The flow of energy 5
Each ATP molecule has three parts
1. sugar. 2. an adenine nucleotide. 3. A chain of three phosphate groups.
Activation energy
All chemical reactions require an initial input of energy called activation energy.
Allosteric enzymes
Are affected by the binding of signal molecules. Some signals act as repressors
Enzymes
Are the catalysis used by cells to perform particular reactions. Enzymes bind specially to a molecule and stress the bonds to make the reaction more likely to proceed.
Cellular respiration
Cells break down the potential energy in sugars and convert it ATP.
Activators
Change the shape of the enzyme so that it can bind substrate.
Fist law of thermodynamics
Concerns the amount of energy in the universe.
Second law of thermodynamics
Concerns this transformation of potential energy into heat, or random molecular motion.
There are two kinds of chemical reactions
Endergonic reactions and exergonic reactions.
Exergonic reactions
Have products with less energy that the reactants. These reactions tend to occur spontaneously.
Reactants
In a chemical reaction, the original molecules before the chemical reaction occurs are called reactants, or sometimes substrates.
Repressors
Inhibit the enzyme when bound.
Feed back inhibition
Is a form of a enzyme inhibition where the product of a reaction acts as repressor.
Energy
Is defined as the ability to do work.
Second law of thermodynamics
Is states that the disorder in a closed system like universe it continuously increasing.
Adenosine triphosphate (ATP)
Is the energy currency of the cell
Kinetic energy
Is the energy of motion.
Chemical reaction
Is the making or breaking of chemical bonds.
Entropy
Is the measure of the degree of disorder system, so the second law of thermodynamics can also be stated simply as "entropy increases."
Active site
Is the site on the enzyme that binds to a reactant.
Energy
It can be considered to exit in two states: kinetic energy and potential energy.
First law of thermodynamics
It states that energy can change from one state to another ( from potential to kinetic, for example) but it can never be destroyed, nor can new energy be made.
Potential energy
Objects that are not in the process of moving but have the capacity to move are said to possess potential energy, or stored energy.
Photosynthesis
Some cells convert energy from the sun into ATP and then use it to make sugars that store potential energy.
Activation energy
The activation energy initiates a chemical reaction by destabilizing existing chemical bonds.
Competitive inhibition
The inhibitor competes with the substrate for the active site The inhibitor can block the active site to that it cannot bind the substrate.
Catalysis
The process of lowering the activation energy of a reaction is called catalysis.
Biochemical pathway
The product of one reaction is the substrate for the next reaction until a final product is made. The series of reactions is called a biochemical pathway.
Binding site
The site on the reactant where the enzyme binds is called the binding site.
Coupled reactions
Usually endergonic reactions are coupled with the breakdown of ATP
Products
Whereas the molecules that result after the reaction has taken place are called the products.
Endergonic reactions
have products with more energy than the reactants. These reactions require an input of energy.