Metabolism

• Metabolism = all chemical reactions in the body – Catabolism = breaks down molecules

• Energy released exergonic• released energy can be used to make ATP

– Cellular Respiration

– Anabolism = adds molecules together/makes larger molecules

• Requires energy input • energy supplied by ATP• creates energy storage molecules and build new/needed molecules

5-3

Cellular Respiration

• The breakdown of nutrient molecules to make/generate ATP– Aerobic respiration: uses/requires O2– Anaerobic respiration: does not use O2

ATP-ADP Cycle

ATP

ADP

Phosphate

+

Energy from broken

covalent bond in nutrients

(e.g., carbs)

Phosphate

+

Usable energy for cell

Catabolic rxn ATP production

(i.e., phosphorylation of ADP)

“downhill rxns” “uphill rxns”

Coupled Reactions: Oxidation-Reduction• Oxidation=losing electrons • Reduction=gaining electron

• Reduction & oxidation are coupled reactions– As a e- is transferred one molecule is oxidized and the other reduced– NAD and FAD H carriers (& coenzymes)

• Derived from niacin and riboflavin (B vitamins)

4-29

O.I.L. R.I.G.

Cellular Respiration and nutrient sources

5-4

In later lecture

Aerobic Respiration (~26+ steps)

Review of Relevant Compartments

A. Plasma

B. Interstitial Fluid

C. Intracellular cytoplasm

D. Mitochodria

e. Mitochondrial matrix

f. Intermembrane space

A BC

E

F

D

SUPER SIMPLE, OVERALL REACTION: AEROBIC RESPIRATION

C6H12O6 + O2 + P + ADP ATP + H2O + CO2 + HEAT

substrates

Aerobic Respiration:• Breakdown of nutrients to produce ATP with the use of O2

• A complex biochemical pathway that has several major steps– Glyocolysis: breakdown of glucose into pyruvate

WHEN SUFFICIENT O2 IS PRESENT WILL PROCEED TO:– Conversion of pyruvate into acetylCoA– Krebs Cycle: processing of Acetyl CoA to release H’s (p+ & e-) for the ETC– Electron Transport Chain: the use of e- and H+ to create ATP through oxidative

phophorylation, uses O2 and produces H2O

• SUPER SIMPLE, OVERALL REACTION:

• C6H12O6 + O2 + P + ADP ATP + H2O + CO2 + HEAT

NAD & FAD can be though of as electron (e-) carriers. They carry e- to the ETC

Krebs Cycle

5-18

• NADH • FADH2• ATP

Function of Oxygen

• Electrons added to beginning of ETC are passed along until reach end– Have to be given

away or would stop ETC

– O2 accepts these electrons and combines with 4H+s

• O2 + 4 e- + 4 H+ 2 H20 5-25

ATP Synthase animations

• http://www.youtube.com/watch?v=H7P4xOUPYVw• w/ fluorescent actin and reversible rxn (skip)

• http://www.youtube.com/watch?v=3y1dO4nNaKY (good tutorial on gradients and chemiosmosis)

• http://www.youtube.com/watch?v=xbJ0nbzt5Kw&feature=relmfu (tutorial of etc, more detail then needed, but nice animation)

Uses of Different Energy Sources

5-48

deamination

Beta oxidation

Acetyl CoA• Is a common substrate for energy and synthetic

pathways

5-34

5-30