.

Question 10

How constant pH maintained:

Answer 10

pH buffer

Question 11

How constant temperature maintained:

Answer 11

Water bath

Question 12

Other product produced during fermentation:

Answer 12

CO2

Question 13

Test to confirm alcohol present:

Answer 13

Iodoform (test)

Question 14

Balanced equation to summarise aerobic respiration

Answer 14

C6H12O6 + 6O2  6H2O + 6CO2

Question 15

Name the storage polysaccharide in humans from which glucose is produced.

Answer 15

Glycogen

Question 16

Give one major storage location of this polysaccharide in the body.

Answer 16

Liver

Question 17

What happens to pyruvate molecules that prepares them for the Krebs cycle?

Answer 17

Lose a carbon atom.

Question 18

Name three products of the Krebs cycle.

Answer 18

ATP/ CO2/ NADH

Question 19

Fate of ATP

Answer 19

used in active transport

Question 20

Fate of CO2

Answer 20

used in photosynthesis

Question 21

Fate of NADH

Answer 21

releases electrons

Question 22

Final electron acceptor in aerobic respiration:

Answer 22

Oxygen

Question 23

Does fermentation need oxygen:

Answer 23

No

Question 24

Location of fermentation in cell:

Answer 24

Cytosol

Question 25

Which substance alcohol made from

Answer 25

Glucose

Question 26

Optimum temperature:

Answer 26

20 - 35

Question 27

Positive colour:

Answer 27

Yellow

Question 28

How know fermentation finished:

Answer 28

No more bubbles.

Question 29

Name the series of chemical reactions, involving acetyl Co. A, which does occur in the mitochondrion.

Answer 29

Krebs' cycle

Question 30

State the number of carbon atoms in a molecule of acetyl co-enzyme A.

Answer 30

2

Question 31

Sometimes lactic acid is produced during respiration. Describe a condition during which this may occur.

Answer 31

Anaerobic conditions.

Question 32

Anaerobic respiration occurs in

Answer 32

Only one stage - glycolysis

Question 33

Aerobic respiration occurs in

Answer 33

2 stages - Kreb Cycle and Glycolysis