Respiration

Question 1

What does respiration do?

Answer 1

Makes energy available for movement, growth, reproduction and repair

Question 2

What does aerobic respiration produce?

Answer 2

Lots of ATP

Question 3

What does anaerobic respiration prodcue?

Answer 3

Little ATP

Question 4

Name the two structural features of mitochondria

Answer 4

Cristae
Matrix

Question 5

What is the equation for aerobic respiration?

Answer 5

Glucose + Oxygen = Carbon dioxide + water

Question 6

Name the 4 stages of aerobic respiration

Answer 6

1. Glycolysis
2. Link reaction
3. Krebs cycle
4. Electron transport cycle

Question 7

Name the 2 stages of anaerobic respiration

Answer 7

1. Glycolysis
2. Link reaction

Question 8

What happens during glycolysis?

Answer 8

STAGE 1 - Phosphorylation
1) Glucose is phosphorylated using a phosphate from a molecule of ATP. This creates 1 molecule of glucose phosphate and 1 molecule of ADP
2) ATP is then used to add another phosphate forming hexose biphosphate. This is then split into 2 molecules of triose phosphate
STAGE 2 - OXIDATION
1) TP is oxidised forming 2 molecules of pyruvate
2) NAD collects the hydrogen ions, forming 2 reduced NAD.
3) 4 ATP are produced but there is a net gain of 2 ATP

Question 9

What happens in glycolysis (aerobic respiration)?

Answer 9

The two molecules of reduced NAD go to oxidative phosphorylation
The two pyruvate molecules are actively transported into the matrix of mitochondria for the link reaction

Question 10

In aerobic respiration what is pyruvate converted into?

Answer 10

Plants & yeasts (alcoholic fermentation) - converted into ethanol
Animals (lactate fermentation) - converted into lactate

Question 11

Describe what happens in the link reaction

Answer 11

(Oxygen is present and happens in the matrix)
1. Pyruvate is decarboxylated
2. Pyruvate is oxidised to form acetate
3. NAD is reduced to form reduced NAP
4. Acetate is combined with coenzyme A to form acetyl coenzyme A
4. No ATP is produced

Question 12

Where do the products of the link reaction go to?

Answer 12

2 molecules of acetyl CoA = Krebs cycle
2 molecules of carbon dioxide = waste products of respiration
2 molecules of NADH = oxidative phosphorylation

Question 13

Explain what happens during the Krebs cycle

Answer 13

1. Acetyl CoA combines with oxaloacetate (4C) to form citrate (6C). Coenzyme A goes back to the link reaction
2. 6C citrate is converted to a 5C molecule. Decarboxylation ann dehydrogenation occur. Hydrogen is used to produce NADH from NAD
3. 5C molecule is converted to a 4C molecule. Decarboxylation and dehydrogenation occur to produce 1 FADH & 2 NADH. ATP is produced

Question 14

Explain what happens during the Electron Transport Chain (oxidation phosphorylation)

Answer 14

1. Hydrogen is release from NADH and FADH (oxidisation). The H atoms split into protons and electrons
2. Electrons move down the electron transport losing energy. Energy is the used by electron carriers to pump protons from matrix into intermembrane space
3. Concentration of protons is higher in the intermembrane space than in the matrix (electrochemical gradient)
4. Protons move down the electrochemical gradient back into the matrix via ATP synthase. Movement drives the synthesis of ATP
5. Process of ATP production is drive by the movement of protons across a membrane is called chemiosmosis
6. At the end of the transport in the matrix protons, electrons and oxygen combine to form water

Question 15

What are mitochondrial diseases and what do they affect?

Answer 15

Affect functioning of mitochondria
Affect how proteins involves in oxidative phosphorylation or Krebs cycle function.

Question 16

What occurs due to mitochondrial disease?

Answer 16

ATP production reduces
Anaerobic respiration increases