Ch 2: Chemistry of Life pt. 2
Chemical reactions: reactions that change substances into substances by breaking and forming chemical bonds.
Reactants: The substances that changed during a chemical reaction.
Products: The substances made by a chemical reaction.
Chemical equations show what happens during a reaction. The left has the reactants and the right has the products. The arrow shows the direction of the equation.
Bond energy: the amount of energy that will break a bond between two atoms.
Bonds between different atoms have different bond energies.
The energy released when a bond forms is the amount of energy that will break the bond.
Chemical equilibrium: When a reaction takes place at an equal rate in both directions. (reversible chemical reactions).
Equilibrium is reached when both the reactants and products are made at the same rate.
All chemical reactions have changes in energy.
If energy is added to reactants, chemical bonds are broken.
Energy is released when new bonds form in the products.
Activation energy: the amount of energy that needs to be absorbed for a chemical reaction to start.
Activation energy is absorbed by reactants.
Exothermic chemical reaction: Reaction that releases more energy than it absorbs.
Energy that is released is given off as heat or light.
Think exo → out
Endothermic chemical reaction: Reaction that absorbs more energy than it releases.
Energy that is absorbed can come from energy sources like the sun.
Think endo → in
Catalyst: a substance that decreases the activation energy needed to start a chemical reaction.
A catalyst will increase the speed of a chemical reaction as it gives it a “push”.
Chemical reactions in organisms usually need catalysts.
Enzymes: catalysts for chemical reactions in living things
Lower the activation energy and speed up chemical reaction.
Needed in most processes of organisms.
Most enzymes are proteins.
Changes in temperature or pH can change an enzyme’s structure and affect how an enzyme functions.
Substrates: The only reactants that a certain enzyme will act on.
Enzymes will bring the substrates together and act as a catalyst so the product can be formed easier.
Chemical reactions: reactions that change substances into substances by breaking and forming chemical bonds.
Reactants: The substances that changed during a chemical reaction.
Products: The substances made by a chemical reaction.
Chemical equations show what happens during a reaction. The left has the reactants and the right has the products. The arrow shows the direction of the equation.
Bond energy: the amount of energy that will break a bond between two atoms.
Bonds between different atoms have different bond energies.
The energy released when a bond forms is the amount of energy that will break the bond.
Chemical equilibrium: When a reaction takes place at an equal rate in both directions. (reversible chemical reactions).
Equilibrium is reached when both the reactants and products are made at the same rate.
All chemical reactions have changes in energy.
If energy is added to reactants, chemical bonds are broken.
Energy is released when new bonds form in the products.
Activation energy: the amount of energy that needs to be absorbed for a chemical reaction to start.
Activation energy is absorbed by reactants.
Exothermic chemical reaction: Reaction that releases more energy than it absorbs.
Energy that is released is given off as heat or light.
Think exo → out
Endothermic chemical reaction: Reaction that absorbs more energy than it releases.
Energy that is absorbed can come from energy sources like the sun.
Think endo → in
Catalyst: a substance that decreases the activation energy needed to start a chemical reaction.
A catalyst will increase the speed of a chemical reaction as it gives it a “push”.
Chemical reactions in organisms usually need catalysts.
Enzymes: catalysts for chemical reactions in living things
Lower the activation energy and speed up chemical reaction.
Needed in most processes of organisms.
Most enzymes are proteins.
Changes in temperature or pH can change an enzyme’s structure and affect how an enzyme functions.
Substrates: The only reactants that a certain enzyme will act on.
Enzymes will bring the substrates together and act as a catalyst so the product can be formed easier.
