3: ATP Flashcards
What do cells require energy for?
Synthesis, transport, movement
What is ATP?
Adenosine triphosphate
What is an ATP molecule composed of?
Nitrogenous base (adenine), pentose sugar, three phosphate groups
Why is ATP known as the universal energy currency?
It transfers energy in all cells of all living things
How does ATP release energy?
Energy is released when bonds are formed. A small amount of energy is needed to break the relatively weak bond holding one phosphate group in ATP and then a large amount of energy is released when the free phosphate undergoes other reactions involving bond formation. Energy released = 30.6kJmol-1
What is the equation for the hydrolysis of ATP (the reaction that release/provides energy)?
ATP + H2O –> ADP + Pi (inorganic phosphate) + energy
ATP is hydrolysed into adenosine diphosphate and a phosphate ion, releasing energy
Why is ATP not a good long-term energy store?
The instability of the phosphate bonds in ATP
What are better long-term energy store?
Fats and carbohydrates
What is phosphorylation?
Reattaching a phosphate group to an ADP molecule. Occurs when fats and carbohydrates are broken down to release energy to create ATP
Why don’t cells store large amounts of ATP?
Due to ATPs instability
Why do cells not need a large store of ATP?
ATP is rapidly reformed by phosphorylation of ADP and this interconversion is happening constantly
What are the properties of ATP?
- Small: moves easily into, out and within cells
- Water soluble: energy-requiring processes happen in aqueous environments
- Releases energy in small quantities
- Easily regenerated
