integration of metabolism

Question 1

what is happening in the liver during
a post absorptive state (waking up)?

uptake?
glucose?
fat?

Answer 1

uptake:
fatty acid, alanine, glycerol and lactate uptake

glucose:
glycogenolysis / de novo glucogenesis (breaking down of glycogen to form glucose) and glucose release

fat:
triglyceride synthesis and fatty acid oxidation (breaking down to be used as energy)

Question 2

what is happening in the muscle in a post absorptive state?

glucose?
fat?
alanine?

Answer 2

glucose:
glucose uptake and glycogenolysis and glycolysis (glucose breakdown to produce energy)

fat:
triglyceride synthesis
fatty acid oxidation

alanine (used in protein construction):
transamination to create alanine and release of alanine

Question 3

what is happening in the adipose tissue in a post absorptive state?

what is being broken down?
released?

Answer 3

lipolysis (mobilise stored energy by breaking down triglycerides into fatty acids and glycerol)

fatty acid and glycerol release

Question 4

what is happening in the brain in a post absorptive state?

Answer 4

glucose uptake and glycolysis (breaking down of glucose to form energy)

Question 5

what is happening in the liver in a fed state (after a meal)?

glucose?
forming of fat?
protein?

Answer 5

glucose:

1. glucose uptake
2. glycogen synthesis (glucose molecules added to glycogen chain for storage)
3. glycolysis (breaking down of glucose to produce energy)
4. glucose release

fat:

1. lactate uptake
2. lactate conversion to pyruvate
3. pyruvate conversion to fat
4. fatty acid uptake
5. triglyceride synthesis
6. VLDL release

protein:

1. amino acid uptake
2. protein synthesis

Question 6

what is happening in the muscle in a fed state?

glucose?
fat?
protein?

Answer 6

glucose:
glucose uptake
glycolysis
glycogen synthesis

lactate release
fatty acid uptake
triglyceride synthesis

amino acid uptake
protein synthesis

Question 7

what is happening in the brain in a fed state?

glucose?
protein?

Answer 7

glucose uptake
glycolysis

amino acid uptake
protein synthesis

Question 8

what is happening in adipose tissue in a fed state?

glucose?
fat?
protein?

Answer 8

glucose uptake

fatty acid uptake
triglyceride synthesis (from fatty acids + glycerol)

amino acid uptake
protein synthesis

Question 9

what happens in the liver in an exercise state?

glucose?
fat?
uptake?

Answer 9

glucose:
glycogenolysis
gluconeogenesis (creating glucose from non-carb sources so fat and protein as means creating-new-glucose)
glucose release

fatty acid oxidation

glycerol, alanine and lactate uptake

Question 10

what happens in the brain in an exercise state?

Answer 10

glucose uptake

glycolysis

Question 11

what happens in the muscle in an exercise state?

glucose?
fat?
released?

Answer 11

glucose:
glucose uptake
glycogenolysis (glycogen to glucose)
glycolysis (glucose to energy)

fatty acid uptake

lactate, alanine and glycerol release

Question 12

what happens in adipose tissue in an exercise state?

Answer 12

breakdown of triglycerides (lipolysis)

fatty acid and glycerol release (products of triglyceride breakdown)

Question 13

what happens in the brain in a fasting state?

Answer 13

glucose uptake
glycolysis
ketone uptake

Question 14

what happens in the liver in a fasting state?

glucose?
ketones?
uptake?
fat?

Answer 14

gluconeogenesis (creating glucose from non-carb sources)
glucose release

ketone release

lactate, alanine and glycerol uptake to form glucose

fatty acid oxidation

Question 15

what happens in the muscle in a fasting state?

released?
fat?
glucose?

Answer 15

lactate, alanine (from protein and AA breakdown in muscle) and glycerol release

fatty acid uptake

glycogenolysis (glycogen to glucose)

Question 16

what happens in adipose tissue in a fasting state?

Answer 16

breakdown of triglycerids

fatty acid and glycerol release

Question 17

describe what ketogenesis is and when it occurs?

Answer 17

synthesis of ketone bodies

when it occurs (in response to fasting state as lack of glucose availability):
lack of insulin
high rates of lipolysis (breakdown of triglycerides) and fatty acid oxidation
accumulation of acetyl CoA
low rates of ATP demand and CHO flux

Question 18

how can ketone bodies be converted to acetyl-CoA?

what is the purpose of this?

where does this occur?

Answer 18

b-hydroxybutyrate to acetoacetate to acetoacetyl-CoA to acetyl-CoA

so can be used as fuels in muscle and liver and in starvation in brain

happens in the muscle and heart NOT liver