ATP Flashcards
What’s ATP stands for
Adenosine Triphosphate
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
ATP Contains ?
sugar ribose
N-base adenine
chain of three phosphate group
Responsible for mediating most energy coupling in cells
ATP
it acts as the immediate source of energy that powers cellular work.
ATP
One of the _______ used to make RNA
nucleoside triphosphates
3 kinds of work of a cell
chemical work, transport work, and mechanical work
These are possible through energy coupling, where the cells use an exergonic process to drive an endergonic reaction.
chemical work, transport work, and mechanical work
synthesis of polymers from monomers (pushing of endergonic reactions)
Chemical work
ATP phosphorylates key reactants, providing energy to drive energy absorbing chemical reactions
Chemical Work
ATP phosphorylates transport proteins, activating them to transport solutes (ions) across cell membranes
Transport Work
ATP phosphorylates contractile proteins in muscle cells so the cells can shorten
Mechanical Work
pumping of substances across membranes (against the direction of spontaneous movement)
Transport work
beating of cilia, contraction of muscles
Mechanical work
The bond between phosphate groups can be broken down by _____.
Hydrolysis
When the________ is broken down by the addition of a water molecule, a molecule of
inorganic phosphate (HOPO3-2) leaves the ATP.
terminal phosphate
What happens during ATP 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.
The energy released by ATP on losing a phosphate group is somewhat _____ than the energy most other molecules could deliver.
greater
But why does this hydrolysis release so much energy?
If we reexamine the ATP molecule in Figure 8.9a, we can see that all three phosphate groups are negatively charged. These like charges are crowded together, and their mutual repulsion contributes to the instability of this region of the ATP molecule. The triphosphate tail of ATP is the chemical equivalent of a compressed spring.
Electrostatic Repulsion
The adjacent negative charges repel each other. The molecule can achieve a lower energy state by hydrolysis, which allows the phosphate groups to separate from each other.
Will it be a disadvantage for organisms to generate heat during ATP hydrolysis
Yes
To maintain the living conditions inside the cell, the energy released during ATP hydrolysis is used by____ to perform work: chemical, transport, and mechanical
proteins
_____ of ATP leads to a change in the shape of the protein and in its ability to bind to another molecule.
Hydrolysis
_____ (ADP to ATP) and ______ (ATP to ADP) promote crucial protein shape changes during important cellular process
Phosphorylation, 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 ______, meaning that a product of one reaction is “picked up” and used as a reactant in the second reaction.
shared intermediate
The energy generated from one reaction is used to drive the second reaction. This is being done by?
phosphorylation
ATP hydrolysis releases ____ kJ/mol
-30.5
To synthesize sucrose from glucose and fructose,_____ kJ/mol* is required.
+ 27
