A.2.3.1 (2) Aerobic and Anaerobic energy systems

anaerobic energy systems

• ATP-PC (Phosphocreatine) System

• Lactic acid system

what are some key characteristics of the ATP-PC system

• duration: ~10 seconds

• site of reaction: cytoplasm

• fuel source: phosphocreatine, stored in the sarcoplasm

• Oxygen use: none

• bi-products: only heat

what type of activites use the ATP-PC system

very high (maximum) intensity activities

1 - what happens to ATP in the ATP-PC system

ATP is broken down into ADP by the enzyme ATPase and Pi to release energy for muscle contraction

2 - what happens to phosphocreatine in the ATP-PC system

broken down by creatine kinase to release energy to rebuild ATP

2 (i) - what is phosphocreartine broken down into

creatine and energy

3 - what does this result in the ATP-PC system

the energy in the break down of PC is used to resynthesises ATP from ADP

what are some sporting examples for the ATP-PC system

sprint races, weightlifting, high jump, shot put, and short distance swimming events.

lactic acid system or…

anaerobic glycolysis

1 - what happens first in the lactic acid system

glycogenolysis occurs, breaking down glycogen into glucose in the sarcoplasm

2 - what happens after the glycogenolysis

glycolysis, glucose is broken down into pyruvate

2 (i) - what enzyme breaks down the glucse to pyruvate

phosphofructinase (PFK)

2 (ii) - what is produced as a result of this glycolysis

2 ATP molecules

3 - what happens to the pyruvate

due to no oxygen, it will not enter the aerobic system so is converted into lactic acid (lactate)

4 - how long does the energy last for the lactic acid system

10 seconds to 3 minutes

what type of activities/sporting examples use the lactic acid system

high intensity activities, e.g 400m sprints, long jump

how many stages are in the aerobic energy systems

three

1 - what does it share similarly with the lactic acid system

glycoloysis [aerobic], glucose is broken down into pyruvate/pyruvic acid = 2 ATP

1 (i) - what enzyme is used to do this

PFK

2 - Krebs cycle

pyruvate is broken down into acetyl-CoA in the mitochondria

2 (i) - Krebs cycle

acetyl-CoA is broken down further to produce 2 ATP, CO₂ and hydrogen

2 (ii) - Krebs Cycle, what do the hydrogen ions do

carry electrons and are liberated from the hydrogen ions and passed through the electron transport chain

3 - what does the electron transport chain do

uses the hydrogen ions to generate ATP, with oxygen helping to form water

3 (ii) - how many ATP molecules are produced and how long does it last

34 ATP, lasting 2+ minutes (up to hours)