ATP, Water and inorganic ions Flashcards
What is the main energy source to carry out processes within cells
Adenosine Triphosphate (ATP)
What type of molecule is an ATP molecule
A phosphorylated macromolecule
What is the structure of ATP
Adenine - A nitrogen - containing organic base, Ribose - (pentose sugar) acts as backbone and phosphates - a chain of three phosphate groups
How does ATP store and release energy
ATP consists of 3 phosphate groups. The bonds between these phosphate groups are unstable and so have low activation energy, which means that they are easily broken. When they break they release a considerable amount of energy.
Which phosphate is usually removed in living cells
The terminal phosphate
What is the equation for the hydrolysis of ATP
ATP + (H2O) -> ADP (Adenosine diphosphate) + Pi (inorganic phosphate) + E (Free Energy)
What type of reaction is the conversion of ATP to ADP
Hydrolysis Reaction
What enzyme is catalyses the conversion of ATP to ADP
ATP hydrolase (ATPase)
Is the conversion of ATP to ADP reversible?
Yes
How can ADP be converted to ATP
Energy can be used to add an inorganic phosphate to ADP to re-form ATP.
What enzyme is catalyses the conversion of ADP to ATP
ATP Synthase
What type of reaction is the conversion of ADP to ATP
Condensation Reaction
How does the synthesis of ATP from ADP occur
The addiction of a phosphate molecule to ADP.
What are the three ways the addiction of a phosphate molecule to ADP occurs
In chlorophyll containing plant cells during photosynthesis (photophosphorylation), In plant and animal cells during respiration (oxidative phosphorylation), In plant and animal cells when phosphate groups are transferred from donor molecules to ADP (substrate level phosphorylation)
Why is ATP not a good long term energy store
The instability of ATP’s bonds, mean it is a better immediate energy source of a cell.
How do cells store ATP
Cells do not store large quantities of ATP, but rather just maintain a few seconds of supply. This is not a problem as ATP is rapidly reformed from ADP and Pi.
Why is ATP a better immediate energy source than glucose
Each ATP molecule releases less energy than each glucose molecule. The energy for reactions is therefore released in smaller, more manageable quantities rather than the much greater, and therefore less manageable release of energy from Glucose.
The breakdown of glucose is a long series of reactions and therefore the energy release takes longer than the single reaction which is the hydrolysis of ATP to ADP, releasing immediate energy.
What has to happen for ATP to be sustained
ATP cannot be stored and so has to be made continuously within the mitochondria of cells that need it.
How is ATP used in metabolic processes
ATP provides the energy needed to build up macromolecules from their basic units. E.g. Starch from Glucose
How is ATP used in movement
ATP provides the energy for muscle contraction. In muscle contraction, ATP provides the energy for the filaments of muscle to slide past one another and therefore shorten the overall length of a muscle fibre.
How is ATP used in active transport
ATP provides the energy to change the shape of carrier proteins in plasma membranes. This allows molecules or ions to be moved against a concentration gradient.