Integration of Metabolism Flashcards
what metabolism does muscle tissue rely on?
Carboyhydrate + fatty acid oxidation
which tissues cannot utilise fatty acids as a fuel?
brain and nervous tissue
what does hypoglycaemia cause?
faintness and coma
what does hyperglycaemia cause?
irreversible organ damage
what substrate does the brain metabolise mostly even in the fasting state?
glucose
In skeletal muscle, what occurs during vigorous contraction?
Oxygen becomes limiting factor
glycogen breakdown in muscles
lactate formation
what is the heart designed for?
complete aerobic metabolism - rich in mitochondria
what substrates does the heart use?
from the TCA cycle:
ketone bodies
free fatty acids
what does loss of oxygen supply to the heart lead to?
cell death + myocardial infarction
what is the normal glucose range?
4-5.5mM
what is a key role of the liver?
glucose storage organ (glycogen)
plays a key role in lipoprotein metabolism (transport of triglycerides + cholesterol)
during fasting, what does acetyl CoA turn into?
ketone bodies
what can excess glucose-6-phosphate be used to generate?
glycogen in the liver and muscle
what happens to excess acetyl CoA?
fatty acids, stored in the adipose tissue
what is produced during extreme exercise?
lactate
what molecules are involved in gluconeogenesis?
lactate - utilised to regenerate pyruvate by lactate dehydrogenase
amino acids - can be derived from the diet or breakdown of skeletal muscle
glycerol backbone - used to generate DHAP
what happens when blood conc goes below 3mmol (hypoglycaemia)?
breakdown liver glycogen stores
release fatty acids from adipose tissue
convert acetyl CoA into ketone bodies via the liver
when does gluconeogenesis tend to happen?
when the rate of glycolysis exceeds the rate of the TCA cycle
what are glucogenic amino acids used to generate?
glucose via gluconeogenesis
what are ketogenic amino acids used to generate?
fatty acids + ketone bodies
what 2 things does contracting muscle require? (aerobic respiration)
more ATP
more glucose transporters on the membrane of muscle cells
how does adrenaline help increase the rate of glycolysis in muscle? (aerobic respiration)
increase gluconeogenesis by the liver
increase the release of fatty acids from adipocytes
what does lactate synthesis do during anaerobic respiration?
replenish NAD+ levels, enabling glycolysis to continue
lactate also used in gluconeogenesis to synthesise more glucose
