Chapter 1 Flashcards
How much glucose in the liver at one time?
100 grams
In the morning, without having eaten anything, what would your glycogen levels be in the liver?
Around 0 grams
If you are training hard, and you have a high carb diet, your glycogen levels would be about what?
Higher than 100 grams
What is glycogen’s main function?
Keep plasma constant
What is the plasma glucose concentration based on normal eating?
80 to 100 mg/dl or 4-5mmol/L
1mmol/L is how many mg/dl?
18
When will you drop down to hypoglycemic levels in your plasma glucose?
When you’ve had a more active day (under exercise conditions) and during high glycemic index CHO intake
What value is considered hypoglycemic levels?
45mg/dl and less
Why does the brain rely on blood glucose?
In order for it to break down to ATP and get the necessary energy to think and work properly.
What happens to the brain when there is not enough circulating blood glucose?
Will become nauseous, dizzy, syncope, falling asleep…
What happens when blood (red blood cells) consume glucose?
Turns it into lactic acid.
Which are the only 2 that use blood glucose exclusively?
Brain and blood
What happens if the heart doesn’t get its normal blood glucose level?
It will use fat and lactic acid as energy source…
Muscle glycogen can be broken down into what?
Pyruvate and then lactic acid.
How much muscle glycogen is in the body?
400g
How much plasma glucose is in the body? (grams)
3g
If you’re just sitting in class (no major activity), you are storing glycogen. So what are the processes that happen?
G(plasma) –> glycogen
If doing activity, body recruits and breaks down glycogen for energy. What are the processes that happen in the body?
G(plasma) –> pyruvate –> lactic acid.
If you have a high carb diet, what percentage of your diet is made up of CHO?
50-75%
If you have a high carb diet, how many grams of carbs are stored?
Over 400 grams
If you’re following a low carb diet, how many grams of carbs are stored?
Less than 400 grams
When you are training aerobically, which enzyme helps to make glycogen in the muscle?
Glycogen synthase
Diet and training combined will increase carb storage to?
up to 600-800 grams within the tissue.
Is more grams of CHO stored better or worse for the body and why?
Better. The more carbs you have th emore you can call up on them to be used when you need it.
Does glucose leave the skeletal muscle?
Never
Glucose in the skeletal muscle is either ________ or ________.
Stored or used.
Does glucose leave the liver?
Yes!!!
Would you get more energy from 1 g fat or 1 g carb?
1g fat.
What are the 2 negative effects of using fat for energy?
1) It takes longer to break down a fatty acid (time). 2) Need to consume more oxygen for a fat than a carb.
What is the relationship between oxygen consumption and fat?
The more oxygen you consume, the more fat you can combust.
If you have a low oxygen consumption, what happens to your fat?
They’re not touched in the storage because you’re not stressing the system enough to get them!
During mild exercise (25% of VO2 max), explain what happens to the glycogen in your body.
Will get some glycogen to turn into glucose to go towards muscle for activity.
O2 consumption is enough so mitochondrion helps you to provide energy.
During moderate exercise (50-65% of VO2 max), explain what happens to the glycogen in your body.
Glycogen recruited more, more glucose, and taken up by the muscle for activity.
Greater demand to consume O2 (which you cannot provide, only to a certain point). Mitochondria does not provide you with any more oxygen, so what happens is that you will make large forms of lactic acid, because you cant supply mitochondria to oxidize.
During intense exercise (75-90% of VO2 max), explain what happens to the glycogen in your body.
Glycogen recruited even more, more glucose and take to the muscle for activity.
Greater demand of O2 for you to provide (which you cannot provide, only to a certain point). Mitochondria does not provide you with any more oxygen, so what happens is that you will make large forms of lactic acid, because you cant supply mitochondria to oxidize.
As intensity exercise increases, what happens to the amount of glucose released from the liver?
It increases
As exercise intensity increases, uptake of glucose does what?
Increases
Are you always using all three sources of substrate: carbs, fat, protein?
Yes. Always!!!
When hormones bind to the liver, what happens?
They break down glycogen.
As exercise intensity increases, is there an increase or decrease in hormonal release and binding?
Increase
A glycerol base is also known as…
glucose-3-phosphate
What is a triglyceride made up of?
A glycerol base and 3 fatty acids.
What is the term for triglyceride synthesis?
Esterification
Explain esterification.
When glucose breaks down it goes to G6P then either becomes G3P or pyruvate. Then, the G3P made (glycerol base) binds to the fatty acids that are already bound inside the adipose tissue for storage.
Hw many adipose sites are there for an 80kg individual?
12,000g
If you walk a really far distance, would you use up all of your adipose storage?
No never, will still have plenty to do the activity again.
Which enzyme is involved in triglyceride breakdown?
Hormone sensitive lipase
What is the other term for triglyceride breakdown?
Lipolysis
What is hormone sensitive lipase’s function?
Serves to break the connections between FA and glycerol base.
What doe the fatty acids (2 things) do once they’re free from the glycerol base?
1) reconvert back, 2) leaves the adipose, convert to protein, attaches to the albumin in blood for transport to the rest of the body as FFA.
What happens when norepinephrine, epinephrine and GH come to lipase?
Lipase gets sensitive and is more likely to give more FFA away so that there’s more in the plasma that hooks up with the albumin and take it all over the body.
What is the equation for respiratory quotient?
RQ = volume of CO2 gas produced/volume of oxygen consumed
What is the textbook RQ for carbs?
1
Is the textbook RQ for carbs realistic?
No
For carbs, what does the RQ ratio look like?
6/6
What is the textbook RQ for saturated fatty acids?
Roughly 0.7
What is probably the most abundant fatty acid in your system right now?
Palmitic acid
What does the RQ equation look like for FA?
16/23
Why is the RQ for fats and carbs unrealistic?
Because the value means that they are only burning that substrate. So a value of 1, means you’re only burning carbs solely. And a value of 07, means that your’e only combusting fats. This is unrealistic because they cant solely combust one thing.
What is the actual normal value for RQ for us?
0.8
As exercise gets longer, what happens to the RQ value?
Decreases gradually
What happens to your fats and carbs (RQ) when your exercising for longer and longer?
The percentages change.
At around 6 hours, which substrate is the body using more: fat or carb? And why?
Fat, because you’re probably consuming a lot of FFA and very little carbs are left to supply you during the activity.
What is the explanation behind it costing more to combust a fat than a carb?
Because you need 23 moles of oxygen to completely oxidize a fat. So, you need to consume more oxygen to be able to ACCESS the FFA (you have plenty but need o2 to take it).
RQ value basically mainly depends on one important factor… which is…
oxygen! Depends on your capabilities to get enough oxygen in order to oxidize something.
Which is more important to achieve ATP: carbons or hydrogens? Why?
Hydrogens, because they pass through the ETC (mito) to give us oxygen.
What is deamination?
Breaking down of amino acid
What happens during deamination?
Amino acid loses NH2 group and turns into carbohydrate. The process forms urea, which the liver wants to get rid of, so sends it to the kidney to be excreted as urine. The carb that was just formed now goes to the skeletal muscle for energy!
The more exercise, the ________ urea is excreted.
More
Urea leaves the body in which 2 forms?
As urine or as sweat.
What is transamination in brief?
The making of amino acid
Explain transamination.
Glutamate (a.a) (which is taken up by the liver) gives its NH2 to pyruvate (carb) to form alanine (a.a). And the glutamate that gives up its NH2 ends up becoming alpha keto-glutamic acid (carb) which will find its way back to the kreb cycle as a carb.
What is alanine good for?
Building muscle or energetics imp.
