Ap Bio Review Topic 3 and 6

Identify two conditions that affect the structure of an enzyme. A.What happens to the structure of the enzyme in these conditions?

Enzyme activity can be affected by a variety of factors, such as temperature, pH, and concentration. A. Proteins change shape as temperatures change. Because so much of an enzyme's activity is based on its shape, temperature changes can mess up the process and the enzyme won't work.

What is the function of an enzyme?

Enzymes create chemical reactions in the body. They actually speed up the rate of a chemical reaction to help support life. The enzymes in your body help to perform very important tasks. These include building muscle, destroying toxins, and breaking down food particles during digestion.

True or False? Enzymes affect the Gibbs Free Energy of a chemical reaction.

Enzymes do not affect the Gibbs free energy of a reaction. That means that they do not increase or decrease how much products are formed and how much reactants are used up nor do they increase or decrease the free energy values of the products and reactants. Enzymes affect the activation energy by lowering it.

How is the reaction rate of an enzyme-catalyzed reaction and an uncatalyzed reaction different?

The reaction rate for an enzyme-catalyzed reaction is faster then the uncatalyzed reaction.

What is an enzyme-catalyzed reaction?

The reactions are: Oxidation and reduction. Enzymes that carry out these reactions are called oxidoreductases. For example, alcohol dehydrogenase converts primary alcohols to aldehydes.

What happens after the substrate binds to the enzyme?

When an enzyme binds its substrate, it forms an enzyme-substrate complex. This complex lowers the activation energy of the reaction and promotes its rapid progression by providing certain ions or chemical groups that actually form covalent bonds with molecules as a necessary step of the reaction process. One of the important properties of enzymes is that they remain ultimately unchanged by the reactions they catalyze. After an enzyme is done catalyzing a reaction, it releases its products (substrates).

What is the monomer that makes up an enzyme?

Amino Acids

How is the change in free energy of an enzyme-catalyzed reaction and an uncatalyzed reaction different?

An enzyme helps catalyze a reaction by decreasing the free energy of the transition state. As a result, more product will be made because more molecules will have the energy necessary for the reaction to occur and the reaction will occur at a faster rate.

How does an enzyme affect the rate of biological reactions?

Enzymes are biological catalysts. Catalysts lower the activation energy for reactions. The lower the activation energy for a reaction, the faster the rate. Thus enzymes speed up reactions by lowering the activation energy.

How does the enzyme complete this function?

Enzymes work by binding to reactant molecules and holding them in such a way that the chemical bond-breaking and bond-forming processes take place more readily.

How does a substrate bind to an enzyme?

For an enzyme and substrate to bind they have to fit together physically. Each enzyme has a region on its surface called the active site. This is a cleft in the protein surface where the substrate binds. It has a shape that fits the substrate like a glove fits a hand or a lock fits a key.

How is the activation energy of an enzyme-catalyzed reaction and an uncatalyzed reaction different?

The uncatalyzed reaction proceeds via a one-step mechanism (one transition state observed), whereas the catalyzed reaction follows a two-step mechanism (two transition states observed) with a notably lesser activation energy.