BIOL 1406
PreLab 6.1
What are enzymes?
Enzymes are organic molecules (usually proteins) that act to speed up
specific chemical reactions. Without the necessary enzyme, most reactions within
a cell take place so slowly as to be insignificant. Therefore, by controlling
which enzymes are made, the DNA of a cell controls which chemical
reactions take place.
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Use the interactive exercise below to learn more about enzymes. |
In this lab you will analyze the effects of substrate concentration,
temperature, pH, substrate identity, and the presence or absence of cofactors on
enzyme activity. The first enzyme you will study is glucose oxidase. This enzyme
can be commercially prepared and is routinely used to determine blood glucose
levels. Abnormal levels of glucose in the bloodstream may be an indication of a
variety of disorders, such as diabetes, hypoglycemia, insulin overdose, liver
disease, or diseases of the thyroid or adrenal glands. The other enzyme that you
will study is catecholase. Catecholase is found in many fruits and vegetables,
and is responsible for the “browning” that occurs when these fruits and
vegetables are cut or bruised.
| Your Turn | |
| 1. How does DNA control which reactions take place within a cell? | Check your answer. |
| 2. Enzymes speed up reactions by binding to reacting molecules, called: | Check your answer. |
| 3. The part of an enzyme where substrates attach is called: | Check your answer. |
| 4. How do temperature and pH act to affect enzyme activity? | Check your answer. |
| 5. How does substrate concentration act to affect enzyme activity? | Check your answer. |
| 6. What is the Vmax of an enzyme? | Check your answer. |
| 7. Which 2 enzymes will you study in this lab? | Check your answer. |
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