This week…

Please put your test corrections in the appropriate file on the table by the door.

(Please staple your corrections to your test

packet.)Also, please get your lab

notebook.

This week…

• MON: Finish Ch. 9

• TUE: Case Study (Day One) & Lab Intro

• WED: Lab

• THU: Case Study (Day Two) & Lab Wrap-Up

• *Your Osmosis Lab & Enzyme Lab are graded and in PowerSchool. *I’ll be working on grading your FRQs this week.

1. Why is respiration important?- Consumption of food & oxygen to produce CO2, water & energy

- C6H12O6 + 6O2 6CO2 + 6H2O + energy (ATP + heat)

Chapter 9: Cellular Respiration: Harvesting Chemical Energy

Light energy

ECOSYSTEM

CO2 + H2O

Photosynthesisin chloroplasts

Cellular respiration

in mitochondria

Organicmolecules

+ O2

ATP

powers most cellular work

Heatenergy

1. Why is respiration important?- Consumption of food & oxygen to produce CO2, water & energy


- Exergonic (releases lots of energy… -686 kcal/mol)

- All foods can be metabolized as fuel (carbs, proteins, fats)


1. Why is respiration important?

2. What are redox rxns?- Reduction & oxidation

- LEO says GER

- Loss of Electrons – Oxidation : Gain of Electrons – Reduction

- Hint: electrons move with H atoms…H = e- + H+

- ┌----oxidation-----┐


- └----reduction----┘

- ENERGY COUPLING!!!

- (Oxidation is exergonic…reduction is endergonic)



2. What are redox rxns?

3. What are the 3 main steps of respiration?- Glycolysis

- Citric Acid Cycle (Krebs Cycle)

- Oxidative Phosphorylation - Electron Transport Chain (ETC)- Chemiosmosis



Electronscarried

via NADH

Glycolysis

Glucose Pyruvate

ATP

Substrate-levelphosphorylation

Electrons carried via NADH and

FADH2

Citric acid cycle

Oxidativephosphorylation:electron transport

andchemiosmosis

ATPATP

Substrate-levelphosphorylation

Oxidativephosphorylation

Mitochondrion



3. What are the 3 main steps of respiration?

4. What happens during glycolysis?- Glucose (6-C) is split in the cytosol into two 3-C pyruvate molecules- 10 steps- NO oxygen needed



Glycolysis Citricacidcycle


ATP ATP ATP

2 ATP

4 ATP

used

formed

Glucose

2 ADP + 2 P

4 ADP + 4 P

2 NAD+ + 4 e- + 4 H + 2 NADH + 2 H+

2 Pyruvate + 2 H2O

Energy investment phase

Energy payoff phase

Glucose 2 Pyruvate + 2 H2O

4 ATP formed – 2 ATP used 2 ATP

2 NAD+ + 4 e– + 4 H + 2 NADH + 2 H+




4. What happens during glycolysis?

5. How is the ATP made in glycolysis?- Substrate-level phosphorylation – ATP produced from the transfer of a

phosphate group from a substrate to ADP- ATP made one at a time


Enzyme Enzyme

ATP

ADP

Product

SubstrateP

+





5. How is the ATP made?

6. How do electrons get from glucose to O2?- NAD+ - nicotinamide adenine dinucleotide- Coenzyme (form of niacin…a vitamin!)- Accepts 2 e- and a H+

- NADH and H+ will be very important later in the respiration reaction, as they participate in more ATP formation!


NAD+

H

O

O

O O–

O

O O–

O

O

O

P

P

CH2

CH2

HO OHH

HHO OH

HO

H

H

N+

C NH2

HN

H

NH2

N

N

Nicotinamide(oxidized form)

NH2+ 2[H]

(from food)

Dehydrogenase

Reduction of NAD+

Oxidation of NADH

2 e– + 2 H+

2 e– + H+

NADH

OH H

N

C +

Nicotinamide(reduced form)

N

H+

H+







6. How do electrons get from glucose to O2?

7. How does pyruvate get into the mitochondria for the Krebs Cycle?

- Active transport across membrane- 3 step process


CYTOSOL MITOCHONDRION

NADH + H+NAD+

2

31

CO2 Coenzyme APyruvate

Acetyl CoA

S CoA

C

CH3

O

Transport protein

O–

O

O

C

C

CH3


1. Why is respiration important?2. What are redox rxns?3. What are the 3 main steps of respiration?4. What happens during glycolysis?5. How is the ATP made?6. How do electrons get from glucose to O2?7. How does pyruvate get into the mitochondria for the Krebs

Cycle?8. What happens during the Citric Acid Cycle?

- Mitochondrial matrix- 8 steps- “Spins" 2X per glucose (1X for each pyruvate)


NAD+

ATP

2 CO2

3 NAD+

3 NADH

+ 3 H+

ADP + P i

FAD

FADH2

Citricacidcycle

CoA

CoA Acetyl CoA

NADH

+ H+

CoA

CO2

Pyruvate(from glycolysis,2 molecules per glucose)

ATP ATP ATP

Glycolysis Citricacidcycle



1. Why is respiration important?2. What are redox rxns?3. What are the 3 main steps of respiration?4. What happens during glycolysis?5. How is the ATP made?6. How do electrons get from glucose to O2?7. How does pyruvate get into the mitochondria for the Krebs

Cycle?8. What happens during the Citric Acid Cycle?9. How many ATP so far?

- 4 total, 2 from glycolysis & 2 from Krebs Cycle- ALL from substrate-level phosphorylation









8. What happens during the Citric Acid Cycle?

9. How many ATP so far?

10. How many electron carriers so far?

- 10 NADH

- 2 FADH2


1. Why is respiration important?2. What are redox rxns?3. What are the 3 main steps of respiration?4. What happens during glycolysis?5. How is the ATP made?

6. How do electrons get from glucose to O2?7. How does pyruvate get into the mitochondria for the Krebs

Cycle?8. What happens during the Citric Acid Cycle?9. How many ATP so far?10. How many electron carriers so far?11. What happens during electron transport?

- rxns in inner mitochondrial membrane

- electrons flow from electron carriers to electronegative O2

- many SMALL steps instead of one BIG step

12. Why do electron carriers NEED to “break the fall?”


H2 + 1/2 O2 2 H 1/2 O2

(from food via NADH)

2 H+ + 2 e–

2 H+

2 e–

H2O

1/2 O2

Controlled release of energy for synthesis of

ATPATP

ATP

ATP

Electro

n tran

spo

rt chain

F

ree

ener

gy, G

(b) Cellular respiration(a) Uncontrolled reaction

Fre

e en

ergy

, G

H2O

Explosiverelease of

heat and lightenergy

+


Glycolysis Citircacidcycle


ATP ATP ATP

H2O

O2

NADH

FADH2

FMN

Fe•S Fe•S

Fe•S

O

FAD

Cyt b

Cyt c1Cyt c

Cyt aCyt a3

2 H + + 12

III

III

IV

Multiproteincomplexes

0

10

20

30

40

50F

ree

en

erg

y (G

) re

lativ

e t

o O

2 (k

cl/m

ol)

Figure 9.13 Free-energy change during electron transport











11. What happens during electron transport?

12. Why do electrons NEED to “break the fall?”

13. How is ATP made during chemiosmosis?


MITOCHONDRIAL MATRIX

INTERMEMBRANE SPACE

H+

H+

H+

H+

H+

H+ H+

H+

P i

+ADP

ATP

A rotor within the membrane spins clockwise whenH+ flows pastit down the H+

gradient.

A stator anchoredin the membraneholds the knobstationary.

A rod (or “stalk”)extending into the knob alsospins, activatingcatalytic sites inthe knob.

Three catalytic sites in the stationary knobjoin inorganic Phosphate to ADPto make ATP.

Figure 9.14 ATP synthase, a molecular mill


electron transportand chemiosmosis

Glycolysis

ATP ATP ATP

InnerMitochondrialmembrane

H+

H+H+

H+

H+

ATPP i

Protein complexof electron carners

Cyt c

I

II

III

IV

(Carrying electronsfrom food)

NADH

FADH2

NAD+

FAD+ 2 H+ + 1/2 O2

H2O

ADP +

Electron transport chainElectron transport and pumping of protons (H+),

which create an H+ gradient across the membrane

ChemiosmosisATP synthesis powered by the flowOf H+ back across the membrane

ATPsynthase

Q

Oxidative phosphorylation

Intermembranespace

Innermitochondrialmembrane

Mitochondrialmatrix

Citircacidcycle

Figure 9.15 Chemiosmosis couples the electron transport chain to ATP synthesis

Electron shuttlesspan membrane

CYTOSOL 2 NADH

2 FADH2

2 NADH 6 NADH 2 FADH22 NADH

Glycolysis

Glucose2

Pyruvate

2AcetylCoA

Citricacidcycle

Oxidativephosphorylation:electron transport

andchemiosmosis

MITOCHONDRION

by substrate-levelphosphorylation

by substrate-levelphosphorylation

by oxidative phosphorylation, dependingon which shuttle transports electronsfrom NADH in cytosol

Maximum per glucose:About

36 or 38 ATP

+ 2 ATP + 2 ATP + about 32 or 34 ATP

or

Figure 9.16 ATP yield per molecule of glucose at each stage of cellular respiration

Figure 9.16 ATP yield per molecule of glucose at each stage of cellular respiration (UPDATED)














14. What happens when there is no O2?

- anaerobic respiration (fermentation)


Glucose

CYTOSOL

Pyruvate

No O2 presentFermentation

O2 present Cellular respiration

Ethanolor

lactate

Acetyl CoA

MITOCHONDRION

Citricacidcycle

Figure 9.18 Pyruvate as a key juncture in catabolism

2 ADP + 2 P i 2 ATP

GlycolysisGlucose

2 NAD+ 2 NADH

2 Pyruvate

2 Acetaldehyde2 Ethanol

(a) Alcohol fermentation

2 ADP + 2 P i 2 ATP

GlycolysisGlucose

2 NAD+ 2 NADH

2 Lactate

(b) Lactic acid fermentation

H

H OH

CH3

C

O–

OC

C O

CH3

H

C O

CH3

O–

C O

C O

CH3O

C O

C OHH

CH3

CO22

2 Pyruvate

+2 H+

Figure 9.17 Fermentation














14. What happens when there is no O2?

15. How do the other foods we eat get catabolized?


Amino acids

Sugars Glycerol Fattyacids

Glycolysis

Glucose

Glyceraldehyde-3- P

Pyruvate

Acetyl CoA

NH3

Citricacidcycle


FatsProteins Carbohydrates

Figure 9.19 The catabolism of various molecules from food

1. Why is respiration important?2. What are redox rxns?3. What are the 3 main steps of respiration?4. What happens during glycolysis?5. How is the ATP made?

6. How do electrons get from glucose to O2?7. How does pyruvate get into the mitochondria for the Krebs Cycle?8. What happens during the Citric Acid Cycle?9. How many ATP so far?10. How many electron carriers so far?11. What happens during electron transport?12. Why do electrons NEED to “break the fall?”13. How is ATP made during chemiosmosis?

14. What happens when there is no O2?15. How do the other foods we eat get catabolized?16. How is cellular respiration controlled?


Glucose

Glycolysis

Fructose-6-phosphate

Phosphofructokinase

Fructose-1,6-bisphosphateInhibits Inhibits

Pyruvate

ATPAcetyl CoA

Citricacidcycle

Citrate


Stimulates

AMP

+

– –

Figure 9.20 The control of cellular respiration

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