Chapter 3: Chemistry of Life Enzymes

Carbon and Bonding What makes carbon so unique is the ability to bond 4 times because it has 4 valence shell electrons. The majority of the time, carbon forms covalent bonds. There are many different types of bonds carbon can form.

Bonding What is bonding? What are the main types of bonding? What makes them different? So then, what’s the difference between a polar and a non-polar bond? – List an example of each. – Why then do oil and water not mix?

Hydrocarbons Hydrocarbons are compounds consisting of only hydrogen and carbon. They serve as a basis for petroleum, while not common in living organisms, many organic molecules in a cell consist of a region containing only H and C.

Organic Chemistry Organic chemistry is the study of carbon containing compounds. These compounds must also contain hydrogen to be considered organic. CO 2, CO, and CaCO 3, etc., for example, are not considered organic despite the fact that they contain carbon. The reason being, there is no hydrogen.

Carbon and Bonding Carbon also has the ability to form long chains, some of which contain double bonds. Butene, C 4 H 10 Carbon can also form ring structures as seen in benzene, C 6 H 6.

Carbon and Bonding Additionally, ball shaped carbon containing compounds called “buckeyballs” they are C-60 and are called buckeyballs.

Carbon and Bonding The diversity of carbon allows a nearly endless supply of compounds to be made, and it is this reason that carbon plays such a large and important role in biology.

Chemical Reactions Reactants get converted into products. This obeys the Law of Conservation of Mass, and the Law of Conservation of Energy.

Metabolism The sum of all chemical reactions that take place in the organism. It is the way in which a cell manages its material and energy resources.

Pathways Within the Cell Anabolic: These are the build up pathways that use starting materials to build biologically useful molecules. Catabolic: These are the breakdown pathways that use energy stored in the bonds of starting materials to drive the synthesis of energetic molecules.

Anabolic Pathways Building proteins from amino acids we obtain from eating food.

Catabolic Pathways Forming ATP from Glucose. Glucose comes from the food we eat. ATP is the energy source for the cell.

Enzymes Enzymes are used by the cell to lower the activation energy required for a chemical reaction. All enzymes are proteins. They speed up chemical reactions.

Enzymes More specifically, within a cell, enzymes are proteins that bind to a specific substrate on which the enzyme acts forming an enzyme- substrate complex.

Enzymes The enzyme- substrate complex forms an “induced” (tight) fit between the enzyme and the substrate at the active site.

Things which affect enzyme function Temperature and pH denature the protein. Cofactors help an enzyme function. – Often inorganic, metal ions are an example Coenzymes which are organic substances also help. – Often organic, vitamins are an example

Things which affect enzyme function Inhibitors--slow or stop enzyme activity – Competitive inhibitors--compete with substrate molecules for the active site of an enzyme. – Non-competitive inhibitors--bind to a spot other than the active site altering the active site slowing a reaction.