ENZYMES….. The protein catalyst Learning targets: I can: Define what an enzyme is and explain its role in the body Explain and Identify the parts of the Lock and key model Describe the environmental conditions that alter the shape of an enzyme Name/identify an enzyme based on its substrate smp2016

Enzyme video Amoeba sisters video: https://www.youtube.com/watch?v=qgVFkRn8f10 smp2016

Chemical Reactions Reactants Products 2 H2 + O2 2 H2O Reactants- things that start the reaction (left side of arrow). Products- things that are produced (right side of arrow). 2 H2 + O2 2 H2O smp2016

I. What is an Enzyme? Organic catalysts made of proteins ALL Enzymes are proteins (chains of amino acids folded into a specific shape). Catalyst: substance that speeds up the rate of a chemical reaction by lowering the activation energy needed to start it without being altered or used up during the reaction May be organic or inorganic (water) smp2016

Most enzymes end in -ase Enzymes are named according to the substrate they are specific to Examples: Maltase binds to maltose Lactase binds to lactose Lipase breaks down fat Amylase is found in saliva smp2016

II. Functions of Enzymes in living things Help to release energy (cellular respiration) in the form of ATP to the cells so they can carry on metabolic activities (& life functions) DIGESTION (breakdown) and SYNTHESIS (building up) of molecules PHOTOSYNTHESIS (capturing energy) smp2016

III. Enzyme Terms: Substrate: Molecule an enzyme acts upon Usually the enzyme is larger than the substrate (reactant) Active Site: Region on the enzyme that fits exactly with the substrate and where the chemical reaction occurs Coenzymes such as vitamins can combine with an enzyme so the substrate will fit into the active site better. smp2016

IV. How Enzymes Work: The Lock & Key Model of Enzyme Action http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html DEMO The enzyme has an active site on its surface which has a very specific shape which determines its function. this is known as ENZYME SPECIFICTY. Ex: Salivary Amylase Reacts with starch but not protein smp2016

The enzyme and the substrate temporarily join together forming the ENZYME SUBSTRATE COMPLEX smp2016

Each ENZYME is SPECIFIC for ONLY one SUBSTRATE (like a lock and key) Once the E-S Complex is formed, the enzyme reaction takes place. Upon completion of the reaction, the enzyme and product(s) SEPARATE, and the enzyme can be RECYCLED (REUSED) smp2016

Substrate Product Digestion reactions smp2016

Digestion reaction Digestion reactions Starch amylase Many Simple Sugars smp2016

Substrate Product Synthesis Reaction Active site smp2016

Glucose or Simple Sugars Synthesis reaction Glucose or Simple Sugars amylase Starch smp2016

V. Factors Limiting Enzyme Action Denature – change in the SHAPE of the enzyme the active site can’t bind with the substrate and the reaction rates decrease or may stop all together This is due to strong acids (low pH) or bases (high pH) and high temperatures Loss of SHAPE = Loss of FUNCTION smp2016

Each type of enzyme require optimum (best) conditions 1. pH: dependent on location. Pepsin works best in a pH of 3 in stomach Tryspin works best in a pH of 7.8 in small intestine stomach Small intestine

2. Temperature: Humans: best at 37°C Why do we get a fever when we get sick? b/c high temps denature (change) the shape of the enzyme and stops it from working smp2016

3. Concentration of Enzyme and Substrate Enzyme rate also depends on the amount of enzyme and substrate Little enzyme, lots of substrate: Slower rates How can we speed up the rate? Add more enzyme until max. rate achieved. smp2016

Let’s practice some regent’s questions: 1. All chemical breakdown processes in cells directly involve  reactions that are controlled by catalysts enzymes that are stored in mitochondria the production of catalysts in vacuoles enzymes that have the same genetic base sequence 2. Which statement best describes the enzyme represented in the graphs? This enzyme works best at a temperature of 35°C and a pH of 8. This enzyme works best at a temperature of 50°C and a pH of 12. Temperature and pH have no effect on the action of this enzyme. This enzyme works best at a temperature above 50°C and a pH above 12 smp2016

This diagram best illustrates the relationship between 3. The diagram below represents a series of reactions that can occur in an organism. This diagram best illustrates the relationship between enzymes and synthesis amino acids and glucose antigens and immunity ribosomes and sugars enzyme smp2016

4. The diagram illustrates a biochemical process that occurs in organisms.  The substance labeled "catalyst" is also known as a hormone an enzyme an antibody an inorganic compound 5. The effect of temperature on the relative rate of action of an enzyme is represented in the graph. The optimum temperature for the action of this enzyme is approximately 15°C 22°C 37°C 50°C You should never guess-draw the line to help you smp2016

Base your answer on the reactions shown in the graphic Base your answer on the reactions shown in the graphic. The X in each reaction represents various energy sources final products reactants enzymes Glucose is the reactant (substrate) Right side of arrow is the product smp2016

Enzyme song https://www.youtube.com/watch?v=deFQhPurj-k smp2016