3.11 - ATP Flashcards
Name 4 biological processes that require energy
- muscle contraction
- cell division
- transmission of nerve impulses
- memory formation
Name three main types of activities cells need energy for AND name an example for each
- synthesis - protein synthesis
- transport - pumping ions/ molecules across cell membranes
- moving vesicles through cytoskeleton - movement - e.g. protein fibres in muscle cells for muscle contraction
State the structure of ATP
- 3 phosphate groups
- a pentose sugar
- adenine (nitrogenous base)
Why is it called universal energy currency?
It is used for energy transfer in all cells of all living things
What type of reaction occurs when ATP breaks down
Hydrolysis reaction
What does ATP break down into?
Adenosine diphosphate(ADP) and an inorganic phosphate ion (Pi)
State the word equation for break down of ATP
ATP + water —> ADP + inorganic phosphate ion (Pi) + energy
How much energy is approximately released when the free phosphate iron undergoes other reactions involving bond formations?
Approx 30.6kJmol-1
Which need more energy? Energy required to break bond between last and second last phosphate groups or the energy released when free phosphate ion undergoes bond forming reactions.
Small amount of energy needed to break bond between last and second last phosphate groups. A lot more energy is released when free phosphate ion undergoes bond forming reactions
What does ‘reactions are ‘coupled’’ mean?
Hydrolysis of ATP occurs in association with energy-requiring reactions - both reactions occur simultaneously
Why is ATP not a good long-term energy store?
The bonds between the phosphate groups are unstable
What energy source or material is broken down to create ATP?
Fats and carbohydrates are broken down through cellular respiration to release energy that is used to make ATP
What is the type of reaction for when ATP is reformed?
Condensation
What is the name of the reaction in which ATP is reformed?
Phosphorylation of ADP
Describe the phosphorylation of ADP
Phosphate ion re-attaches itself to ADP
Why don’t cells have a large store of ATP?
The rapid interconversion of ATP and ADP happens constantly in all living cells so cells do not need a large store of it - hence ATP is a good immediate energy store
Name 5 properties of ATP
- small - moves easily into, out of and within cells
- water soluble - energy-requiring processes can occur in aqueous environments
- releases energy in small quantities - suitable to most cellular needs - energy not wasted as heat
- easily regenerated - can be recharged with energy
- contains bonds between phosphates with intermediate energy - energy is large enough for cellular reaction but not enough to be wasted as heat
