3.11 - ATP Flashcards
What are the 3 main types of activity that cells require energy for?
- Synthesis - of large molecules e.g. proteins
- Transport - e.g. pumping molecules by active transport
- Movement - muscle contraction (protein fibres)
What is the structure of an ATP molecule?
- ATP and ADP are phosphorylated nucleotides
- Nitrogenous base - always adenine
- Pentose sugar is ribose
- 3 inorganic phosphate groups PO42- (ADP has 2 phosphate groups)
Why is ATP known as universal energy currency?
ATP is used for all energy transfer in living cells
Is energy taken in or released for: Bond making?; Bond breaking?
Bond making - energy is released Bond breaking - energy is taken in
How does ATP release energy?
- It is a hydrolysis reaction
- Small amount of energy needed to break last of the 3 phosphate groups off
- Once the phosphate is released and involved in other bond formation reactions - lots of energy is released
- ATP + water > ADP + Pi + energy
- ATP hydrolysis is coupled with energy requiring reactions
How is ATP reformed?
It is the reverse reaction of ATP releasing energy
Which is a condensation reaction
The energy required to reform ATP comes from cellular respiration
Reattachment of Pi to ADP known as phosphorylation
Why is ATP not good for long term energy storage?
Phosphate bonds are unstable - fats and carbs are better ATP is a good immediate energy store as the ATP <> ADP + Pi is constantly occuring.
What are the properties of ATP?
- Energy released in small quantities
- They are small, can move easily into and out of cells
- Bonds between phosphate have enough energy for cellular reactions (not too much waste energy)
- Easily regenerated
- Water soluble - good for energy requiring processes in aq conditions
