Metabolism

Question 1

micronutrients and uses

Answer 1

Vitamins: coenzymes, antioxidants, ligands for hormone receptors
Minerals: bone mineralization, muscle contraction, production of ATP, enzyme & protein cofactors, cellular transport

Question 2

macronutrients

Answer 2

Carbs- energy, energy stored a glycogen- more hydrated than TAGs

Protein- protein synthesis, carbons for glucose synthesis

Fat- energy, absorption of fat soluble vitamins, prostaglandin synthesis, components of cell membrane, energy stored as triacylglycerols

Question 3

Fed state liver

Answer 3

insulin stimulates

1. glucose storage via glycogenesis
2. oxidation via glycolysis
3. FA synthesis to TAGs and VLDL adipose storage

Question 4

Fed state muscle

Answer 4

insulin stimulates

1. Glucose transport into muscle cells
2. Amino acids transported to muscle cells
3. Amino acids to protein synthesis
4. Glucose to glycogensis
5. Glucose to glycolysis

Question 5

Fed state adipose

Answer 5

insulin stimulates

1. Glucose transport to adipocytes
2. VLDLs (from liver) and chylomicrons (from gut) to FAs to TAGs
3. Glycolysis which produces ATP

Question 6

Brain Fed state

Answer 6

Insulin has no effect

1. Glucose transported into cells undergoes glycolysis
2. Same for RBCs

Question 7

Liver fasting

Answer 7

glucagon stimulates

		1. Glucose from glycogen: glycogenolysis 2. Glucose from other sources: gluconeogenesis 3. FAs transported to liver from adipose, can be converted to ketone bodies, VLDLs or used for ATP via beta oxidation

Question 8

Muscle fasting

Answer 8

Glucagon has no effect, determined by substrate availability

1. Depends on ketone bodies, FAs, and VLDLs as energy source
2. FAs and Ketones undergo beta oxidation
3. Protein degradation AAs to liver for gluconeogensis

Question 9

Adipose fasting

Answer 9

glucagon stimulates

1. Lipolysis- degradation of stores
2. FAs to oxidation or FAs for other organs for fuel

Question 10

Brain fasting

Answer 10

Glucagon HAS NO EFFECT

1. Brain can use ketone bodies through oxidation (ketolysis) and glucose

Question 11

RBCs

Answer 11

only use glucose (no mitochondria)

Question 12

starvation vs fasting

Answer 12

Starvation: liver glycogen stores only last 24 hours so no more glycogenolysis,
Gluconeogenesis is only source of blood glucose

Fasting: equal circulating levels of fatty acids & ketone bodies
muscle uses both ketone bodies & fatty acids for fuel

Starvation: increase in circulating levels of ketone bodies vs fatty acids
ketone bodies used by brain (still uses some glucose)
muscle switches to fatty acids for fuel (saves KB for brain)

Question 13

high glucose hormone

Answer 13

= fed state= insulin secreted

Question 14

low glucose hormone

Answer 14

= fasting or starvation = glucagon secreted