2.3 Energy and ATP Flashcards
What is ATP
Adenosine Triphosphate is a nucelotide derivative and is an immediate source of energy
Describe the sturcture of ATP
A ribose bound to a molecule of Adenine-nitrogenous base- and 3 Phosphate groups
Nucleotide derivative
Describe how ATP is broken down
ATP + water —> ADP(Adenosine diphosphate) + Pi (inorganic Phosphate)
Hydrolysis reaction using a water molecule
Catalysed by ATP hydrolase
Give two ways in which the hydrolysis of ATP is used in cells
- Coupled to energy requiring reactions within cells which releases energy for Active transport or protein synthesis
- Inorganic phosphate released can be used to phosphorylate ( add phosphat to) other compounds making them more reactive
Descrine how ATP is resynthesised in cells
ADP +Pi—> ATP (water)
Condensation reaction removing a water molecule
Catalysed by ATP synthase (enzyme)
During respiration and photosynthesis
Suggest how the properties of ATP make it a suitable immediate source of energy for cells
Releases energy in small amounts
Single reactions hydrolysed to release energy ( so immediate release)
Cannot pass out of cell
How is ATP an immediate source of energy
When you break one of the bonds between the phosphate groups a small amount of energy is released to the surroundings
What is phosphorylation
When an inorganic phosphate is released during the hydrolysis of ATP
It can be bonded on to different compounds to make them more reactive
Give an example of phosphorylation
In the first stage of respiration glucose gets phosphorylysed to make it more reactive
What are the 5 properties of ATP
- ATP releases a small amount of energy—> no energy is wasted
- ATP is a small and soluble molecule—> can be easily transported around the cell
- Only one bond needs to be hydrolysed in order to release energy which is why energy release is immediate
- Can transfer energy to another molecule by transferring one of its phosphate groups through phosphorylation making other compounds more reactive
- ATP cannot pass out of the cell—> cannot diffuse through the cell surface membrane and there are no protein carries that it can attach to so every cell has its own supply of ATP
What is a benefit of no energy being wasted through the use of ATP
Cells do not over heat from wasted heat energy and cells are less likely to run out of resources
WHY IS ENERGY IMPORTANT?
Plants and animals need energy for biological processes to occur:
Active transport
DNA replication
Cell division
Protein synthesis
Building larger molecules from smaller
ATP AND RESPIRATION
Adenosine triphosphate is a nucleotide derivative. Modified form of a nucleotide.
It is not energy it is a store of energy .
Energy is used to make ATP.
Energy is released when ATP is hydrolysed
Made from an adenine nucleotide base, ribose pentose sugar and 3 phosphate groups.
Respiration is the release of energy from glucose.
The energy released from glucose is used to make ATP.
Once ATP is made, it diffuses to part of the cell that requires energy.
WHY DO WE NEED ATP IF WE HAVE GLUCOSE?
A cell cannot get its energy directly from glucose so it is broken down in respiration in order for energy to be released.
This is because glucose is:
Glucose is a bigger molecule and is not as easy to transfer.
Not as easily broken down, it is a multistage process.
BREAKING ATP
When a cell needs energy ATP is broken down during a hydrolysis reaction which requires a water molecule into ADP (adenosine diphosphate)and Pi (inorganic phosphate). When the phosphate bond is broken, energy is released. The reaction is catalysed by ATP hydrolase.
RESYNTHESIS OF ATP
ATP can be re-synthesised in a condensation reaction between ADP and Pi . A water molecule is lost when a new phosphate bond is formed. This happens during both respiration and photosynthesis, and is
catalysed by the enzyme ATP synthase.
