LEWIS: Anaerobic energy systems Flashcards Preview

A2 PE > LEWIS: Anaerobic energy systems > Flashcards

Flashcards in LEWIS: Anaerobic energy systems Deck (16):
1

Energy system that the body uses to resynthesise ATP is dependent on the

intensity of work being carried out

2

ATP breakdown and resynthesis is a

coupled reaction

3

more intense the exercise = the more ATP used to provide energy for muscle fibre contraction, and therefore more ATP we need to

resynthesise

4

2 anaerobic energy systems:

ATP-PC
Lactic acid

5

(ATP-PC) phosphocreatine is an energy rich compound that when broken down releases energy to resynthesise

ATP

6

ATP-PC equation:

PC-(creatine kinase)->P+C+ENERGY ) (exothermic)
V
ATP<-P+ADP+ENERGY (endothermic)

7

(ATP-PC) For every molecule of PC that is broken down sufficient energy is released to resynthesise:

1 molecule of ATP

8

(ATP-PC) Benefits of ATP-PC system:

-Energy released rapidly
-Rapid resynthesis of ATP (necessary for short bursts of maximal work)
-No waste products
-Rapid resynthesis of PC stores

9

(ATP-PC) Disadvantages of ATP-PC system:

-Phosphocreatine stores are limited in muscle
-Only sufficient for 5-8s of high intensity/maximal work
-Take up to 3 min for PC stores to fully refuel
-Only 1 mole of ATP can be resynthesised through 1 mole of PC

10

Lactate anaerobic energy system involves the partial breakdown (glycolysis) of

glucose

11

(LACTATE/LACTIC ACID ENERGY SYSTEM) hydrogen ions are released during glycolysis, breakdown of glucose to pyruvate and complex chemical reactions occurring during the krebs cycle. These hydrogen ions are combined with oxygen in ETC to form water. This process works well for low-intensity exercise, but more ATP must be resynthesised as the level of work increases and therefore more glucose is broken down and more hydrogen is

transferred to the ETC

12

(LACTATE/LACTIC ACID ENERGY SYSTEM) More oxygen becomes available as the ventilation rate and cardiac output increase. The amount of oxygen that can be made available to and used by muscle cells is finite, and is known as the

VO2 max

13

(LACTATE/LACTIC ACID ENERGY SYSTEM) If body continues to work hard more hydrogen is released and at some point, so much hydrogen enters the ETC that it

exceeds the amount of oxygen available

14

(LACTATE/LACTIC ACID ENERGY SYSTEM) Excess hydrogen ions cannot remain unattached and so combine with the pyruvate to form lactate. The point at which this occurs is known as the

lactate threshold

15

(LACTATE/LACTIC ACID ENERGY SYSTEM) Benefits:

-ATP resynthesised quite quickly
-Presence of oxygen, lactic acid can be converted back into liver glycogen or used as a fuel through oxidation into CO2 and H2O
-Used to engage in maximal work

16

(LACTATE/LACTIC ACID ENERGY SYSTEM) Drawbacks:

-Produces lactic acid as a fatigue by-product
-Higher fatigue
-Too much lactic acid = acidic pH = enzymes can't work as well
-Muscle action = inhibited
-Oxygen debt