8.2 Cell Respiration

Question 1

Oxidation and Reduction

Answer 1

chemical processes that always occur together b/c they involve the transfer of electrons from one substance to another

Question 2

LEO GER

Answer 2

Loss Electrons Oxidation

Gain Electrons Reduction

Question 3

Electron Carriers

Answer 3

substances that can accept and give electrons as required

often link oxidations and reductions in cells

Question 4

Electron Carries in Cell Respiration

Answer 4

NAD - NADH

FADH - FADH2

Question 5

Phosphorylation

Answer 5

the addition of a phosphate molecule to an organic molecule

Question 6

Purpose of Phosphorylation

Answer 6

to make the molecule more unstable / more likely to react

“activates” the molecule

Question 7

Exergonic Reaction

Answer 7

releases energy

Question 8

Endergonic Reaction

Answer 8

absorbs energy

need to be coupled with exergonic reaction

Question 9

Coupled Endergonic and Exergonic Reaction Example:

Answer 9

Glucose (to) Glucose-6-phosphate (with hydrolysis of ATP)

Question 10

Glycolysis

Answer 10

1st step: Glucose to Glucose-6-phosphate (needs 1 ATP)
2nd step: Glucose-6-phosphate to Fructose-6-phosphate
3rd step: Fructose-6-phosphate to Fructose-1,6-bisphosphate (needs 1 ATP)
4th step: Fructose-1,6-bisphosphate to 2 Triose Phosphate
5th step: each Triose Phosphate to Glycerate-3-phosphate (yields ATP and NAD+ becomes NADH + H+)
Final Steps: G3P to Pyruvate
Net Yield: 2 ATP and 2 NADH and 2 Pyruvate

Question 11

The Link Reaction (mitochondrial matrix)

Answer 11

pyruvate is decarboxylated and oxidized to form acetyl coenzyme A (NAD+ to NADH)

Question 12

The Krebs Cycle (mitochondrial matrix)

Answer 12

2 decarboxylations and 4 oxidations

Products: 3 NADH, 1 FADH2, 1 ATP

Question 13

Oxidative Phosphorylation / Chemiosmosis (inner membrane and intermembrane space)

Answer 13

final stage of aerobic respiration
ADP phosphorylated to produce ATP using energy released by oxidation
electron transport chain: NADH and FADH2 donate electrons to electron carriers - electrons passed from carrier to carrier - energy utilized to transfer protons inner membrane from the matrix into the intermembrane space - protons flow down the concentration gradient through ATP synthase providing the energy needed to make ATP

Question 14

Role of Oxygen

Answer 14

final electron acceptor
accepts electrons and forms bonds with hydrogen
by using up hydrogen the proton gradient is maintained so that chemiosmosis can continue

Question 15

Adaptation

Answer 15

a change in structure so that something carries out its functions more efficiently

Question 16

Mitochondrion

Answer 16

semi-autonomous organelle: can grow and reproduce itself but depends on the rest of the cell for resources and is otherwise part of the cellular system
70S ribosomes and a naked loop of DNA are found in the matrix
site of aerobic respiration

Question 17

Outer Mitochondrial Membrane

Answer 17

separates the contents of the mitochondrion from the rest of the cell, creating a cellular compartment with ideal conditions for aerobic respiration

Question 18

Intermembrane Space

Answer 18

proteins are pumped into this space by the electron transport chain, the space is small so concentration builds up quickly

Question 19

Inner Mitochondrial Membrane

Answer 19

contains electron transport chains and ATP synthase

Question 20

Matrix

Answer 20

contains enzymes for the Krebs cycle and the link reaction

Question 21

Ribosome DNA

Answer 21

for expression of mitochondrial genes

Question 22

Cristae

Answer 22

projections of the inner membrane which increase the surface area available for oxidative phosphorylation