D3H1 Metabolism Integration

Question 1

anabolic/catabolic control

Answer 1

• thermodynamic asymmetry
• compartmentation
• hormonal control

Question 2

ATP and NADH usage: glycolysis vs gluconeogenesis

Answer 2

2 ATP/NADH (glycolysis) vs 6 ATP/2NADH used (gluconeogenesis)

Question 3

What anabolic/catabolic processes happen in mitochondrial matrix?

Answer 3

citric acid cycle

oxidative phosphorylation

beta oxidation

ketogenesis

amino acid synthesis and degradation

urea cycle

Question 4

What anabolic/catabolic processes happen in the cytosol?

Answer 4

glycolysis

gluconeogenesis

pentose phosphate pathway

fatty acid synthesis

nucleotide synthesis

amino acid synthesis and degradation

urea cycle

Question 5

What happens in organs during fed state?

Answer 5

-blood nutrient levels are generally high, favor energy use and storage

Question 6

What happens in organs during fasting state?

Answer 6

• protein synthesis downregulated

- energy production or energy release from stores (mobilization) favored

Question 7

postprandial state

Answer 7

• directly follows a meal
• elevated blood nutrient levels
• insulin release

Question 8

postabsorptive state

Answer 8

• fasting
• low blood nutrient levels
• glucagon release

Question 9

What’s released/absorbed after ingestion of food?

Answer 9

• hormones released: gastrin, secretin, cholecystokinin
• digestive enzymes secreted
• enterocyte absorption of nutrients

Question 10

effects of insulin

Answer 10

• glucose uptake by muscle and adipose (increased activity of GLUT4 transporter)
• liver glycogen synthesis, glycolysis
• fat synthesis in liver and adipocytes, inhibition of lipolysis
• amino acid transport (liver & muscle)
• protein synthesis

Question 11

What happens during fasting phase?

Answer 11

• begins w/ diminished nutrient flow, pancreatic alpha-cells release glucagon
• fatty acid mobilization for muscle
• glucose saved for brain
• lipolysis in adipocytes

Question 12

possible fates of glucose-6-P

Answer 12

• polymerized to form glycogen (storage form of glucose)
• dephosphorylated to release glucose in the bloodstream
• converted to fatty acids via acetyl-CoA
• under oxidation via glycolysis, TCA cycle, and ETS to generate ATP
• enter the pentose phosphate pathway to yield 5-C pentose sugars and NADPH

Question 13

Liver converts fatty acids to…

Answer 13

• triglycerides
• phospholipids
• cholesterol and its esters for transport as plasma lipoproteins to adipose tissue for storage
• can also be oxidized to yield ATP or to form ketone bodies