ENZYMES Enzymes are what type of biological molecule

ENZYMES Enzymes are what type of biological molecule? What is their monomer?

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

Fireflies

l. ENZYMES are biological catalysts. l. 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) l. Speeds up reaction 10 million X.

Activation energy

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

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

IF YOU’RE A “HOW” PERSON (you do not need to know this!) 1. The enzyme may hold the substrates in such a way as to distort the substrate bonds closer to their form in the transition state. This reduces the amount of energy needed to complete the transition. 2. The enzyme may create a charge distribution opposite to that of the transition state. This lowers the energy of the transition state and decreases the activation energy. 3. The enzyme may reduce the reaction entropy ΔS‡ by bringing substrates together in the correct orientation to react. 4. The enzyme may provide a completely different chemical pathway for the reaction. It may form new bonds in the ES complex that would be difficult to form without the enzyme

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

Remember… its actually like this

How do Enzymes and Substrates Fit? l One substrate fit into active site of only one enzyme l Lock and Key theory

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

Use your power of observation… What do all these Enzymes have in common? Urokinase Hyaluronidase DNA topoisomerase-II Endonucleases Cyclo-oxygenase Acetyl cholinesterase Monoamine oxidase Oxidases Hydrolases DNA dependent RNA polymerase Reductases Lyases Ligases Isomerases Glucuronidase Transaminases Glycogen synthase Aminoacyl t. RNA synthetase Lactate dehydrogenase

Enzymes in the Human Body

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

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

Temperature

p. H

CONCENTRATION l 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 l Listen for example!

Substrate Concentration

CONCENTRATION l Concentration- how much of a substance is present ¡ Enzyme Concentration- if there are more enzymes the reaction with occur faster as long as there is enough material l Listen for example!

Enzyme Concentration l NOT EXACTLY CORRECT!! Listen for why!

INHIBITORS l 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

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