Basics of metabolism

Question 1

what is catabolism in metabolism?

Answer 1

degradation of nutrients to salvage their components and/or generate energy

Question 2

What is anabolism in metabolism?

Answer 2

biosynthesis of new molecules from simpler components

Question 3

Describe the intrinsic regulation of metabolism

Answer 3

Reactions which self-regulate to respond to changes in the levels of substrate or products

Question 4

Describe extrinsic control of metabolism?

Answer 4

a cell changing its metabolism in response to signals from other cells

Question 5

Describe the basic reactions that produce energy

Answer 5

Energy comes from breakdown of glucose, fatty acids and amino acids into acetyl CoA
Acetyl CoA enters the Krebs cycle to produce energy in 2 ways:
- as ATP (substrate-level phosphorylation)
- through NADH/FADH2 which is processed through oxidative phosphorylation to produce more ATP

Question 6

Describe the ATP-ADP cycle

Answer 6

as body functions use up energy ATP is converted to ADP and an inorganic phosphate
ADP and inorganic phosphate are used to create ATP for energy

Question 7

What are the 2 key aspects of metabolism?

Answer 7

Krebs cycle
Oxidative phosphorylation

Question 8

Describe the Krebs/TCA/citric acid cycle

Answer 8

Acetyl CoA (precursor to cycle) is produced from AAs, fatty acids and glucose
Series of reactions that oxidise Acetyl CoA to CO2
Electrons lost from these reactions are used in oxidative phosphorylation to produce ATP
Some steps release energy that is directly captured as ATP (substrate level-phosphorylation)

Question 9

Describe the process of oxidative phosphorylation

Answer 9

Electrons from the Krebs cycle are transferred into the electron transport chain in mitochondrion via an electron carrier
As electrons pass down the electron transport chain it releases energy which is used to pump protons out of the mitochondrion forming an electrochemical gradient
when protons flow back down their gradient they pass through ATP synthase (enzyme) => ATP synthesis
Electrons eventually join O2 to form water

Question 10

what is resting metabolic rate (RMR)/ basal metabolic rate (BMR)?

Answer 10

energy required to maintain life

Question 11

What factors affect BMR?

Answer 11

size
age
sex
species
body temp
ambient temp
thyroid hormone secretion
pregnancy and lactation
growing animals
genetic factors

Question 12

How many testicles do zebras have

Answer 12

3 or 4

although some have 1 gigantic testicle the size of Jorges forehead