1.1 Energy For Exercise Flashcards
What happens when ATP is broken down?
Energy is released
What enzyme breaks down ATP?
ATPase - stimulates a high energy bond to be broken
What is an endothermic reaction?
A chemical reaction which absorbs energy
What is an exothermic reaction?
A reaction which releases energy
What is the ATP-PC system used for? How long is it used for?
High intensity activity
2-10 seconds of exercise
What enzyme breaks down phosphocreatine?
Creatine kinase
Where is PC broken down?
The sarcoplasm
What is the ratio of PC: ATP
1:1
What is a coupled reaction?
Where the products of one reaction are used in another reaction
What is the glycolytic system used for? How long does it last?
High intensity activity
10 seconds to 3 minutes of exercise
What enzyme breaks down glucose?
Phosphofructokinase (PFK)
What enzyme is released if glucose levels drop? What does it do?
GPP - glycogen phosphorylase
Catalyses the breakdown of stored glycogen, allows glucose concentration in bloodstream to be maintained
What is anaerobic glycolysis? What does this result in?
Breakdown of glucose in the absence of oxygen
Pyruvate
Give examples of sports that can occur during the glycolytic system phase
200-400m track
100m freestyle
Counter attack in football
Distancing from the pack in a marathon
How long does the glycolytic system last?
Up to 3 minutes
What enzyme catalyses the conversion of pyruvic acid into lactic acid?
LDH - lactate dehydrogenase
What are the 3 aerobic systems?
Aerobic glycolysis
Krebs cycle
Electron transport chain
Briefly describe what happens in the aerobic glycolysis stage (5)
PFK converts the glucose into pyruvic acid, releasing energy to synthesis 2 ATP molcules
GPP converts glycogen into glucose for extended periods of time
Oxygen is now in sufficient supply, pyruvic acid isn’t converted into lactic acid
It goes through the link reaction catalysed by co enzyme A, producing acetyl CoA
This allows access to mitochondria
Briefly describe the Krebs cycle
Acetyl CoA combines with oxaloacetic acid to make citric acid
Where does the Krebs cycle occur?
Matrix of the mitochondria
What is the stored ATP reaction? How long does it last?
Store of ATP where muscle is quickly exhausted:
Quick powerful contractions
2-3 seconds
Briefly describe the electron transport chain. (3)
Hydrogen atoms are carried through the ETC along cristae by NAD and FAD, splitting into electrons and H+
Hydrogen is oxidised and removed as water
Pairs of electrons carried by NAD release enough energy to resynthesise 30 moles of ATP and FAD release enough energy to resynthesise 4 moles of ATP
How long does it take for PC stores to be 50% and 100% replenished?
50% - 30 seconds
100% - 3 minutes
