Metabolism

Question 1

What is metabolism?

Answer 1

The process which living systems acquire and use free energy in order to carry out their functions

Question 2

What does anabolic mean?

Answer 2

The synthesis of biomolecules from simpler components

Question 3

What does catabolic mean?

Answer 3

The degradation of nutrients to salvage components and gain energy

Question 4

What are the 2 key principles that govern metabolism?

Answer 4

Common evolutionary origin

Laws of thermodynamics

Question 5

What is an autotroph?

Answer 5

Autotrophs synthesise all cellular components from simple molecules

Question 6

What is a photoautotroph?

Answer 6

Photoautotrophs use light to produce carbohydrates which are oxidised giving free energy

Question 7

What are chemolithotrophs?

Answer 7

Chemolitrophs obtain free energy from inorganic compound oxidation

Question 8

What is a heterotroph?

Answer 8

A heterotroph oxides carbs, lipids and proteins

Question 9

What is the main oxidising agent?

Answer 9

O2

Question 10

How do we obtain vitamins?

Answer 10

Diet

Question 11

What are the 2 types of pathways ?

Answer 11

Degradative pathways

Biosynthetic pathways

Question 12

What is a -ve ∆G, +ve ∆G and 0 ∆G ?

Answer 12

-ve ∆G = Favourable
0 ∆G = Equilibrium
+ve ∆G = unfavourable (needs ATP input)

Question 13

What is ∆G?

Answer 13

Free energy

Question 14

What do all reactions use to increase speed?

Answer 14

Enzymes

Question 15

Where can metabolic reactions occur? (8)

Answer 15

Cytosol
RER
SER
Mitchondrion - matrix
Nucleus
Peroxisome
Lysosome
Golgi apparatus

Question 16

What are the 4 types of carb metabolism?

Answer 16

Glycolysis (glucose breakdown)
Gluconeogenesis (Synthesis of glucose)
Glycogen breakdown, glycogen synthesis
Pentose phosphate pathway

Question 17

What are the 2 types of fat metabolism?

Answer 17

Synthesis of free fatty acids

Mobilization of TAGs and breakdown of FFA

Question 18

What are the 2 Amino acid metabolism processes?

Answer 18

Removal of amino group to from NH4+

Urea cycle

Question 19

What is a metabolic role of the liver?

Answer 19

Metabolism of carbs, lipid and A.A

Question 20

What is a metabolic role of the muscle? (2)

Answer 20

ATP production for muscle contraction

Source of A.A. in short-term starvation

Question 21

What is a metabolic role of the brain?

Answer 21

Nerve transmission - high ATP requirement

Question 22

What is a metabolic role of adipose?

Answer 22

Fat synthesis and storage

Question 23

What drives ATP synthesis?

Answer 23

Proton gradient

Question 24

Where is the electron transport chain found?

Answer 24

Inner mitochondrial membrane

Question 25

What are the 2 mobile electron carriers in the ETC?

Answer 25

Coenzyme Q and cytochrome C

Question 26

What happens at complex 1 of the ETC?

Answer 26

NADH binds and transfers electrons to Q

Question 27

What happens at complex 2 of the ETC? (2)

Answer 27

Accepts electrons from FADH

Transfers electrons to Q

Question 28

What is coenzyme Q?

Answer 28

Small lipid compound that transfers electrons

Question 29

What happens at complex 4 of the ETC? (2)

Answer 29

8 electrons pumped across IMM

Water molecule produced

Question 30

Why transfer electrons?

Answer 30

Protons pumping across the IMM creates a proton gradient - drives ATP synthesis

Question 31

What is ATP synthase?

Answer 31

Rotates as protons pass down the channel - conformational change of ADP to ATP

Question 32

Why does our body not just use glycolysis?

Answer 32

Oxidative phosphorylation is much more efficient

Question 33

What are 3 inhibitors of the ETC?

Answer 33

Rotenone, Antimycin A, Cyanide azide