Enzymes

What type of Biomolecule are Enzymes? Proteins! What is the monomer for proteins? Amino Acids! What type of bond holds amino acids together? Peptide!

Enzymes act as catalysts for reactions in the body (catalysts speed up reactions) They do this by lowering the amount of energy that is needed to start a chemical reaction (which is called activation energy)

Enzymes can be reused again and again because they do not change during the reactions they affect Enzyme names end in –ase such as Lactase, Amylase enzyme enzyme enzyme

The molecules that are going to react/change are called the substrate They attach to the enzyme on a spot called the Active Site Substrate Products Active site enzyme enzyme enzyme enzyme

There are 2 theories to how substrates attach to enzymes: 1) Lock and Key: the substrate fits perfectly into the enzyme like a key into a lock

There are 2 theories to how substrates attach to enzymes: 2) Induced Fit: The enzyme is flexible and changes to work for the shape of the substrate

Inhibition Inhibition is when an enzyme is made inactive or dysfunctional by something else. (This is used a lot in medicines) There are two types: Competitive inhibition – something binds to the active site and blocks the substrate from binding

Inhibition Inhibition is when an enzyme is made inactive or dysfunctional by something else. (This is used a lot in medicines) There are two types: 2) Non-competitive inhibition – something binds to a different spot on the enzyme and makes it change shape

Conditions for Enzymes If enzymes are denatured (unfolded) due to a change in pH or temperature, their activity decreases All enzymes have optimal conditions where they will work the best The human body must have a consistent pH and temperature so all of our enzymes can function and our body can work.

Changing Concentrations Increasing the substrate concentration will increase the speed of the reaction until all enzymes are being used (this is called the point of saturation) Increasing the enzyme concentration will increase the reaction rate again

Questions What are enzymes? How do enzymes affect rate of reaction? How does a catalyst speed up a reaction? Can an enzyme be reused? What would happen to a reaction if the enzyme is removed? If an inhibitor binds to an enzyme on the active site, what type of inhibitor is it? If the substrate binds to the enzyme perfectly at the active site, what is this theory called? If an inhibitor binds to an enzyme on a different site, what type of inhibitor is it? If the enzyme has to change its shape to fit the substrate, what is this theory called? If substrate concentration is saturated, can the enzyme activity increase? If substrate concentration is saturated, what needs to be added in order for enzyme activity to increase?