Three Metabolic Pathways

Pathways of Cell Respiration

2 2 34

2 ATP

Glycolysis Summary

GLUCOSE

PYRUVATE

PYRUVATE

NADHH+

NADHH+

To ETC

Ready to use

2 NAD+2 NADH

Fermentation Some orgs lack the O2 or tools

necessary for KC or ETC Leads to buildup of useless pyruvate

and NADH Fermentation

Elimination of pyruvate Recycling of NAD+

PYR

PYRGlucoseGlucose

2 ATP

Ferm

enta

tion

Aerobic Cell Resp

Alcohol Fermentation

Diffusesout of cell

Diffusesout of cell

Available for glycolysis

Alcohol Fermentation Uses

Lactic Acid Fermentation

Diffusesout of cell

Available for glycolysis

PYRUVATE

Pyruvate Oxidation(for each of 2 pyruvates)

CO2

NADH

ACETYL CoA

CoA

To Cycle

Diffuses Away (Waste)

To ETC

Citric Acid Cycle

Subsequent rxns break down the citrate into another oxaloacetate.

Acetyl CoA (2C)

Oxaloacetate (4C)

Citrate (6C)

NADHFADH2

NADH

Citric Acid Cycle

4COXALOACETATE

2C

ACETYL CoA

6CCITRATE

5C

NADH4C

ATP

GlycolysisBefore

Glucose2 NAD2 ADP + P

After2 Pyruvate2 NADH2 ATP

Matrix (Krebs)

Matrix (ETC)

Where needed

Krebs Cycle (including lead-up steps)Before

2 Pyruvate8 NAD2 FAD2 ADP + P

After6 CO2

8 NADH2 FADH2

2 ATP

Diffuse away

IMM (ETC)

IMM (ETC)

Where needed

ETC Chemiosmosis

AlternateCatabolism

Deamination

Regulation Phosphofructokinase

Catalyzes one step of glycolysis

Inhibited by ATP and Citrate

Stimulated by ADP and AMP

AA production Inhibited by large

amounts of AA’s

Cell Respiration Review

Which part of CR?1. CO2 is given off

2. Most water is formed3. Oxaloacetate4. Pyruvate production5. ATP Production

Cell Respiration ReviewPut the following molecules in order

of increasing electronegativity:GlucoseFADH2

O2

NADH

GlucoseNADHFADH2

O2

Cell Respiration Review1. What is the primary product of cellular

respiration?

2. Why would an organism carry out fermentation when aerobic cellular respiration is so much more profitable?

3. What is the energy source for the ETC?

4. What’s the immediate result of an ETC?

5. What can a cell do with that?