Cell processes

Question 1

What is glycolysis?
Products?

Answer 1

Glucose to pyruvate

Generated 2 ATP for each glucose and NADH

Question 2

What happens in aerobic respiration?

Answer 2

Pyruvate to acetyl-CoA and CO2
34 ATP produced

Acetyle CoA - produces much NADH in citric acid cycle

Electron transport chain driven by H ion gradient across inner mitochondrail membrane produces 34 ATP

Question 3

What happens in anaerobic respiration

Answer 3

Pyruvate converted to lactate

Question 4

What does the Krebs citric acid cycle prodcue

Answer 4

2 ATP, 6 NADH, 4 CO2 for each glucose in the first turn or cycle

Net result in 30 ATP molecules per glucose

Question 5

What is oxidative phosphorylation -

Answer 5

NADH oxideized to NAD+, extracting energy and allowing citric acid cycle to continue

Electron transfer from donors to acceptros in redox reactions - releases energy which is used to form ATP

Energy release is harnessed to transport froteins across inner mitochondrial membrane

pH gradient and electrical potential across membrane

ATP synthase generates ATP from ADP

PRoduces reactive oxygen speies such as superoxide and hydrogen peroxide which leads to propagation of free radicals

Question 6

What are ROS?

Answer 6

Highly reactive ions that possess unpaired electrons

Byproduct of normal oxygen metabolism from mitochondria

Some oxygen is prematurely and incompletely reduced to form superoxide O2- radical

Can inactivate specific enzymes, initiate lipid peroxidation in H2O2 form

Question 7

What enzymes reduce the effects of radical oxygen species?

Answer 7

Catalase
Superoxide dismutase

Question 8

What are harmful effects of ROS?

Answer 8

Damage to DNA
Oxidation of polydesaturated fatty acids in lipids (lipid peroxidation)
Oxidation of amino acids in proteins
Inactivation of specific enzymes by oxidation and co-factors

Cell damage triggers apoptosis

Question 9

What is gluconeogenesis

Answer 9

Anabolic pathway that generates glucose from non-carbohydrate substrates - lactate, glycerol, amino acids

Question 10

What is the pentose phosphate pathway?

Answer 10

Alternative to glycolysis
Oxidation of glucose

Anabolic process that generates NADPH and pentose sugars

Oxxurs in cyroplasm

NAPDH used to prevent oxidative stress by reducing glutathione via glutathione reductase which converts H2O2 to H2O