Question

how enzymes work
in the diagrams below do the following:

1. label the active site of the enzyme
2. label and colour the enzyme blue
3. label and colour the substrate red
4. label and colour the product green

key ideas
words to use
complex low product biological thousands
active site complementary activation
unchanged specific catalyse substrate

1
diagram 1
enzymes are known as ________ catalysts. the enzyme has an ______ which the substrate molecule is able to fit into. the substrate molecule is said to have a ______ shape to the enzymes active site. enzymes are said to be ______ to just one ________ for this reason.

2
diagram 2
when the substrate and enzyme molecules temporarily combine it is known as an enzyme - substrate ________. as the enzyme holds the substrate molecule in a certain way it puts tension on the substrate molecule. this lowers the ______ energy needed for the reaction to take place. this is why reactions can occur at relatively ________ temperatures in living things.

3
diagram 3
during the reaction the substrate is turned into ________. this is released from the enzymes active site and the enzyme molecule is left ______ and free to ______ more reactions. each reaction in our body involves a specific enzyme. we have ________ of different enzymes in our body.

Explanation:

To solve the fill - in - the - blanks about enzyme work, we use the knowledge of enzyme function:

For the first paragraph (about enzyme basics):

• Enzymes are biological catalysts as they work in living organisms.
• Enzymes have an active site where the substrate fits.
• The substrate has a complementary shape to the enzyme's active site.
• Enzymes are specific to just one substrate (lock - and - key or induced - fit model).

For the second paragraph (enzyme - substrate complex and activation energy):

• When substrate and enzyme combine, it's an enzyme - substrate complex.
• Enzymes lower the activation energy of the reaction.
• This allows reactions to occur at relatively low temperatures in living things.

For the third paragraph (product formation and enzyme reuse):

• During the reaction, the substrate is turned into product(s).
• The enzyme molecule is left unchanged after the reaction.
• The enzyme is free to catalyse more reactions.
• Our body has thousands of different enzymes.

Answer:

1. Enzymes are known as \underline{biological} catalysts. The enzyme has an \underline{active site} which the substrate molecule is able to fit into. The substrate molecule is said to have a \underline{complementary} shape to the enzyme's active site. Enzymes are said to be \underline{specific} to just one \underline{substrate} for this reason.
2. When the substrate and enzyme molecules temporarily combine it is known as an enzyme - substrate \underline{complex}. As the enzyme holds the substrate molecule in a certain way it puts tension on the substrate molecule. This lowers the \underline{activation} energy needed for the reaction to take place. This is why reactions can occur at relatively \underline{low} temperatures in living things.
3. During the reaction the substrate is turned into \underline{product(s)}. This is released from the enzyme's active site and the enzyme molecule is left \underline{unchanged} and free to \underline{catalyse} more reactions. Each reaction in our body involves a specific enzyme. We have \underline{thousands} of different enzymes in our body.