Respiration

Question 1

What are the two types of Respiration and state the difference?

Answer 1

Aerobic Respiration (Oxygen)

Anaerobic Respiration (No Oxygen)

Question 2

Name the 4 stages of Aerobic Respiration and where they take place

Answer 2

Glycolysis (Cytoplasm)
Link Reaction
Krebs Cycle
Oxidative Phosphorylation

(Inside Mitochondria)

Question 3

Explain what happens during Glycolysis

Answer 3

• Splits one molecule of glucose (6 Carbon) into 2 pyruvate molecules (3 Carbon)
• Occurs in the Cytoplasm
• Anaerobic process as it does not require oxygen

Question 4

What are the products of Glycolysis? Draw the diagram

Answer 4

2x ATP Molecules
2x NADH
2x Pyruvate

Question 5

Explain what happens during Link Reaction

Answer 5

• Converts 2 Pyruvate (3C) into Acetyl Coenzyme A (2C)
• Occurs twice due to 2 pyruvate molecule
• Takes place in matrix of mitochondria
• No ATP produced

Question 6

What are the products of the Link Reaction? Draw the Diagram

Answer 6

For every glucose molecule:

• 2x Acetyl Coenzyme A transported to the Krebs Cycle
• 2x Carbon Dioxide Molecules are released as waste
• 2x Reduced NAD - These go to Oxidative Phosphorylation

Question 7

Explain what happens during the Krebs Cycle

Answer 7

• Series of oxidation-reduction reactions to produce reduced coenzymes and ATP
• Happens in the matrix of mitochondria
• Happens twice for every GLUCOSE molecule

Question 8

What are the products of the Krebs Cycle? Draw the Diagram

Answer 8

DENA, DENA, A, FA, NA

• Decarboxylation of NADH
• Decarboxylation of NADH
• Production of ATP
• Production of reduced FAD
• Production of NAD

PRODUCTS:
- 1x Coenzyme A
- 1x Oxaloacetate (4C)
- 2x CO2 moleucles
- 3x NADH
- 1x FADH
- 1x ATP

Question 9

Explain what happens during Oxidative Phosphorylation

Answer 9

Final stage of respiration

Energy carried by electrons from reduced Coenzymes (NADH & FADH) used to make ATP

Involves ETC and Chemiosmosis

Happens across inner mitochondrial membrane

Question 10

What are the products of Oxidative Phosphorylation

Answer 10

• High concentration of H+ in intermembrane space compared to that in matrix
• Forms electrochemical gradient
• Protons move down electrochemical gradient back into matrix via ATP Synthase

Question 11

Describe Anaerobic Reaction

Answer 11

Happens without presence of Oxygen.

Only small amount of ATP produced

Products differ between plants and animals

_________________________

Krebs Cycle and Oxidative Phosphorylation cannot take place without oxygen

Question 12

In the absence of oxygen, Pyruvate can follow two pathways which are:

Answer 12

• Alcoholic Fermentation: in plants and yeasts respiring anaerobically
• Lactate (Lactic Acid) fermentation: in animals respiring anaerobically