energy system responses Flashcards
What 3 energy systems does the body rely on?
-ATC-PC system
-Lactate system
-Aerobic system
How does the body use energy from food?
The body extracts energy from food carbs, fat and protein to produce ATP
What is phosphate creatine?
A high energy compound stored in cells which is used to help short explosive physical efforts
What is the most concentrated source of energy?
-Fat, providing 2x as much as carbs or protein.
-During exercise fat is broken down into fatty acids and transported through blood to muscles as fuel.
-Slower than carb process
What is protein used for?
To build, maintain and repair body tissues
What does ATP consist of?
a base and three phosphate groups
How is ATP formed?
By a reaction between an ADP molecule and a phosphate molecule
what happens when a molecle of atp is used
When a molecule of ATP is used, the last phosphate group splits off and energy is released
What is the ATP-PC system made up of?
ATP and creatine phosphate
What happens in the ATP-PC system?
-PC is broken down releasing one phosphate molecule
-This phosphate molecule is used rebuild ATP
-The enzyme controlling the breakdown of PC is called creatine kinase
Is the ATP system anaerobic?
Yes, it can operate with or without oxygen
During the first 5 seconds of exercise, ATP-PC is relied on. How long can the ATP-PC system sustain exercise for?
3-15 seconds. If activity continues beyond this period, the body must rely on additional energy
What is glycolysis and what happens during it?
-The term used to describe the breakdown of glucose
-Consists of enzymatic reactions
-End product is pyruvate which is used in the krebs cycle or converted to lactic acid
When does anaerobic glycolysis occur and what happens during it?
occurs when energy is required during no oxygen
it involves the breakdown of glycogen to form ATP plus lactate
How does the aerobic energy system work?
-Uses carbohydrates, fats and proteins extracted from the diet to resynthesise ATP
-This system produces more ATP than anaerobic energy system but at a slower rate so therefore its less suitable for intense exercise
-Consists of 3 stages
What is the first stage of the aerobic energy system?
-Aerobic glycolysis
-Converts stored glycogen to glucose
glucose is broken down by enzymes in presence of oxygen
-2 ATP molecules are used to fuel glycolysis and 4 are created, resulting in gain of 2 ATP molecules for use in muscle contration
pyrivate is created
pyruvate converted into acetyl coenzyme. can be synthesised to create more atp
What is the 2nd stage of the aerobic energy system?
krebs cycle
1 acetyl coenzyme A enters Krebs cycle
2 acetyl coenzyme A is broken down into carbon dioxide
and hydrogen ions
3 2 ATP are synthesised and made available to fuel
muscle contraction
4 hydrogen ions are transferred to the electron transport
chain
What is the 3rd stage of the aerobic energy system?
1 hydrogen ions from the Krebs cycle are carried to the
electron transport chain by carrier molecules
2 hydrogen ions undergo a series of chemical reactions
3 a hydrogen ion gradient is created – as hydrogen ions
move across this gradient adenosine diphosphate (ADP)
is phosphorylated (adds another phosphate group) to
form ATP
4 water is created as a by-product.
what is obla
is the level abovewhich blood lactate is produced fasterthan it can be used. it occurs when te concentraton of blood lactate reaches 4mmol/c . continuedexercise above results causes accumlation of hydrogen ions in muscle tissues, causing fatigue and pain.
