When glucose entersa cell, a phosphate group(from ATP) gets attachedto C #6.

Phosphorylation

C6H12O6 + PO4 glucose-6-phosphate

All glucose inside a cellmust be in the form ofgluc-6-phos in order tobe used.

Non-reversible processin all except LIVER CELLS.

Glycogenesis

Glucose is stored asGLYCOGEN (long chains of gluc-6-phosmolecules)

“genesis” = formation

Glycolysis

Gluc-6-phos + 2ATP Pyruvate + 4ATP

Anaerobic processhttp://www.science.smith.edu/departments/Biology/Bio231/glycolysis.html

“lysis” = breaking apart

Glucose H- C = O | H - C - OH |HO- C - H | H - C - OH | H - C - OH | H - C - OH H

Pyruvate (Pyruvic acid)

CH3 - C – COOH || O

Kreb’s Cycle

• Pyruvic acid (from glycolysis) goes into the mitochondria

• CO2 + H+ are split off and

leaves a 2 carbon (acetyl)Group http://www.science.smith.edu/departments/Biology/Bio231/krebs.html (step 1)

• Acetyl group combines w/ CoA acetyl CoA

Coenzyme

Organic compound made by cells that must combine with an enzyme in order to work.

Coenzyme may be a hydrogen “carrier”

Hydrogen carriers

NAD – nicotinamide

adenine

dinucleotide

FAD – flavin adenine dinucleotide

NAD + H+ NADH+

FAD + H+ FADH+

Coenzyme A

Coenzyme that is NOT a hydrogen carrier.

Coenzyme A carries a 2-carbon (acetyl) group

ADP

Is also a coenzyme – carries phosphate groups

First part of Kreb’s cycle

CoA carries acetyl groupsinto the Kreb’s cycleto transfer them to oxaloacetic acid toform CITRIC ACID (nameof cycle) http://www.science.smith.edu/departments/Biology/Bio231/krebs.html (step 2)

Kreb’s cycleis important inthe metabolism of:

• Carbohydrates• Proteins• Lipids

In one “turn” of the Kreb’s cycle…..

• 2 molecules CO2

• 4 molecules H2 (3 NADH + 1FADH)

1 molecule acetyl CoA

•1 molecule ATP

And, now for the Kreb’sCycle itself………

From glycolysis

CH3 – C – COOH || O

+ CoA

CH3 – C – CoA || OAcetyl CoA

Pyruvic acid

Step #1CH3 – C – CoA || O acetyl CoA

COOH |C = O |CH2

|COOHoxaloacetic acid

COOH | CH2

|HO – C – COOH | CH2

| COOH citric acid

NADNADH+

Animationhttp://www.science.smith.edu/departments/Biology/Bio231/krebs.html

(step 2)

Step #2 COOH | CH2

|HO – C – COOH | CH2

| COOH citric acid

COOH | CH2

| C – COOH || CH | COOH cis-aconitic acid(unstable intermediate)

COOH | CH2

| C – COOH || CH | COOH cis-aconitic acid(unstable intermediate)

Step #3

COOH | CH2

| H - C – COOH | HO - CH | COOH isocitric acid

Step #4 COOH | CH2

| H - C – COOH | HO - CH | COOH isocitric acid

COOH | CH2

| H - C – COOH | C = O | COOH oxalosuccinic acid

-2H

Step #5 COOH | CH2

| H - C – COOH | C = O | COOH oxalosuccinic acid

COOH | CH2

| CH2 | C = O | COOH -ketoglutaric acid

-CO2

Step #6 COOH | CH2

| CH2 | C = O | COOH -ketoglutaric acid

COOH | CH2

| CH2 | C = O | CoA succinyl CoA

-CO2

-2H

NADH+NAD

Step #7 COOH | CH2

| CH2 | C = O | CoA succinyl CoA

COOH | CH2

| CH2 | COOHsuccinic acid

+H2O

NADNADH+

Step #8 COOH | CH2

| CH2 | COOHsuccinic acid

COOH | CH || CH | COOH fumaric acid

-2H

Step #9 COOH | CH || CH | COOH fumaric acid

COOH | HO - CH | CH2 | COOH malic acid

+H2O

Step #10 COOH | HO - CH | CH2 | COOH malic acid

COOH | C=O | CH2 | COOH oxaloacetic acid(back to where we started!)

-2H

Animation Summaryhttp://www.science.smith.edu/departments/Biology/Bio231/krebs.html

(step 3)

Summary to end of Kreb’s Cycle

In Out

1 pyruvic acid 1 CO2 (as waste)

1 NAD 1 NADH

CoA Acetyl CoA

1 acetyl CoA 2 CO2 (as waste)

3 NAD 3 NADH

1 FAD 1 FADH2

1 ADP 1 ATP

What happens to the CO2 produced in the Kreb’s Cycle?

Diffuses from mitochondria cytoplasm (cytosol) bloodstream exhaled (whew!)

Electron Transport ChainThe pairs of hydrogen ions (-2H) fromthe Kreb’s Cycle enter the electrontransport chain.

There are a series of HYDROGENACCEPTORS (NAD, FAD & cytochromes)that, as they pass the hydrogen ions along, ATP is being produced.

What ultimately happens to pairs of H?

Oxygen is final acceptor of H produces H2O!

From 4 pairs of H 36-38 ATPs produced inthe electron transport chain!

Glucose ATP count?

Phosphorylation & glycolysis: 8 ATP

Kreb’s cycle & electron transport: 30 ATP

Total = 38 ATPs

Electron Transport Chain(Animation)

http://www.science.smith.edu/departments/Biology/Bio231/etc.html

Fat metabolism1 unit of FAT

3 fatty acids 1 glycerol

18 C each chain glycolysis

Kreb’s cycle & electron transport

38 ATP

Each 18 C 6 pyruvic acidSo total of 18 pyruvic acids

18 pyruvic acids 684 ATP

So, 684 + 38 = 722 ATPs!

What about protein?

Single amino acids are used to buildmuscle, bones, connective tissue, and cytoplasm and cell membraneof cells.

Not typically catabolized (broken down)for energy – only during starvation.

22 amino acids – 8 are “essential”

Chemistry of Digestion writing prompt:

The carbohydrates, proteins and lipids have now been broken down into

single sugars, amino acids or fatty acids and glycerol.  They are now in the liver. 

Describe, in detail, the process by which glucose creates ATP and then how the other substances

become ATP as well.  Be sure to include structures to

help your explanation.