Organic Reactions and Enzymes

Warmup (9/22) Watch the video and answer the following questions http://www.youtube.com/watch?v=9X-BtcjOTus  What is the purpose of pasteurization? Describe two types of pasteurization. Why is it important to eat whole (raw) fruits and vegetables? Why are preservatives added to juice, even after pasteurization?

Enzymes Are PROTEINS Function as Biological catalysts (get reaction started!) Speed up the reaction by lowering the activation energy (Catalysts).

Enzyme action Enzymes have a particular shape. Provides a “binding site”, a place where the substrate (reactant) fits in like a lock and key then the reaction happens Shape of enzyme’s binding (active) site is very specific—only fits one substrate

Enzymes are Sensitive! Specific conditions are required for an enzyme to function: Most will only work within a particular range of: Temperature pH (acidity) At high temperatures, an enzyme may degrade (break down). (Think pineapple and Jell-O) This helps to regulate enzyme function Enzymes only cause the reaction to happen when the conditions are right. Human body?

How enzymes are named Each is usually named for the reaction it catalyzes Protease = breaks down protein Anhydrase = removes water If you know the name, you can often figure out the function!

Enzymes Are specific for what they will catalyze Are Reusable End in –ase -Sucrase -Lactase -Maltase http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html

Chemical Reactions Changing of one set of chemicals into a new set of chemicals A chemical change Always involve the breaking of chemical bonds and/or the formation of new bonds Examples: CH4 + O2  CO2 + H2O (This is not balanced)   2H2 + O2 2H2O

Intro to enzymes http://ffh.films.com/PreviewClip.aspx?id=17163

How do enzymes Work? Enzymes work by weakening bonds which lowers activation energy

HOW ENZYMES WORK Enzymes are ORGANIC CATALYSTS. A CATALYST is anything that speeds up a chemical reaction that is occurring slowly. How does a catalyst work? The explanation of what happens lies in the fact that most chemical reactions that RELEASE ENERGY (exothermic reactions) require an INPUT of some energy to get them going. The initial input of energy is called the ACTIVATION ENERGY

Energy in Reactions Reactions can release or absorb energy Reactions that release energy (exothermic)can occur spontaneously, however, many need Activation energy Activation energy is energy needed to get a reaction started

Enzymes Without Enzyme With Enzyme Free Energy Progress of the reaction Reactants Products Free energy of activation

Energy in reactions cont. Chemical reactions that absorb energy (endothermic) generally need much activation energy

pH Scale Let’s get pHunky brothers and sisters! Let’s get pHunky

You may know… Chemists measure how acidic or basic a substance is with… The pH scale Acid and base strength is measured on a pH scale that ranges from 0 to 14 Neutral solutions have a pH = 7 Acidic solutions have a pH < 7 Basic solutions have a pH > 7 I’m pHeeling it mamma…

It’s the pOWER of Hydrogen, phools! Acids These substances have extra H+ ions Below 7 = acid pH indicates the amount of Hydrogen ions in a solution It’s the pOWER of Hydrogen, phools!

Bases These solutions have fewer H+ in the substance (and more OH- ions) Base is anything > 7 Aka alkaline Neutral substances= 7

pHun with the pH scale Just remember this brothers and sisters: ABBA

You called? Oh! Acids Below Bases Above ?

Why is this chemistry important in biology class? Your body- HOMEOSTASIS!!!!!!!! Stomach acids help digest food Blood – pH of about 7 (neutral) Enzymes function only at specific pH Homeo…what??

Why is this chemistry important in biology class? Environment Acid rain Water pollution Take me to pHunky town

Acid Rain Effects This is too pHunky, even for me!

Did you get your learn on? Don’t pHreak out, you don’t wanna pHail this test!

Application : How does pH affect an enzyme? Look at “Analyzing Data” section on page 51 in your textbook. Answer questions #1-6

Homework (due Wed 9/28) Write out the answers to all Chapter 1 and 2 Learning Targets Must write in complete sentences Do this in your lab book, after the McMush conclusion questions