Enzymes - Chemistry 107

Describe enzymes and their role in enzyme-catalyzed reactions

• accelerate chemical reactions

• lowers activation energy needed for the reaction to occur

What are the seven types of enzymes and what are their names?

• Oxidoreductases - catalyzes oxidation-reduction reactions

• Transferases - transfer a functional group from one molecule to another

• Hydrolases - break a chemical bond by adding a molecule of water

• Lyases - break chemical bonds in a way that forms a double bond or adds a group to a double bond w/o the use of water

• Isomerases - rearrange the atoms within a molecule to form an isomer

• Ligases - join two molecules together to form a larger one, often with the use of ATP

• Translocases - catalyze the movement of ions or molecules across a membrane

Describe the effects that changes of temperature, pH, enzyme concentration, and substrate concentration have on enzyme activity

• Temperature affects the speed of molecules.

• Low temperature - slow, high temperature - fast, too high causes denaturation, which creates a dramatic drop in activity. optimum temperature, the molecule is moving at maximum rate

• pH affects the activity of the enzyme

• optimum pH - enzyme is most active, too high or too low - enzyme ceases all or most activity due to severely altered structure

• Concentration determines reaction rate

• high concentration - faster reaction rate (if substrate is in sufficient amount)

• Substrate also determines reaction rate

• Has a saturation point where it will reach its maximum, and adding any more substrate will not increase the reaction rate.

Describe the role of allosteric enzymes, feedback control, and covalent modification in regulating enzyme activity

Allosteric enzymes