Energy Production And Regulation

Question 1

Metabolism definition

Answer 1

The interconversion of biological molecules in small chemical steps

Question 2

Compare catabolic pathways to anabolic pathways

Answer 2

Catabolic:

• break down larger molecules into smaller ones (intermediary metabolites)
• release large amounts of free energy (energy that is available for work)
• oxidative; releases H atoms, so acts as a reducing power (NADH eg)

Anabolic:

• synthesise larger components from intermediary metabolites
• use energy from catabolism (ATP)
• reductive (RIG - gain ie uses H released in catabolism)

Question 3

Whats the catabolic metabolism pathway for

• amino acids?
• glucose?
• fatty acids?
• alcohol?

Answer 3

Amino acids; form NH3 which forms urea, or keto-acids which forms acetyl coA and then CO2

Glucose; forms pyruvate and then acetyl coA and then CO2

Fatty acids; form acetyl co A and then CO2

Alcohol; forms AcetylcoA and then CO2

Question 4

4 stages in catabolism (breakdown of large compounds from our diets) and where each occurs

Answer 4

Stage 1: extracellular, GI tract. Breakdown of large, fuel molecules to building block for absorption

Stage 2: cytosolic and mitochondrial, breakdown to metabolic intermediates (OXIDATIVE - release of reducing power eg NADH)

Stage 3: mitochondrial; TCA cycle/ krebs. Oxidative and acetyl coA oxidised to CO2

Stage 4: mitochondrial: oxidative phosphorylation. Conversion of reducing power (eg NADH) into ATP