ATP Flashcards
what is energy required for in organisms?
in anabolic reactions- building larger molecules from smaller molecules
to move substances across the cell membrane (active transport) or to move substances within the cell
in animals:
for muscle contraction- to coordinate movement at the whole- organism level
in the conduction of nerve impulses, as well as many other celllular processes
what is the name of the molecule known as the universal energy currency?
ATP
Adenosine Triphosphate - a nucleotide
what type of nucleotide is ATP?
a phosphorylated nucleotide
phosphorylation involves the addition of phosphate to an organic compound
what is a nucleoside?
the combination of a nitrogenous base and a pentose sugar
the addition of a phosphate group to a nucleoside makes it a nucleotide
where is energy released during the reactions of respiration transferred to?
transferred to the molecule adenosine triphosphate (ATP)
Benefits of ATP
•The hydrolysis of ATP can be carried out quickly and easily wherever energy is required within the cell by the action of just one enzyme, ATPase
•A useful quantity of energy is released from the hydrolysis of one ATP molecule
- it reduces waste and gives the cell control over what processes occur
• Relatively stable at cellular pH levels
Hydrolysis of ATP
Hydrolysis of ATP to adenosine diphosphate (ADP) and an inorganic phosphate group (Pi) is catalysed by the enzyme ATP hydrolase (ATPase)
what can the hydrolysis of ATP be coupled to?
It can be coupled to energy- requiring reactions within the cells such as:
•the active transport of ions up a concentration gradient
•enzyme controlled reactions that require energy
•muscle contraction and muscle fibre movement
What happens when ADP forms free energy?
It can be hard for processes with a cell
e.g. DNA synthesis
-removal of one phosphate group from ATP releases 30.8kJ/mol of energy,
forming ADP
- removal of a second phosphate group from ADP also releases 30.8kJ/mol of energy, forming AMP
- removal of the third and final phosphate group from AMP releases 14.2kJ/mol of energy, forming adenosine
the inorganic phosphate released during the hydrolysis of ATP can be used to phosphorylase other compounds, often making them more reactive
when is ATP formed?
when ADP is combined with an inorganic phosphate (Pi) group by the enzyme ATP synthase
- this is an energy requiring reaction
- water is released as a waste product
( therefore ATP synthesis is a condensation reaction)
Types of ATP
ATP is made during the reactions of respiration and photosynthesis
- all of an animals ATP comes from respiration
ATP can be made in two different ways:
- substrate- linked phosphorylation
(occurs in the glycolysis stage of respiration)
- chemiosmosis (occurs in the electron transport chain stage of respiration)
