14 - Metabolism – general characteristics of anabolic and catabolic processes. Key metabolites (role of pyruvate and acetyl-CoA). Phases of the aerobic metabolism.

sections

• metabolism

• anabolism

• catabolism

• function of pyruvic acid

• pyruvate

• acetyl-CoA

• aerobic metabolism 3 steps

• metabolism

• breakdown and transformation of food into energy

anabolism

build up of substances

catabolism

breakdown of substances

• function of pyruvic acid

• supplies energy to living cells through citric acid cycle (krebs cycle)

• when oxygen lacking, it ferments to produce lactic acid

pyruvate

• output glycolysis = 1 glucose broken down to 2 pyruvate

• Pyruvate then transported to mitochondria for citric cycle

• In absence of O2, pyruvate ferments and becomes lactate (which can regenerate glucose)

• Can also be used for anabolic synthesis of AA or FA

acetyl CoA

• participates in protein, carbohydrate + lipid metabolism

• role: transfer acetyl group to citric cycle to be oxidised for energy

• Acetyl-CoA, NADH+ATP allosterically inhibit pyruvate dehydrogenase complex and activate pyruvate dehydrogenase kinase

• aerobic metabolism 3 steps

• degrading biopolymers →monomers

• Monomers converted to acety- CoA

• Degrading acetyl-CoA → Co2 + H+