Metabolic Processes - Regulation of Cellular Respiration + Anaerobic Pathways

Question 1

Metabolic rate vs basal metabolic rate

Answer 1

Metabolic rate: the amount of energy a living thing is using over a given period of time
Basal metabolic rate: the metabolic rate of a living thing when it is at rest (60-70% of energy needs per day)

Question 2

What is allosteric control?

Answer 2

• A way of activating or inhibiting an enzyme by the molecule binding to a specific site (allosteric site) on the enzyme which changes its conformation + activity
• An inhibitor changes the shape of the active site so that it is unable to bond the substrate
• An activator changes the shape of the active site so that it can bond the substrate

Question 3

How is phosphofructokinase regulated to control cellular respiration?

Answer 3

• Controls flow of glucose into glycolysis
• Activated by: low levels of citrate, high levels of ADP
• Inhibited by: high levels of ATP and NADH

Question 4

How is pyruvate decarboxylase regulated to control cellular respiration?

Answer 4

• Control production of Acetyl-CoA from pyruvate (pyruvate oxidation)
• Inhibited by: high levels of NADH

Question 5

What is the difference between anaerobic respiration and fermentation?

Answer 5

• Anaerobic respiration uses an ETC with an inorganic substance as the final electron acceptor
• Fermentation uses an organic molecule as the final electron acceptor and does not use an ETC (not a form of respiration)

Question 6

Why is fermentation necessary for glycolysis to continue in anaerobic organisms?

Answer 6

Fermentation allows for pyruvate to be removed and for NAD+ to be regenerated, which allows for glycolysis to continue

Question 7

What are the two types of fermentation and the reactants + products of each?

Answer 7

1. Lactate fermentation: pyruvate + NADH + a proton -> lactate + NAD+
2. Alcoholic fermentation: pyruvate -> alcohol + CO2 + NAD+