Respiration

Question 1

What are the 4 stages of aerobic respiration?

Answer 1

1. Glycolysis
2. Link reaction
3. Krebs cycle
4. Oxidative phosphorylation

Question 2

Where does glycolysis take place

Answer 2

In the cytoplasm

Question 3

Where does the link reaction take place?

Answer 3

In the matrix

Question 4

Where does the Krebs cycle take place?

Answer 4

In the matrix (mitochondria)

Question 5

Where does oxidative phosphorylation take place ?

Answer 5

In the inter membrane space / across the cristae/ across the inner membrane

Question 6

What is glycolysis ?

Answer 6

Breaking down glucose into pyruvate whilst producing ATP and harvesting protons (H+) and electrons (e-) along the way.

Question 7

What is the process of glycolysis ?

Answer 7

1. Glucose is phosphorylated into glucose phosphate using 2x ATP
2. Glucose phosphate breaks down into 2x triose phosphate
3. 2x triose phosphate are oxidised into 2x pyruvate using 2x NAD+
4. This forms 2x NADH and 4x ATP
5. This occurs in the cytoplasm

Question 8

What are the products of glycolysis?

Answer 8

2x NADH
2x pyruvate (3c)

Question 9

How does pyruvate enter the matrix?

Answer 9

Via active transport crossing the double membrane

Question 10

What is the process of the link reaction?

Answer 10

• oxidation of a pyruvate with NAD to remove hydrogen ion (protons) and release co2
• addition of coenzyme A to produce acetylCOA

Question 11

Why does CO2 get released in the link reaction?

Answer 11

When the enzyme removed a proton or electron from the pyruvate (3c) it makes it unstable which leads to a loss of carbon with two molecules of oxygen attached (CO2)

Question 12

What is the process of the Krebs cycle ?

Answer 12

1. AcetylCOA(2c) is combined with a 4 carbon molecule to form a 6c molecule.
   2.the 6c molecule is oxidised into a 5c molecule using NAD+.decarboxylation occurs.
   3.the 5c molecule is oxidised into a 4c molecule using FAD+. Decarboxylation occurs.
2. ATP is also generated