Week 2 summary

Question 1

Biochemical pathways are regulated by very precise control systems. What are these referred to as, and where in the pathways are they usually found?

Answer 1

Rate limiting enzymes - found early in metabolic pathway (activity regulated by modulators - inhibitors or stimulators)

Question 2

What does FIO2 and FICO2 stand for?

Answer 2

FIO2 - fraction of inspired oxygen (from environment)
FIO2 - fraction of expired CO2

Question 3

What is considered the classical or primary criterion for the identification of athletes VO2 max?

Answer 3

A plateau in VO2 despite increasing work rate.

RTQ - criteRION = one criteria not multiple (if asked in multiple choice)

Question 4

On a VO2 graph, where would you identify oxygen deficit on the graph?

Answer 4

At the start of the graph

EPOC would be the zone at the end of the graph

Question 5

During the rest-to-exercise transition ATP production increases immedietly and O2 uptake rapidly increases. How long does it take to reach steady-state?

Answer 5

1-4 minutes.
At steady state exercise primary ATP production processes are aerobic.

Question 6

Why do trained athletes have greater O2 uptake?

Answer 6

• Greater regional blood flow to active muscle
• Increased cellular adaptation and efficiency
• Increased mitochondrial volume in muscle fibres results in less lactate production at beginning of exercise.

Question 7

What contributes to the fast component of EPOC?

Answer 7

• Resynthesis of PC in muscle
• Restoration of muscle and blood O2 stores

Question 8

What contributes to the slow component of EPOC?

Answer 8

• lactate conversion to glucose
• elevated body temp
• post-exercise elevation of HR and breathing
• elevated hormones

Question 9

What are the 3 mechanisms of hormone action?

Answer 9

• activation of genes to alter protein synthesis
• activating ‘second messengers’ in the cell via G protein
• altering membrane transport

Question 10

Where is cortisol secreted from?

Answer 10

Adrenal Cortex

Question 11

Insulin release is inhibited during exercise so how does glucose get into the muscle cell?

Answer 11

Insulin stimulated glucose uptake occurs at rest.
During exercise there are a number of other mechanisms which stimulate GLUT4 translocation to membrane, main one being AMPK

Question 12

How does muscle act as a non-classical endocrine gland?

Answer 12

Interleukin 6 - both pro and anti-inflammatory. Produced during exercise promotes anti-inflammatory effects.

Question 13

Skeletal muscle produces myokines during contraction, what do these do?

Answer 13

• stimulate glucose uptake and FA oxidation.
• promote blood vessel growth in muscle.
• promote liver glucose production and TG breakdown.