chapter 7 metabolism: transformations and interactions

Chapter 7Chapter 7Metabolism: Transformations and Metabolism: Transformations and

InteractionsInteractions

ENERGY

ENERGY

ENERGY

ENERGY

Anabolic Processes (build up)

Examples:

glucose + glucose +...... glycogen

amino acid + amino acid +...... protein

Catabolic Processes (break down)

Examples:

glycogen glucose + glucose +......

protein amino acid + amino acid +......

ATP (Adenosine Triphosphate)

O

N

N

N

N O P O P O P

O

O

O

O

O

O

O

OH OH

NH2

Adenosine

3 Phosphates

Transfer of Energy Utilizing ATP

How Efficient is this Process?

From the food we ingest, we only capture about 50% of the energy in the bonds in the form of ATP.

When we utilize the ATP to “fuel” other anabolic processes, we only utilize about 50% of the ATP’s energy.

Where does the “LOST ENERGY” go?

Overview of energy

metabolism.

TCACycle

Protein(amino acids)

Lipids

Carbs

Energy Production

Lets Start with Carbs: Glycolysis (anaerobic)

Release of Small Amount

of Energy

A Simplified Eukaryote Cell

CytoplasmCell Membrane

Nuclear Membrane

Chromosomes

Mitochondria

Endoplasmic Reticulum(ribosomes)

Pyruvate-to-Acetyl CoA (aerobic)

Irreversible Step

Cofactor

The Breakdown of Acetyl CoA

ToEnergy

(aerobic)

TCACycle

Electron Transport Chain

SUMMARY:

Glucose-to-energy pathway

Fatty Acid Oxidation

Fats-to-energy

pathway

Transamination:

Making Nonessential Amino Acid

Deamination to give Keto Acids

Amino Acids-to-energy pathway

Urea synthesis

What happens to the NH3?

Urea excretion Amino Acids

bloodstream

Liver

Kidney

bloodstream

Electron Transport Chain

Why does Fat Produce more Energy than Glucose?

Mol. Weight = 256.42Acetyl CoA produced = 8

ATP’s produced = 129ATP’s per gram = 0.50

Mol. Weight = 180.16Acetyl CoA produced = 2

ATP’s produced = 38ATP’s per gram = 0.21

During Feasting - High Dietary Intake

During Fasting - Low Dietary Intact

If Fasting Continues - Still Low Dietary Intact

Ketosis: Ketone Body formation

Alcohol metabolism

Alternate routefor Acetyl CoA

FatNADH

blocks entry