Dr. Wipa Suginta School of Biochemistry Institute of Science SUT BIOENERGETICS Dr. Wipa Suginta School of Biochemistry Institute of Science SUT

Catabolism vs. Anabolism METABOLISM Catabolism vs. Anabolism

RELATIONSHIP OF NUTRIENTS, BIOSYNTHESIS, AND GROWTH

METABOLIC PATHWAY IS A MULTI-STEP PROCESS The glycolytic pathway involves 10 reactions.

THE DIRECTION OF THE METABOLIC PATHWAY IS DETERMINED BY THE NET FREE ENGERGY (∆G)

METABOLIC CONTROL Control at enzyme activity level

2. Control by energy status (energy charge ratio) Anabolism Catabolism

3. Feedback/feedforward mechanism

4. Control by hormone Glucocorticoids, growth hormone, thyroid hormone (+) glucagon (+) Norepinephrin (+) Insulin (-) In adipose cells, epi-/norepinephrine/glucagon/adrenocorticotropic hormones trigger 7TM receptors that activate adenylate cyclase. The increased level of cAMP stimulates protein kinase A, which activates the lipases by phosphorylating them. In contrast, insulin inhibits lipolysis. The released fatty acids are not soluble in blood plasma, and so, on release, serum albumin binds the fatty acids and serves as a carrier. By these means, free fatty acids are made accessible as a fuel in other tissues.

ATP CYCLE ATP is a cellular currency ATP has three phosphoyl groups. Breaking the bond linked between the phosphoryl groups generates substantial amount of energy.

The use of ATP 1. Muscle movement

2. Active transport

3. Cellular growth and human development

Other high energy compounds are also energy suppliers for cells

High energy compounds transfer phosphoryl group to ATP

In our cells, ATP is directly generated by high energy compounds through ‘substrate level phosphorylation’

Energy production from oxidation of nutrition