Structure and Function of ATP Flashcards
ATP is short for
Adenosine Triphosphate
It is often referred to as the energy currency of a cell as it can pick up energy and transfer that energy to another chemical process.
ATP
Contains sugar ribose, N-base adenine, and a chain of three phosphate group
ATP
Responsible for mediating most energy coupling in cells, and in most cases, it acts as the immediate source of energy that powers cellular work.
ATP
One of the nucleoside triphosphates used to make RNA
ATP
3 main kinds of work of a cell
chemical work, transport work, and mechanical work
works of the cell are possible through
energy coupling
cells use an exergonic process to drive an endergonic reaction.
energy coupling
synthesis of polymers from monomers (pushing of endergonic reactions)
chemical work
pumping of substances across membranes (against the direction of spontaneous movement)
transport work
beating of cilia, contraction of muscles
mechanical work
also used to make RNA
ATP
phosphate groups are bonded by
phosphoanhydride bonds
ribose and triphosphate group are bonded by
phosphoester bonds
The bond between phosphate groups can be broken down by
hydrolysis
When the terminal phosphate is broken down by the addition of a water molecule, a molecule of _____ leaves the ATP.
inorganic phosphate (HOPO3
-2)
ATP is (type of reaction) and releases ____ kcal of energy per mole of ATP hydrolyzed.
exergonic
-7.3kcal
process of hydrolysis
- A lone pair of e- of oxygen in H2O will launch a nucleophilic attack on the phosphorus (of phosphate).
- However, it needs to overcome the negative charges to get close to the POSITIVE CHARGES. It can be done with the help of ATPases.
- ATPases surround the ATP molecule with positive ions and keep the negative ions busy.
- Eventually the electrons can bond with terminal P and cleave the bond.
- At the end of hydrolysis, ADP and inorganic phosphate (HOPO3
-2) are formed.
addition of water
hydrolysis
enzyme that helps in hydrolysis
ATPase
why does this hydrolysis release so much energy?
electrostatic repulsion
the adjacent negative charges
repel each other
electrostatic repulsion
when an animal is exposed to a cold environment, the reaction of the body is through
shivering
shivering uses ATP during ______ to warm the body.
muscle contraction
the energy released during ATP hydrolysis is used by ___ to perform work
proteins
it leads to a change in the shape of the protein and in its ability to bind to another molecule.
hydrolysis of ATP
ADP to ATP
phosphorylation
ATP to ADP
dephosphorylation
promote crucial protein shape changes during important cellular process
phosphorylation and dephosphorylation
the use of an exergonic process to drive an endergonic one
Reaction Coupling
Two reactions are linked together with one providing the energy needed for the other to occur.
Reaction Coupling
The linking often happens through a shared intermediate, meaning that a product of one reaction is “picked up” and used as a reactant in the second reaction.
Reaction Coupling
The energy generated from one reaction is used to drive the second reaction. This is being done by phosphorylation.
Reaction Coupling
The energy generated from one reaction is used to drive the second reaction. This is being done by
phosphorylation
a product of one reaction is “picked up” and used as a reactant in the second reaction
shared intermediate
ATP binds to motor proteins and then is hydrolyzed, causing a shape change that walks the motor protein forward
mechanical work
ATP phosphorylates transport proteins, causing a shape change that allows transport of solutes
transport work
ATP hydrolysis is
reversible
The _____ is just the reverse of the hydrolysis reaction:
ATP regeneration reaction
ATP regeneration reaction
energy+ADP+Pi⇋ATP+H2O
