1.5 Integration Of Metabolism

Question 1

What does muscle metabolise

Answer 1

Carbohydrate and fatty acid oxidation

Question 2

What does the brain metabolise

Answer 2

Glucose (ketone bodies if needed)

Can’t utilise fatty acid

Question 3

What does the heart metabolise

Answer 3

Fatty acids and carbs

Question 4

Too little glucose

Answer 4

Hypoglycaemia

Causes faintness and coma

Question 5

Too much glucose

Answer 5

Hyperglycaemia

Can cause irreversible damage

Question 6

ATP requirement in skeletal muscle

Answer 6

Light contraction is met by oxphos

Vigorous contraction uses glycogen breakdown and lactate formation

Question 7

Metabolic features of the heart

Answer 7

Completely aerobic metabolism
Rich in mitochondria
Utilises TCA cycle substrates (free fa and ketone bodies)

Question 8

What levels should glucose be kept at

Answer 8

4-5.5mM

Question 9

Glucose storage organ

Answer 9

Liver (glycogen)

Question 10

During fasting Acetyl coA

Answer 10

Doesn’t enter TCA cycle but makes ketone bodies

Question 11

Gluconeogenesis

Answer 11

Formation of glucose from pyruvate

Question 12

Inputs to gluconeogenesis

Answer 12

Lactate from skeletal muscle converted to pyruvate by lactate dehydrogenase

Amino acids from diet or skeletal muscle

Glycerol converted to DHAP (triglyceride hydrolysis)

Question 13

How is gluconeogenesis possible as the reversal of glycolysis

Answer 13

Energetically unfavourable so 6 bypass reactions (breaking of phosphoanhydride bonds to make it energetically favourable

Question 14

Protein as fuel courses

Answer 14

Glucogenic amino acids generate glucose via gluconeogenesis

Ketogenic amino acids generate fatty acids and ketone bodies

Question 15

Fats as fuel sources

Answer 15

Triglycerides broken down to fatty acids and glycerol

Fatty acids to ketone bodies

Enter gluconeogenesis

Question 16

What can increase rate of glycolysis in muscles (aerobic)

Answer 16

Adrenaline

Question 17

How does adrenaline increase glycolysis

Answer 17

Increase gluconeogenesis by liver

Increase release of fatty acids

Question 18

How is nad+ replenished in anaerobic respiration

Answer 18

Lactate synthesis

Question 19

Km

Answer 19

Michaelis constant

Question 20

Michaelis constant mk

Answer 20

Concentration of substrate when an enzyme functions at a half maximal rate

Question 21

What is secreted when glucose levels rise

Answer 21

Insulin

Question 22

Insulin

Answer 22

Stimulates uptake, storage and use of glucose

Question 23

What is secreted when glucose levels fall

Answer 23

Glucagon

Question 24

Glucagon

Answer 24

Stimulates production of glucose by gluconeogenesis and breakdown of glycogen and fat

Question 25

Glucocorticoids function

Answer 25

Increase synthesis of metabolic enzymes with glucose availability

Question 26

Adrenaline effect on glucose

Answer 26

Strong and fast mobilise glucose

Question 27

Where is insulin secreted from

Answer 27

Pancreas

Question 28

Hormonal control of glucose fasting

Answer 28

Inc glucagon, dec insulin

Stimulates glucose production in liver (glycogen breakdown and gluconeogenesis)

Fatty acid breakdown

Adrenaline stim glycogen breakdown, glycolysis and lipolysis

Question 29

Prolonged fasting

Answer 29

Adipose tissues hydrolyse triglycerides for fa

TCA cycle intermediates provide substrates for gluconeogenesis (dec in amount)

Protein breakdown for a for gluconeogenesis

Ketone bodies produced from fa and a for brain

Question 30

T1dm

Answer 30

Failure to secrete enough insulin (B cell dysfunction)

Question 31

T2dm

Answer 31

Insulin resistance

Failure to respond appropriately to insulin levels

Question 32

Complications of diabetes

Answer 32

Hyperglycaemia
Hypoglycaemia
Cardiovascular complications
Ketoacidosis