ch 18 - respiration

Question 1

what is glycolysis? where does it take place? aerobic or anaerobic process?

Answer 1

breakdown of glucose to 2 pyruvates
cytoplasm
anaerobic process

Question 2

describe all the steps of glycolysis

Answer 2

1) phosphoroylation - 2 phosphates (from 2 ATP) attach to glucose -> fructose biophosphate

2) lysis: hexose biphosphate -> 2 triose phosphate molecules

3) oxidation: H removed from each triose P -> coenzyme NAD -> 2 reduced NAD (NADH+)

4) dephosphorylation: P from each triose P transferred to 2ADP -> 2ATP | in total 4 ATP (substrate linked phosphorylation)

5) pyruvate produced

Question 3

what are the overall products from glycolysis

Answer 3

2 ATP
2 NADH+
2 pyruvate

Question 4

what are the 5 features of mitochondria

what do they do

Answer 4

matrix = enzymes for Kreb + link, has mDNA

cristae - increase SA for oxidative phosphorus

inner mitochondrial membrane - e- transport chain + ATP synthase

intermembrane space - small so conc. builds up quick

outer mitochondrial membrane - separates mitochondria from cell ensure aerobic conditions

Question 5

describe the link reaction for one pyruvate molecule

Answer 5

pyruvate -> CO2 released & NADH+ formed from H released -> acetyl group + coA -> acetylCoA

Question 6

where does the link reaction take place, what is another name for the reaction

Answer 6

mitochondrial matrix

oxidative decarboxylation

Question 7

what is the first step of the krebs cycle

Answer 7

oxaloacetate (4C) accepts acetylCoA (2C) -> citrate (6C)

CoA released here

Question 8

what is the second step of the krebs cycle (after citrate formed)

Answer 8

citrate
decarboxylation: 2CO2 released
oxidation: releases H atoms -> 3NADH+ & 1 FADH2 formed
substrate-linked phosphorylation: ADP + Pi -> ATP

back to oxaloactetate (4C)

Question 9

what are the final products of krebs cycle

Answer 9

2 CO2
3 NADH
1 FADH2
1 ATP

Question 10

what is another name for oxidative phosphorylation

Answer 10

chemiosmosis

Question 11

describe the process of oxidative phosphorylation

Answer 11

H given by NADH & FADH2 (krebs)

H -> H+ + e-

e- -> e- transport chain -> release e- as they more to each protein complex

E used to transport protons from matrix -> intermembrane space

proton conc. grad.

protons come back through facilitated diffused through ATP synthase (channel protein)

proton movement gives energy for ATP synthesis

O2 (final e- acceptor) + H+ + e- -> H2O