Energy and ATP Flashcards
1
Q
What is ATP and what is it made of?
A
Its a phosphorylated molecule made of three parts:
- Adenine, a nitrogen containing base
- Ribose, a sugar molecule with a 5 carbon ring structure, it acts as a backbone to which the other molecules are attached
- Phosphates, a chain of three phosphate groups
2
Q
How does ATP store energy?
A
- the bonds between the phosphate groups are unstable and so have low activation energy
- so release large amounts of energy when they break
3
Q
How does ATP release energy?
A
In a hydrolysis reaction which is catalysed by ATP hydrase
4
Q
What is the general formula of energy release?
A
ATP+(H2O) makes ADP+Pi+E where Pi is a phosphate group and E in energy
5
Q
How is ATP synthesised?
A
- the conversion of ATP to ADP is reversible
- energy can be used to add an inorganic phosphate to ADP to re- form ATP
- This is catalysed by ATP synthase in a condensation reaction
- this can happen in three ways
6
Q
In which three ways is ATP synthesised?
A
- In chlorophyll containing plant cells during photosynthesis ( photo phosphorylation )
- In plant and animal cells during respiration ( oxidative phosphorylation )
- In plant and animal cells when phosphate groups are transferred from donor molecules to ADP ( substrate level phosphorylation )
7
Q
What are the roles of ATP?
A
- energy is released in small manageable quantities
- hydrolysis of ATP to ADP is a single reaction that releases energy immediately
- ATP cannot be stored and is therefore continuously made in the mitochondria of the cells where it is needed
8
Q
What processes require ATP?
A
- Metabolic processes - to build up macromolecules eg starch from glucose or polypeptides from amino acids
- Movement - muscle contraction
- Active transport - ATP provides energy to change the shape of carrier proteins in the plasma membrane
- secretion - ATP is needed to form lysosomes necessary fro secretion
- Activation of molecules - making compounds more reactive eg to phosphate glucose at the start of glycolysis
