Chapter 9- Lecture Outline

Question 1

Metabolism II

Answer 1

Flows into an ecosystem as sunlight and leaves as heat

Question 2

¥ Catabolic Pathways: (3 things)

Answer 2

¥ Yield energy by oxidizing organic fuels
¥ The breakdown of organic molecules is exergonic
¥ Results in the production of ATP

Question 3

¥ Two types of pathways:

Answer 3

Ð Fermentation

Ð Cellular respiration

Question 4

¥ Metabolism involves the transfer of electrons

Ð These are oxidation reduction reactions: ____________________

Answer 4

Redox reactions

Question 5

¥ Molecules can ___________ or ____________ electrons

Answer 5

accept or donate

Question 6

Ð _____________= accepted electrons

Ð ____________= donated electrons

Answer 6

Reduced

Oxidized

Question 7

__________________
Ð A molecule is reduced when it gains an electron
Ð A molecule is reduced when it gains a proton and an electron
¥ A hydrogen atom

Answer 7

¥ Reduction

Question 8

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Ð	Three ways to oxidize a molecule
¥	Losing a hydrogen atom
¥	 Losing an electron
¥	By gaining an oxygen atom

Answer 8

¥ Oxidation

Question 9

Ð Carrier Molecules

Answer 9

Ð Electrons are not bouncing around free in the cytoplasm

¥ Are transferred on carrier molecules

Question 10

Carrier molecules are usually Usually transferred in the form of a

Answer 10

Hydrogen Atom

Question 11

Ð Carrier molecules

Answer 11

¥ Nicotinamide adenine dinucleotid (NAD + )
¥ Nicotinamide adenine Dinucleotide phosphate (NADP+)
¥ Flavine adenine Dinucleotide (FAD)

Question 12

In a Redox reaction the carrier molecule is

Answer 12

NAD+

Question 13

¥ Respiration is a cumulative function of three metabolic stages

Answer 13

Ð Glycolysis
Ð The Citric Acid Cycle
Ð Electron Transport Chain

Question 14

The purpose of Cellular Respiration is to make

Answer 14

ATP

Question 15

=Overview of Cellular Respiration

Answer 15

(Glucose Catabolism)

Question 16

Glycolysis takes place is the

Answer 16

cytosol

Question 17

Ð Glycolysis is the first step

Answer 17

¥ This splits glucose into two pyruvate
¥ Produces a net of two ATP
¥ Produces a net of two NADH+ H+

Question 18

The pyruvate can go to fermentation to produce

Answer 18

acid or alcohol

Question 19

Ð The Pyruvate can go to the Kreb’s cycle in the ______________

Answer 19

mitochondria 
¥	This will produce
Ð	 CO2
Ð	NADH+ H+
Ð	FADH2

Question 20

¥ The carrier molecules send electrons to the

—

Answer 20

ETC

Question 21

Ð The ETC

Answer 21

¥ Takes the electrons
¥ Uses them to pump hydrogen ions across a membrane
¥ Uses this energy for producing ATP

Question 22

¥ Glycolysis

Answer 22

Ð Means “splitting of sugar”
Ð Breaks down glucose into pyruvate
Ð Occurs in the cytoplasm of the cell
Ð harvests energy by oxidizing glucose to pyruvate

Question 23

¥ Glycolysis consists of two

(4) major phases

Answer 23

Ð Energy investment phase
Ð Energy payoff phase
Ð Glycolysis energy investment phase
Ð Glucose

Question 24

¥	Receives a phosphate
¥	Changed to Fructose-6-phosphate 
¥	Receives another phosphate 
Ð	Now, Fructose 1,6-phosphate 
¥	It is now split
Ð	G-3-p
Ð	DHAP
Costs 2 ATP

Answer 24

Energy Investment Phase

Question 25

``` Each G-3-P gets an inorganic phosphate ¥ Makes 2 NADH in the process ¥ Becomes 1,3 bisphosphoglycerate Ð Phosphate is taken off the 1,3 bisphosphoglycerate ¥ Forms ATP (Two total) ¥ Forms 3-phosphoglycerate Ð 3-phosphoglycerate is changed to 2 phosphoglycerate Ð 2 phosphoglycerate ¥ Loses H2O and becomes phosphopheonolpyruvate Ð Phosphopheonolpyruvate ¥ Loses the Phosphate 2ATP ¥ Forms Pyruvate ```

Answer 25

¥ The Glycolysis Energy Payoff Phase (Conservation)

Question 26

¥ The Citric Acid Cycle

Answer 26

Ð Completes the energy-yielding oxidation of organic molecules Ð Takes place in the matrix of the mitochondrion ¥ Pyruvate is taken to the matrix ¥ Is converted to acetyl CoA Ð Forms another NADH Ð Loses a CO2 Ð Acetyl CoA enters the Citric Acid cycle

Question 27

¥ The Citric Acid Cycle | Ð Completes the energy-yielding oxidation of

Answer 27

organic molecules

Question 28

Ð Takes place in the matrix of the mitochondrion

Answer 28

¥ Pyruvate is taken to the matrix ¥ Is converted to acetyl CoA Ð Forms another NADH Ð Loses a CO2

Question 29

¥ The Citric Acid Cycle (Kreb‘s Cycle)

Answer 29

``` Ð Acetyl-CoA Enters the Cycle Ð Loses the CoA Ð The two carbons join the 4 of oxaloacetic acid ¥ This is now Citric Acid Ð This will oxidize the rest of the glucose ¥ Lose Hydrogen Atoms to three NAD+ ¥ Lose Hydrogen atoms to FAD ¥ Gives offs TwoCO2 Make an ATP ```

Question 30

¥ After the Citric Acid Cycle | Ð NADH+H+ and FADH2 go to the ETC

Answer 30

``` Oxidative Phosphorylation Ð During oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis Ð NADH and FADH2 ¥ Donate electrons to the electron transport chain ¥ powers ATP synthesis ¥ The Electron Transport Chain Ð A series of redox reactions Ð starts with NADH+ H+ or FADH2 Ð Electrons are passed to membrane bound Carrier molecules ¥ FMN ¥ Coq ¥ Cyt b ¥ Cyt c1 ¥ Cyt c ¥ Cyt a ¥ Cyt a3 ¥ Final electron acceptor is 02 Ð For aerobic Respiration Ð This pumps Hydrogen ions out of a prokaryote ```

Question 31

__________________ Ð The Energy-Coupling Mechanism Ð Uses energy in the form of a H+ gradient across a membrane to drive cellular work Ð The resulting H+ gradient ¥ Stores energy ¥ Drives chemiosmosis in ATP synthase ¥ Is referred to as a proton-motive force Ð ATP synthase ¥ H+ Go back to the matrix through ATP synthase ¥ Is the enzyme that actually makes ATP ¥ Net ATP Per Glucose Equals Approximately 36

Answer 31

Ð Chemiosmosis

Question 32

Ð Two net ATP from Glycolysis Ð Two ATP from the Citric Acid Cycle Ð Each NADH =3ATP

Answer 32

¥ Two NADH from Glycolysis ¥ Two NADH fro pyruvate to acetyl CoA ¥ 6 from the Citric Acid cycle ¥ (6+2+2)3=30 ATP

Question 33

Ð Minus two ATP due to the shuttle for pyruvate

Answer 33

¥ Fermentation

Question 34

Ð Each FADH2 =2 ATP

Answer 34

¥ Two FADH2 from the citric acid cycle | ¥ (2)2=4 ATP

Question 35

¥ About 40% of the energy

Answer 35

Ð Is transferred to ATP during cellular respiration, making approximately 38 ATP Ð Actually 36 to 32

Question 36

¥ Fermentation

Answer 36

Ð When there are no final electron acceptors

Question 37

¥ Pyruvate goes the other way

Answer 37

Ð The partial oxidation of sugar | Ð Uses an organic molecule to accept electrons

Question 38

¥ NADH is oxidized to NAD+ | Ð This is the main function of fermentation

Answer 38

¥ If a CO2 is lost from pyruvate ethanol is produced ¥ If pyruvate is reduced it becomes lactic acid Ð The Evolutionary Significance of Glycolysis

Question 39

__________________ Ð Occurs in nearly all organisms Ð Probably evolved in ancient prokaryotes before there was oxygen in the atmosphere

Answer 39

¥ Glycolysis