Lecture 14

Question 1

what is the primary transporter for glucose into the muscle cytoplasm

Answer 1

GLUT 4

Question 2

what is the first step of the citric acid cycle (formation of citric acid)

Answer 2

oxaloacetate combines with Acetyl CoA to make citric acid

Question 3

what is needed to form oxaloacetate

Answer 3

pyruvate

Question 4

what are fats stored as and what do they need to be split into

Answer 4

stored as triglycerides so they need to be split into glycerol and free fatty acids

Question 5

where do fatty acids need to be carried after they are split from glycerol and what happens to them there

Answer 5

must be carried into the mitochondria and then go through B oxidation

Question 6

Where will the Acetyl CoA that is formed during B oxidation enter into

Answer 6

the citric acid cycle

Question 7

why does fat metabolism still require some ongoing CHO metabolism

Answer 7

because pyruvate is still needed to form oxaloacetate

Question 8

where are triglycerides stored in the body

Answer 8

mostly in adipose tissue, small amount in intramuscular triglycerides

Question 9

hormone sensitive lipase is needed for ….

Answer 9

fatty acid to be broken off from glycerol molecule

Question 10

mobilisation of fats depends on adipose tissue blood flow, is this increased or decreased during moderate and high intensities

Answer 10

moderate (~50% of VO2 max) = increased

high intensity = decreased

Question 11

what hormones stimulate fat mobilisation

Answer 11

adrenaline and noradrenaline

Question 12

how is hormone sensitive lipase activated

Answer 12

adenylate cyclase (stimulated by hormones) will convert ATP to c AMP

that will active protein kinase

and activate hormone sensitive lipase

Question 13

how are fatty acids translocated into the mitochondria

Answer 13

enzymatic transport system using carnitine

Question 14

what happens to free fatty acids during B oxidation

Answer 14

FFA is progressively broken down (hydrolysed),

producing Acetyl CoA and reducing equivalents

Question 15

what happens to protein metabolism during exercise

Answer 15

degradation = catabolic

Question 16

what ideally happens to protein metabolism post exercise

Answer 16

providing you are resting and have essential amino acids available = anabolic

Question 17

is sweat urea nitrogen found to be greater or lower on low CHO diet compared to high CHO diet or vice versa

Answer 17

low CHO diet = high sweat urea nitrogen

high CHO diet = lower sweat urea nitrogen

Question 18

can fatty acids be used to generate glucose

Answer 18

no (they are not a source for gluconeogenesis)

Question 19

how does the source of energy e.g glucose and triglycerides change over time with exercise

Answer 19

beginning = muscle triglycerides and muscle glycogen

as time goes on = plasma free fatty acids and blood glucose

Question 20

what does training (depleting stores) do to the amount of glycogen stored

Answer 20

depleting stores increases the amount stored

Question 21

what is supercompensation

Answer 21

after exercise because of muscle glycogen repletion you are able to store more than what was there pre exercise

Question 22

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)

Answer 22

• 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