Cellular Respiration

Question 1

What happens in anaerobic respiration?

Answer 1

Conversion of ethanol to lactate or CO2+ethanol

Question 2

Name the products of glycolysis

Answer 2

4 ATP (net gain of 2), 2 NADH + H+, 2 pyruvate

Question 3

What happens in the link reaction?

Answer 3

Pyruvate decarboxylated to acetyl, then converted to acetyl CoA

Question 4

How many steps are in the Krebs cycle?

Answer 4

5 steps (6 -> 5 -> 4 -> 4 -> 4-> 4-> addition of acetyl CoA)

Question 5

What is chemiosmosis?

Answer 5

Coupling of exergonic reactions of the Electron Transport Chain and ATP synthase

Question 6

What is the order of processes in aerobic cellular respiration?

Answer 6

Glycolysis, link reaction, Krebs cycle, oxidative phosphorylation

Question 7

Define cellular respiration

Answer 7

The controlled release of energy from organic compounds in cells to form ATP

Question 8

Write a balanced equation for aerobic respiration

Answer 8

C6H12O6 + 6O2 –> 6CO2 + 6H2O + energy

Question 9

What are the differences between aerobic and anaerobic respiration?

Answer 9

• Aerobic requires oxygen
• Aerobic takes place in mitochondria, anaerobic in muscles
• Aerobic more efficient and generates 19x more energy (38 ATP) due to complete breakdown of glucose, anaerobic useful for a sudden burst of energy or when oxygen-deficient
• End products vary: aerobic CO2 and H2O, anaerobic lactic acid in humans/CO2+ethanol in plants (toxic in excess)

Question 10

What is the energy generated from respiration used for?

Answer 10

3 types of activity:

• synthesis of large molecules e.g. nucleic acids, proteins
• active transport (transmembrane) of molecules and ions
• moving things inside cells

Question 11

What can be used for respiration, aside of glucose?

Answer 11

Other carbohydrates and lipids in plants and humans, sometimes even amino acids in humans

Question 12

Outline the process of respiration

Answer 12

Organic molecules broken down in enzyme-catalysed controlled reactions, packaging of energy released from breaking of covalent bonds into ATP

Question 13

Describe the structure of ATP and ADP

Answer 13

ATP: Ribose sugar with 3 phosphate groups on C4, and adenine on C1
ADP: 2 phosphate groups instead

Question 14

What does ATP stand for?

Answer 14

Adenosine triphosphate

Question 15

What does NAD stand for?

Answer 15

Nicotinamide adenine dinucleotide

Question 16

Why is ATP referred to as the “universal energy currency”?

Answer 16

All living cells use it to store energy, as turnover from converting ADP + Pi –> ATP is high
Not transferred from cell to cell, so continuous supply required