Lecture 14 Flashcards
Fuelling Exercise
what is the primary transporter for glucose into the muscle cytoplasm
GLUT 4
what is the first step of the citric acid cycle (formation of citric acid)
oxaloacetate combines with Acetyl CoA to make citric acid
what is needed to form oxaloacetate
pyruvate
what are fats stored as and what do they need to be split into
stored as triglycerides so they need to be split into glycerol and free fatty acids
where do fatty acids need to be carried after they are split from glycerol and what happens to them there
must be carried into the mitochondria and then go through B oxidation
Where will the Acetyl CoA that is formed during B oxidation enter into
the citric acid cycle
why does fat metabolism still require some ongoing CHO metabolism
because pyruvate is still needed to form oxaloacetate
where are triglycerides stored in the body
mostly in adipose tissue, small amount in intramuscular triglycerides
hormone sensitive lipase is needed for ….
fatty acid to be broken off from glycerol molecule
mobilisation of fats depends on adipose tissue blood flow, is this increased or decreased during moderate and high intensities
moderate (~50% of VO2 max) = increased
high intensity = decreased
what hormones stimulate fat mobilisation
adrenaline and noradrenaline
how is hormone sensitive lipase activated
adenylate cyclase (stimulated by hormones) will convert ATP to c AMP
that will active protein kinase
and activate hormone sensitive lipase
how are fatty acids translocated into the mitochondria
enzymatic transport system using carnitine
what happens to free fatty acids during B oxidation
FFA is progressively broken down (hydrolysed),
producing Acetyl CoA and reducing equivalents
what happens to protein metabolism during exercise
degradation = catabolic
what ideally happens to protein metabolism post exercise
providing you are resting and have essential amino acids available = anabolic
is sweat urea nitrogen found to be greater or lower on low CHO diet compared to high CHO diet or vice versa
low CHO diet = high sweat urea nitrogen
high CHO diet = lower sweat urea nitrogen
can fatty acids be used to generate glucose
no (they are not a source for gluconeogenesis)
how does the source of energy e.g glucose and triglycerides change over time with exercise
beginning = muscle triglycerides and muscle glycogen
as time goes on = plasma free fatty acids and blood glucose
what does training (depleting stores) do to the amount of glycogen stored
depleting stores increases the amount stored
what is supercompensation
after exercise because of muscle glycogen repletion you are able to store more than what was there pre exercise
what are the adaptations that occur due to training which allow for a greater rate of energy provision and duration and a given intensity (7)
- increases in circulation
- increases in mitochondria
- increased stored substrates
- increases in receptor sensitivity (e.g to hormones)
- increases in enzymes specific to energy systems
- hormonal changes
- increases in membrane transporter molecules
