Biochemistry Part 2

Neutralization

• An acid is a substance that produces hydrogen ions (H+) when it is dissolved in water.

• A base is a substance that produces hydroxide ions (OH-) when it is dissolved in water.

• A pH scale ranks the substances according to the relative concentrations of their hydrogen ions. Substances with pH of less than 7 are considered acids, and higher than 7 are considered bases.

• When acids and bases mix, they undergo a neutralization reaction that results in the formation of salt and water

• Normal human blood pH is 7.35-7.45.• Alkalosis is when a person’s pH levels go up (high

altitudes, anxious)• Acidosis is when the blood pH lowers to 7.1-7.3 and

can cause fatigue. Above 7.8 and below 6.8 can be fatal

• We need buffers that will maintain pH balance• A buffer system we have in our blood is the carbonic

acid and hydrogen carbonate ion.• http://www.youtube.com/watch?v=l9dliAngF2k

Oxidation-Reduction Reactions

• LEO says GER• Loss of elections: oxidation• Gain of elections: reduction• C6H12O6 + 6O2 -> 6CO2 + 6H2O

Sugar is oxidized in a series of reactions to get energy.

Condensation Reactions• When you react two separate molecules to

join and a water molecule is released. Also called a dehydration reaction.

Hydrolysis Reaction

• When you breakdown macromolecules into its monomers using a water molecule.

Condensation and Hydrolysis

Enzymes

• A certain amount of energy is required to start any reaction. This is called the activation energy.

• There are several ways to lower the activation energy or speed up a reaction: increase temperature (not recommended in living things) or use a catalyst.

• A protein molecule can make biological catalysts called enzymes.

• Every different reaction that occurs in our body has a certain enzyme that will facilitate the reaction.

• Enzymes have specific 3D shapes with indentations on their surfaces called the active site where the substrate (reactants of the reaction) will bind.

• When the substrate and enzyme are bound together, it is called the enzyme-substrate complex

• The enzyme will then adjust its shape, allowing the reaction to happen easier

• Some enzymes need the help of other organic molecules… called coenzymes

• Some enzymes may need the presence of ions such as iron or zinc… called cofactors

• Enzymes are classified based on the type of reaction they catalyze. For example, enzymes that catalyze hydrolysis reactions are called hydrolases.

• Enzymes are specific – i.e. lactase

• Enzyme activity can be affected by a change in condition that alters the enzyme’s shape (temperature and pH)

• Inhibitors are molecules that interact with an enzyme and reduce the activity of the enzyme and its ability to bind with a substrate– Competitive inhibition: inhibitors that interact with the

active site– Non-competitive inhibitors: bind to an allosteric site (not

the active site, but changes the shape of the active site)• Activators: molecules that can also bind to an

allosteric site, but change the shape of the active site to make it so the substrate CAN bind to the enzyme.