Chapter 2 Flashcards
What is the only macronutrient that can be oxidized anaerobically?
Carbohydrates
ATP stores
80-100g at one time, some ATP is always necessary for cellualr functions so it cannot be depleted. During muscle fatigue ATP may only be able to decrease 50-60%
Individuals with more type 2 of type 1 fibers can replinish ATP faster?
type 2.
Myokinase Reaction
aka Adenylate Kinase. 2ADP is changed to ATP + AMP with the enzyme adenylate kinase
Law of mass action/mass action effect
Concentrations of reactants or products in a solution will drive the direction of the reactions. Example: as ATP is hydrolized to create energy there is an increase in ADP and Pi. This will increase the rate of creatine kinase and adenylate kinase reactions until intensity is low enough to avoid depleting CP stores.
Glycolysis
breakdown of carbohydrates (glycogen stored in the muscle or glucose in the blood) to re-synthesize ATP. The end result is pyruvate and it can go in 2 directions. The pyruvate can be converted to lactate or the pyruvate can be shuttled into the mitochondria.
Anaerobic Glycolysis (fast glycolysis)
Converting pyruvate to lactate which causes ATP resynthesis to occur at a faster rate but is limited in duration.
Aerobic Glycolysis (slow glycolysis)
When pyruvate shuttled into the mitochondria to the Krebs Cycle ATP resynthesis occurs at a slower rate but can occur for a longer duration.
What are the 3 ways that lactate can be cleared?
- by oxidation within the muscle fiber where it was produced.
- can be transported in the blood to other muscle fibers
- transported in the blood to the liver where it’s converted to glucose. (cori cycle)
Lactate clearnce rates
lactate concentrations normally return to a pre-exercise value an hour after activity. light activity during the post-exercise period can increase lactate clearnce rates.
Peak blood lactate concentration
occurs approximately 5 minutes after exericse
What happens to pyruvate if there is enough oxygen in the mitochondria
The pyruvate is transported to the mitochondira. NADH is also transported to the mitochondria. When pyruvate enters the mitochondria it is converted to a Acetyl CoA. This Acetyl CoA enters the Krebs cycle for further ATP resynthesis. NADH enters the electronic transport chain where they are used to re-synthesize ATP
Phosphagen System
- Percent of Maximum Power
- Typical exercise time
- range of work to rest period ratios
- 90-100%
- 5-10 seconds
- 1:12 to 1:20
Fast Glycolysis System
- Percent of Maximum Power
- Typical exercise time
- range of work to rest period ratios
- 75-90%
- 15-30 seconds
- 1:3 to 1:5
Fast Glycolysis and Oxidative
- Percent of Maximum Power
- Typical exercise time
- range of work to rest period ratios
- 30-75%
- 1-3 minutes
- 1:3 to 1:4
Oxidative
- Percent of Maximum Power
- Typical exercise time
- range of work to rest period ratios
- 20-30%
- > 3 minutes
- 1:1 to 1:3
Two primary mechanisms for re-synthesizing ATP
- Substrate level phosporylation - direct synthesis of ATP from ADP during a single reaction
- Oxidative phosphorylation - resynthesis of ATP in the electron transport chain
phosphorylation def
adding inorganic phosphate to another molecule. (So like when you have ADP + P = ATP. This is the phosphorylation of ADP to ATP
How is glycolysis stimulated?
high concetnrations of ATP, Pi, ammonia and by a slight decrease in pH and AMP
How is glycolysis inhibited?
by lower pH, ATP, CP, citrate, and free fatty acids
Allosteric inhibition
when an end product binds to regulatory enzyme and decreases turnover rate and slows product formation
Allosteric activation
when and “activator” combines with the enzyme and increases the turnover rate
Lactate Threshold definition
1. when does it begin
the exercise intensity or relative intensity where the blood lactate begins an abrupt increase above the baseline concentration
1. lacate threshold typically begins at 50% to 50% of maximal oxygen uptake in untrained individuals and 70% to 80% in trained athletes.
Onset of blood lactaet accumulation
a second increase in the rate of lactate accumulation which occurs when the concentration of blood lactate reaches 4 mmol/L
Oxidate system
is the primary source of ATP at rest and during low intensity activity, and uses primarily carbohydrate and fat as substrates.
Where is ATP from at rest?
70% is derived from fats and the other 30% is from carbohyrates.