ATP Flashcards
What is an ATP molecule comprised of?
- Adenine
- Ribose
- Phosphates
What is adenine?
A nitrogen-containing organic base.
What is ribose?
A sugar molecule with a 5-carbon ring structure (pentose sugar) which acts as a backbone that the other parts are attached to.
How does ATP store energy?
The bonds between the phosphate groups are unstable and have low activation energy (easily broken).
They release lots of energy when broken.
What reaction converts ATP to ADP?
A hydrolysis reaction.
What enzyme catalyses the reaction that converts ATP to ADP?
ATP hydrolase.
Is the conversion of ATP a reversible reaction?
Yes
What kind of reaction reforms ATP from ADP?
A condensation reaction.
What enzyme catalyses the reaction that converts ADP to ATP?
ATP synthase.
Why isn’t ATP a good energy store?
Because of the instability of its phosphate bonds.
What makes ATP a good energy donor?
The instability of its phosphate bonds.
What kind of energy store is ATP?
An immediate energy source.
What does ATP stand for?
Adenosine Triphosphate.
How much ATP is typically stored in cells?
They maintain a few seconds supply which can easily be reformed from ADP produced.
Where is ATP made?
In the mitochondria of the cells that need it.
Why is ATP a better immediate energy source than glucose?
- ATP releases less energy than glucose but it is much more manageable than the greater release of energy by glucose.
- The hydrolysis of ATP is a single reaction whereas the breakdown of glucose requires multiple reactions so energy release takes longer.
Which processes require ATP
- Metabolic processes
- Movement
- Active transport
- Secretion
- Activation of molecules
Why is ATP required in metabolic processes?
It provides the energy required to build up macromolecules from their basic units.
eg: making starch from glucose
Why is ATP required in movement?
Provides the energy for muscle contraction - for the filaments of muscle to slide past one another and therefore shorten the overall length of the muscle fibre.
Why is ATP required for active transport?
Provides the energy to change the shape of carrier proteins in plasma membranes which allows molecules/ions to be moved against a concentration gradient.
Why is ATP required in secretion?
ATP is needed to form the lysosomes necessary for the secretion of cell products.
Why is ATP required in the activation of molecules?
The inorganic phosphate released during hydrolysis of ATP can be used to phosphorylate other compounds to make them more reactive (lowering the activation energy in enzyme-catalyses reactions)
Is ATP hydrolysis an endogenic or exogenic reaction?
Exogenic
