Objective: Students will be able to identify the different structures of proteins and their functions. Students will be able identify the limits of enzymes.

Fireflies Luciferin heat + light luciferase

Enzymes Are biological catalysts. Catalyst - a substance that speeds up chemical reactions in cells. - HOW? They lower the activation energy (activation energy- amount of energy required for a reaction to occur) Speeds up reaction 10 million X.

Activation energy

How do they work? The reactants are known as substrates (what is being broken or built) Enzymes provide a site(space) where substrates can be brought together to react. (like a docking station) This binding region on the enzyme is called the active site.

How do they work? When substrates are brought together at the active site the form a short-lived enzyme –substrate complex. Once the reaction has occurred, and the product is formed, the enzyme is released from the complex and restored to its original state. The enzyme can work again and again.

The enzyme goes back to starting state and works again and again

How do Enzymes and Substrates Fit? Originally scientists thought that enzymes and substrates came together the way a key fits in a lock. One substrate fit into active site of only one enzyme Lock and Key theory

Enzyme Specificity Enzymes are picky! Each enzyme catalyzes only one reaction. For example, there is a specific enzyme that breaks maltose down into 2 glucose molecules. B/C this is the only reaction this enzyme carries out- called maltase Many enzymes are named this way replacing suffix with –ase.

Name that Enzyme!!! The enzyme that breaks down maltose is maltase Using this model name the following: Bind DNA polymers= _______________ Breaks down Cellulose= ____________ Produces telomeres= ___________

Regulation of Enzymes Can be affected by: pH - needs to be stable. Usually neutral but there are exceptions Pepsin, digestive enzyme pH 2 Enzymes are active over narrow range of pH. temperature - enzymes in the human body work best at 37 C - normal body temperature. Concentration of substrates Inhibitors Competitive and non-completive

CONCENTRATION Concentration- how much of a substance is present Substrate Concentration- if there is more of a substance/material then the enzyme can work as fast as possible with the available resources Listen for example! __________________________ ___________________________________________ Enzyme Concentration- if there are more enzymes the reaction with occur faster as long as there is enough material

INHIBITORS Inhibitors-a molecule that attaches to the enzyme, not allowing the substrate to attach Competitive inhibitor-mimic substrate and physically block active site Noncompetitive inhibitor-attaches to enzyme somewhere other than active site, but changes active site so substrate is unable to fit into active site

Temperature

pH

Enzyme Concentration NOT EXACTLY CORRECT!!Listen for why!

Substrate Concentration

Enzymes are important in: 1. Regulating chemical pathways. 2. Making materials that the cell needs. 3. Releasing energy. 4. Transferring information.