Shared Flashcard Set

Details

Exercise Physiology Exam 1
Metabolism
74
Other
Not Applicable
01/09/2005

Additional Other Flashcards

 


 

Cards

Term
How does ATP release energy?
Definition
By hydrolysis of the high energy phosphate bond.
Term
What are the three mechanisms by which ATP can be resynthesized?
Definition
Phosphagen system, Glycolysis, Oxidative Phosphorylation
Term
What do we use the phosphocreatine stores for?
Definition
Quick bursts of energy, lasting 10 seconds or less. ie: golf swing, run to one end of the room
Term
Is phosphocreatine is stable source of energy?
Definition
No. That's why glycolysis is triggered at the onset of phosphocreatine use. Glycolysis is a more stable form of energy.
Term
What does resynthesis of phosphocreatine require? When does resynthesis occur?
Definition
Requires: ATP and O2 to resynthesize.
Occurs: only after activity, in the recovery phase.
Term
The biologic work done by the phosphocreatine system is also known as what?
Definition
Substrate level phosphorylation.
Term
Does the use of the phosphagen system require oxygen?
Definition
No, but resynthesis of phosphocreatine does.
Term
VOCAB: Oxidation
Definition
loss of electrons
Term
VOCAB: Reduction
Definition
Gain of electrons
Term
Is NADH the oxidized or reduced form of NAD+?
Definition
Reduced.
Term
VOCAB: Polysaccharide
Definition
3+ glucoses around a protein core
Term
Describe the type of energy carbohydrates are used for, vs. the type of energy lipids are used for.
Definition
CARBS: Fast energy, because carbs can be broken down quickly.
LIPIDS: Slow energy, it takes longer to break down a lipid.
Term
What are the two major sources of energy for our bodies?
Definition
Carbs and lipids
Term
VOCAB: Glycolysis
Definition
Breakdown of glucose or glycogen
Term
How many ATP will a single glucose molecule yield when it goes through glycolysis, only?
Definition
2
Term
What is the net yield of one glycogen molecule at the conclusion of glycolysis?
Definition
3ATP
Term
Which is faster? Carb or lipid metabolism? By how much?
Definition
Carb metabolization is 2xs faster than lipid.
Term
What is the only macronutrient that doesn't require O2 to generate ATP?
Definition
Carbohydrate
Term
VOCAB:Glycogenolysis
Definition
Breakdown of glycogen into glucose
Term
How much of the energy from carb catabolism is useable for activity?
Definition
30%. The other 70% is dissipated as heat.
Term
What are the important products of glycolysis?
Definition
Pyruvate, NADH
Term
What does NADH doe to pyruvate?
Definition
Turns it into lactate.
Term
Where does glycolysis occur?
Definition
In muscle sarcoplasm.
Term
Where is the ETC?
Definition
In the mitochondria
Term
What is PFK?
Definition
A rate-limiting enzyme used in glycolysis
Term
Where is pyruvate used?
Definition
In Krebb's cycle, it gets turned into Acetyl Co-A
Term
How does pyruvate get from muscle sarcoplasm to mitochondria?
Definition
It couples with carnitine, which facilitates transport into the mitochondria.
Term
Can substances other than carb catabolism products go through Krebb's Cycle?
Definition
Yes, Glycerol, amino acids and fatty acids from lipid catabolism can also go through Krebb's.
Term
What does Krebb's cycle provide?
Definition
Energy to the ETC, via NADH and FADH.
Term
Does Krebb's cycle directly require O2?
Definition
nope!
Term
What are the products of 1 pyruvate/acetyl co-a that goes through Krebb's?
Definition
1ATP, 3NADH, 1FADH, 1CO2
Term
Pyruvate can go through Krebbs, but it can also go to other places. Where else can pyruvate be used?
Definition
In the liver, where it is turned into glucose, and it can combine with NADH to make lactate.
Term
What does pyruvate combine with in Krebb's cycle to make Acetyl Co-A?
Definition
Oxaloacetate.
Term
What is the function of FADH and NADH?
Definition
They carry electrons to the ETC.
Term
How many ATP do you get from Krebb's cycle?
Definition
One.
Term
So .. what were the end products of Krebb's again? (It's important!)
Definition
1ATP, 3 NADH, 1FADH. Oh yes, and 1CO2.
Term
What is the final electron acceptor at the end of the ETC?
Definition
Oxygen. It combines with the 2e- and 2H+ to make H2O.
Term
How many NADH does glycolysis produce?
Definition
One.
Term
How many ATP do you get out of NADH from glycolysis that goes through the ETC? Why is this different from the number of ATP you get from the NADH product of oxidative phosphorylation?
Definition
2 ATP are produced from the NADH product of glycolysis. The NADH from oxidative phosphorylation makes 3 ATP in the ETC. This is because the NADH from glycolysis has to be transported into the mitochondria from the muscle sarcomere, whereas the oxidative phosphorylation NADH is already right in the mitochondria. So Glycolysis NADH enters the ETC at the same level as FADH, resulting in only 2ATP.
Term
If there is no O2 available at the end of the ETC, what happens?
Definition
There is no final resting place for the electrons, and the ETC will slow and eventually stop.
Term
Is the ETC an oxygen dependent system? How so?
Definition
Yes. It needs O2 to collect the electrons at the end of the chain, otherwise the chain will stop.
Term
How many ATP will the NADH from oxidative phosphorylation yield in the ETC?
Definition
Thrrrrreee!
Term
What regulates glycolylsis? (4major)
Definition
1. Concentration of enzymes. 2. Amount of substrate 3. Negative Feedback System 4. Glucose delivery to cells
Term
What enzymes help regulate glycolysis? (3major)
Definition
PFK, Hexase, Phosphorylase
Term
How does PFK regulate glycolysis?
Definition
It's a rate limiting enzyme that increases the speed of the reaction.
Term
How does Hexase regulate glycolysis?
Definition
It facilitates movement of glucose into the cell, and the breakdown of glucose into glucose-6-phosphate, which can either go through glycolysis or be turned into glycogen.
Term
How does phophorylase help regulage glycolysis?
Definition
It breaks glycogen down to make it useable in the pathway.
Term
How does the amount of substrate affect glycolysis?
Definition
Fuel needs to be present in order for energy production to occur. If glycogen or glucose is scarce, it limits the amount of reaction that can take place.
Term
Glycolysis is a negative feedback system. What things inhibit glycolysis?
Definition
ATP stores - when they're high, glycolysis is inhibited because we can only store so much ATP. Creatine - but I don't know why. If you do, please let me know. Citrate - the body knows we have enough when this is present. When pH is low - because when things get acidic, it means we have a lot of H+ and glycolysis stops because H+ isn't being collected at the end of the ETC.
Term
Glycolysis is a negative feedback system. What things stimulate glycolysis?
Definition
AMP, ADP (if we have lots of ADP, the body wants to turn it into ATP), Pi and increased pH
Term
Where is the Glut4 Transmitter located?
Definition
Sarcolemma - in muscle and fat tissue.
Term
Why is lactate a good thing?
Definition
If Krebb's cycle and the ETC aren't running quickly enough, the NADH from glycolysis will not get the H+ removed from it. As a result it will combine w/ pyruvate to make lactate, which then leaks out of the cell. Without lactate, the ETC process would stop completely.
Term
What happens to lactate once it is formed?
Definition
It leaks from the cell and gets carried to liver where it is turned into glucose.
Term
How is lactate used as an energy source? (2 major ways)
Definition
In the recovery phase, NAD scavenges electrons from lactate to make NADH to go to the ETC. The pyruvate is then used to produce glucose via the Cori cycle in the liver. Lactate is also produced in fast twitch cells and is shuttled to other muscle cells, where it can be converted into pyruvate for krebb's cycle.
Term
Is protein catabolism done aerobically or anaerobically?
Definition
Aerobically only.
Term
When is protein used as an energy source?
Definition
During long endurance activity, and heavy training. It will also be used in the absence of other substrate (fat, or carb) but it is never a primary choice for energy.
Term
There are three ways that amino acids (proteins) can be used for energy. what are they?
Definition
Direct entry into Krebb's Cycle, Converstion to pyruvate which --> glucoes which --> glycolysis, and conversion to acetyl co-a.
Term
VOCAB: Deamination
Definition
breakdown of amino acids by taking away the amine and leaving you with acids.
Term
What are triglycerides composed of?
Definition
Free fatty acids and glycerol.
Term
How do we get energy from FFA?
Definition
They are turned into acetyl co-a to be used in krebb's.
Term
Is fat catabolism aerobic or anaerobic?
Definition
Aerobic only.
Term
What is the most plentiful source of potential energy?
Definition
Stored lipids.
Term
What has a higher energy yield than carbs?
Definition
lipids.
Term
What are the lipid energy sources? (where do we get the lipids from that we use for energy?) (3 major places)
Definition
1. Triglycerides in muscle tissue, 2. Circulating triglycerides, 3 Circulating FFAs (mobilized from triglycerides in adipose tissue.
Term
How many FFAs do you get from the breakdown of 1 triglycerid?
Definition
Thrrreeee!
Term
Through what process are fatty acids converted to acetyl Co-A?
Definition
Beta Oxidation.
Term
VOCAB: Beta Oxidation
Definition
The process by which FFAs are converted to acetyl co-a to enter krebs
Term
How do we get energy from glycerol?
Definition
It enters glycolysis and replaces 3 phosphoglyceraldehyde. It is a slow process, and we don't get much energy from it.
Term
How is fat metabolism stimulated?
Definition
Exercise and decreased intracellular FFA.
Term
How does exercise increase fat metabolism?
Definition
Increases epinephrine, norepinephrine, glucagons, growth hormone, and these increase lipase via cAMP.
Term
What things inhibit fat metabolism? (3) And how do they do it? (1 explanation for all 3 regulators)
Definition
Insulin, lactate and ketones inhibit fat metabolism via inhibition of cAMP.
Term
What yields more net energy, in terms of calories? Carbs or lipids?
Definition
Lipids. (9Cal vs 4Cal)
Term
Where does beta oxidation occur?
Definition
In the mitochondria
Term
What is the product of beta oxidation? what happens to it?
Definition
2H+. they go to the ETC.
Supporting users have an ad free experience!