١�٣�/٠٨/١٧

١

Anabolism and catabolism

Metabolism

Forms of metabolic pathways

Linear Cyclic

١�٣�/٠٨/١٧

٢

• Single-step vs multi-step pathways

• A multistep enzyme pathway releases energy in smaller amounts that can be used by the cell

Feedback inhibition

• Product of a pathway controls the rate of its own synthesis by inhibiting an early step (usually the first “committed” step (unique to the pathway)

١�٣�/٠٨/١٧

٣

Feed-forward activation

• Metabolite early in the pathway activates an enzyme further down the pathway

Catabolism produces compounds for energy utilization

(1) Nucleoside triphosphates (e.g. ATP)

(2) Reduced coenzymes (NADH, FADH2,)

١�٣�/٠٨/١٧

�

١�٣�/٠٨/١٧

�

١�٣�/٠٨/١٧

7

١�٣�/٠٨/١٧

٧

Thioesters Have High Free Energies of Hydrolysis

• Thioesters are energy-rich compounds (10.22)

• Acetyl CoA has a ∆Go’ = -31 kJ mol-1 (10.23)

١�٣�/٠٨/١٧

٨

The pathway for catabolism of

glucose

١�٣�/٠٨/١٧

٩

Glycolysis

١�٣�/٠٨/١٧

١٠

Glycolysis summary

١�٣�/٠٨/١٧

١١

١�٣�/٠٨/١٧

١٢

١�٣�/٠٨/١٧

١٣

١�٣�/٠٨/١٧

١�

١�٣�/٠٨/١٧

١�

Glycolysis in summary

How many ATP and how many e-carriers are produced?

١�٣�/٠٨/١٧

١7

١�٣�/٠٨/١٧

١٧

١�٣�/٠٨/١٧

١٨