Energy and ATP Flashcards
What are the 3 parts of an ATP?
- Adenine - A nitrogen-containing organic base.
- Ribose - A pentose sugar.
- Phosphate - A chain of 3 phosphate groups.
Draw the structure of ATP.
Draw on a piece of paper.
How does ATP store energy?
The bonds between the 3 phosphate groups are unstable so it has a low activation energy meaning that it can be easily broken. When they do break, it can release a lot of energy.
Write the equation that expresses the break down of ATP.
ATP + H2O —-) ADP + Pi + E
(Adenosine ( Inorganic (Energy)
diphosphate) phosphate)
What is the process when ATP is converted into ADP?
Hydrolysis reaction and this reaction is catalysed by enzyme ATPase ( ATP hydrolase).
What are the features of ATP that make it suitable for the immediate release of energy?
1) Easily hydrolysed (broken off)
2) It only requires one step of hydrolysis reaction to being broken down into useable energy.
3) Highly soluble.
How can ADP convert back into ATP?
Inorganic phosphate can be added to ADP and be catalysed by enzyme ATP synthase, it can reform ATP.
As water is removed from this, this is a condensation reaction.
Describe 3 ways which ATP can be resynthesized.
1) In chlorophyll-containing plant cells during photosynthesis (photophosphorylation).
2) In plants and animals during respiration (oxidative phosphorylation).
3) In plant and animal cells when phosphate groups are transferred from donor molecules to ADP (substrate level phosphorylation).
Why do cells not store a large amount of ATP?
Because of its instability phosphate bonds, it’s not good for long term storage, therefore, it’s the immediate energy source of a cell so cells do not store them, but just maintain a few seconds’ supplies. But it’s not a problem because ATP can be rapidly reformed from ADP and Pi so little is lost during the process.
Why is ATP a better immediate source of energy than glucose?
- Each ATP molecule releases less energy than each glucose molecule, therefore, the energy that has been released is in smaller and more manageable quantities rather than the large supplies from glucose.
- The hydrolysis of ATP to ADP is a single reaction whereas the breakdown of glucose is a long series of reactions, therefore, it takes longer and ATP would provide a faster immediate source of energy.
Why do cells need mitochondria?
Because ATP cannot be stored, therefore it has to be constantly made to provide enough energy for the cells to do its job, especially cells such as muscle fibers and epithelium of the small intestine which require energy for movement and active transport.
How can ATP be used in metabolic processes?
Metabolic processes - ATP provides energy for the build-up of macromolecules from their basic units e.g. making starch from glucose or polypeptides from amino acids.
Example of where it can take place: Mesophyll cell.
How can ATP be used in movements?
Movements - ATP provides energy for muscle contraction. In muscle contraction, ATP provides the energy for the filaments of muscle to slide past one another to shorten the overall length of a muscle fiber.
Example of where it can take place: Mammal’s skeletal muscle cells.
How can ATP be used in active transport?
Active transport - ATP provides the energy to change the shape of carrier proteins in the plasma membrane which allows molecules or ions to be moved against the concentration gradient.
Example of where it can take place: Plant root hair cells.
How can ATP be used in secretion?
Secretion - ATP is needed to form the lysosomes that are necessary for the secretion of cell products.
Example of where it can take place: Small intestine epithelial cells.
