Metabolism during exercise Flashcards
What is Respiratory Quotient?
RQ = CO2 produced / O2 consumed
What is the RQ of carbs?
1
What is the RQ of fats?
0.7
Metabolism of fat consumed more oxygen than carbs
If an animal has an RQ of 0.75, what is its energy source?
Lipid
What are the vital energy needs
Physical, emotional, digestive
What will increase basal metabolism
Muscle mass, hyperthyroidism, fever
If a dog eats 1% above needed energy intake each year how many extra pounds is that in 12 years?
30 lbs
What has the highest energy requirement?
Resting metabolic rate
What has the second highest energy requirement?
Exercise
What has the lowest energy requirement?
Thermoregulation
Does untrained muscle require a higher or lower respiratory quotient?
Lower. More FA are used in trained individuals and more glucose in untrained
What is the immediate energy system
ATP, Creatine phosphate, Adenylate Kinase
How long can ATP sustain exercise?
3 seconds
How is ATP involved in muscle contraction?
ATP disconnects actin from myosin
Is lactate formed at all intensities?
Yes
Does trained or untrained muscle have a slower increase in lactate?
Trained
A rest, what is lactate oxidation? During exercise?
50%, 75%
What tissues can utilize lactate?
Heart, Skeletal, Muscle, Brain
How many Lactate DH isoforms are there?
5.
Different organelles within the same cell can have different isoenzymes
Why does glycogen produce 3 ATP and glucose only 2?
Glycogen enters as G6P and does not need hexokinase
How many ATP are produced from a glycogen molecule in a Type IIb tissue?
31
What energy type is used during moderate exercise?
Carbs more than fat
50-75% VO2max
Theory behind glycogen loading?
Deplete glycogen stores then overcompensate which leads to increased performance
What is hitting the wall?
When muscle glycogen runs out of OAA, fatty acids must be used as fuel. FAs are metabolized at half the rate of glycogen so marathoners slow down drastically
What is the final kick?
High levels of Acetyl CoA (B-ox) can downregulate PDH which spares some glyocgen. If there is enough left, can be used at the end of a race
How long can aerobic (B-ox)energy last?
As long as supplies last
What energy system would be used for low intensity / long duration exercise?
Aerobic
Physiologic benefits of training
Increased O2 uptake by muscles
Increased blood vessel size
Increase in mitochondria # and size
Increased glycgen storage
What organ adds arythrocytes during exercise?
Spleen
Where is creatine produced?
Liver and kidney
Used in the muscle
