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 Alkalosis is when a person’s pH levels go up (high altitudes, anxious) Acidosis is when the blood pH lowers to 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.

Oxidation-Reduction Reactions LEO says GER Loss of elections: oxidation Gain of elections: reduction C 6 H 12 O 6 + 6O 2 -> 6CO 2 + 6H 2 O 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.