Paper 1: Respiration

Question 1

How does cellular respiration compare to combustion?

Answer 1

1. Both processes need fuel
2. Both need oxygen
3. Both processes release carbon dioxide and water as waste products
4. Both processes release energy

Question 2

ATP formula

Answer 2

ATP - P —> ADP or ADP + P —> ATP

Question 3

Anaerobic respiration steps

Answer 3

1. Glycolysis in the cyctoplasm
2. Forming of Acetyl Co-enzyme A
3. Krebs cycle
4. Hydrogen transfer system

Question 4

1. Glycolysis in the cyctoplasm

Answer 4

1. Glycolysis:
   - Glucose is broken down into 2 molecules of pyruvic acid
   - 2 ATP are produced
   - hydrogens are removed and bind temporarily with the hydrogen carrier, NAD.
   - does not need oxygen

Question 5

Forming of Acetyl Co- enzyme A

Answer 5

• A CO2 is removed and released

- although oxygen is not involved in this process either, it will not share without sufficient oxygen available

Question 6

Krebs cycle

Answer 6

• This process occurs in the mitochondria
• CO2 is released
• Energy rich hydrogen is released and bind with NAD
• 2 ATPs are produced
• Glucose is now broken down fully

Question 7

Hydrogen transfer system

Answer 7

• this process occurs in the mitochondrion

- the energy of the hydrogens is removed step by step to form ATP

Question 8

Anaerobic respiration

Answer 8

Respiration in the absence of oxygen can occur in plants as well as animal cells. Many unicellular organisms can respirate anaerobically. Anaerobic respiration also uses glucose as fuel but it delivers much less energy per reaction.

Question 9

Lactic acid fermentation

Answer 9

When muscle cells experience an oxygen deficiency