California Science Standards #1f, 1g, 1i, 6d, 9a

1

Cellular RespirationCellular Respiration

Glycolysis, Fermentation, Krebs Cycle, Electron Transport Chain

2

ReviewReview

CO2 + H2O C6H12O6 + O2

Photosynthesis– Store Energy

C6H12O6 + O2 CO2 + H2O

Cellular respiration– Just the of photosynthesis– Release energy

reverse

3

Cellular RespirationCellular RespirationAn Overview (“Map”)

ATP

ATP

4

GlycolysisGlycolysis Breaks down glucose into pyruvic acid

– STEP 1: Two P’s (from two ATPs) attach to glucose, making a new 6-C compound

– STEP 2: The new 6-C compound is split into two 3-C molecules of PGAL (just like Calvin)

– STEP 3: The two PGALs each receive another Phosphate group; 2 NADHs formed

– STEP 4: All P’s are stripped off (eeek!), revealing 2 molecules of pyruvic acid

4 new ATPs are made when 4 ADPs receive the P’s

Glycolysis has a net yield of 2 ATPs. How?

5

Glucose

6-carbon compound

2 moleculesof PGAL

2 molecules of 3-C compound

2 moleculesof pyruvic acid

STEP 1

STEP 2

STEP 3

STEP 4

C C C C C C

C C C C C C PP

C C CP C C C P

C C CP P C C CP P

C C C C C C

-2 ATP

2 NAD+

4 ATP

6

Glycolysis, ContinuedGlycolysis, Continued

Watch

7

Cellular RespirationCellular RespirationCheck the Map…

ATP

ATP

8

FermentationFermentation

No oxygen? No problem…2 types: lactic acid fermentation,

alcoholic fermentationPros: can regenerate NAD+ when short on O2

– Keeps glycolysis going

Cons: Cannot produce ATP

9

Lactic Acid FermentationLactic Acid Fermentation Manufacture of yogurt, cheese Muscle cells

– “Anaerobic exercise” (sprints)– Lactic acid build-up (muscle burn, fatigue, cramps)

Pyruvic acid

Lactic acid

Glucose

C C C C C C C C C

C C C

NAD+ NADH + H+

10

Alcoholic FermentationAlcoholic FermentationBasis of wine and beer industries

– Yeast + fruit juice = alcohol

Takes place when making bread– CO2 makes bread rise; alcohol evaporates

Pyruvic acid

Ethyl alcohol

Glucose

C C C C C C C C C

C C

NAD+ NADH + H+

2-C compound

C C

CCO2

11

Section 7-1 ReviewSection 7-1 Review

Do page 131, #1-6

12

Cellular RespirationCellular RespirationCheck the Map…

ATP

ATP

13

Aerobic RespirationAerobic Respiration

Requires oxygenProduces nearly 20x as much ATP as is

produced by glycolysis alone2 major stages:

– Krebs cycle– Electron transport chain

14

Krebs CycleKrebs Cycle 1st stage of aerobic respiration Breaks down acetyl CoA, producing CO2,

hydrogen atoms, and ATP– STEP 1: Acetyl CoA combines with oxaloacetic acid to

produce citric acid– STEP 2: Citric acid releases a CO2 molecule to form a

5-C compound– STEP 3: The 5-C compound releases a CO2 molecule to

form a 4-C compound– STEP 4: The 4-C compound is converted into a new 4-

C compound– STEP 5: The new 4-C compound is converted back into

oxaloacetic acid

15

Citric acid

C C C C C C

Oxaloaceticacid

C C C C

C C

4-C compound

C C C C

C

ATP

NADH

5-C compound

C C C C C

C

NADH

NADH

4-C compound

C C C CFADH2

Krebs Krebs CycleCycle

16

Electron Transport ChainElectron Transport Chain

2nd stage of aerobic respirationLocated on inner membrane folds (cristae)

of mitochondrioncristae

17

Electron transport chain is here

18

19

Electron Transport, continuedElectron Transport, continued

Electron transport is the “clean-up batter”– “Bats” in NADH’s and FADH2’s (“base runners”) to

make mucho ATP (“runs” or RBI’s). How?

1. Electrons in NADH and FADH2 are “hot potatoes”

2. They get passed down the chain, and their “heat” helps pump protons from the matrix (inner compartment) to the outer compartment

3. The concentration gradient of protons drives the synthesis of ATP by chemiosmosis

20

21

22

Total ATP From Cellular Total ATP From Cellular RespirationRespiration