| Question |
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| Answer |
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| What is the structure of an enzyme? |
The structure can have one or two parts: apoenzyme & coenzyme (or cofactor); both parts together=holoenzyme(whole) |
| Apoenzyme |
Always present, have highly specific protein part, different for every kind of enzymes (all enzymes have it) |
| Coenzyme or Cofactor |
Part of most enzymes, needed to activate the epoenzyme, not specific, same one can activate many different enzymes; coenzymes (organic)-often a vitamin, cofactor (inorganic)-a mineral |
| What is the function of an enzyme? |
To speed up reactions by bringing specific substances into proper orientation (position) so the reaction can take place rapidly; lower energy of activation of a reaction |
| What is a substrate? |
The substance upon which an enzyme reacts |
| What is a product? |
What the substrate is changed into (as a result of the enzyme-facilitated reaction) |
| What factors influence enzyme function? |
Temperature, pH, concentration of the substrate, enzyme inhibitors ( competitive inhibitors & noncompetitive) |
| Competitive Inhibitors |
Directly bind to the active site of the enzyme, preventing the substrate from entering and being converted to product (reaction stops) |
| Noncompetitive Inhibitors |
Bind to another site of the enzyme, causing a change in the shape at the active site, into which the substrate can no longer fit (reaction stops) |
| What is a coenzyme? |
Name used if that second part is an organic molecule (often a vitamin) |
| What is a cofactor? |
Name used if that second part is an inorganic molecule (a mineral) |
| What is a holoenzyme? |
Both parts (apoenzyme & coenzyme/cofactor) together;whole |
| Exoenzymes |
A class of enzymes that is released to the external of the cell and wok outside (ex. digestive enzymes and enzymes of virulence) |
| Endoenzymes |
A class of enzymes that remains inside of the cell and work internally (ex. enzymes of cellular metabolism) |
| Constituitive Enzymes |
A class of enzymes that is always present, necessary for life; quantity independent of amount of substrate (ex metabolic enzymes) |
| Induced Enzymes |
A class of enzymes that is produced only as needed (when substrates are present) providing efficiency and adaptability; quantity of enzymes is dependent on the mount of substrate (ex induced enzymes) |
| What is the process by which macromolecules are broken down into smaller molecules? |
Hydrolysis; digestion is always hydrolysis; General Formula: A-B + H-OH →A-OH + H-B (adding H20 to break apart) |
| Describe how an enzyme works. |
An enzyme works as a catalyst to speed up a reaction that would otherwise take too long or never happen at all. The enzyme will attach to a substrate and form an enzyme substrate complex which then produce a product at the completion of the enzyme reactio |
Biology Lab Midterm
