Enzymes 1

Proteins Contain ______________________________ ______________________________ ______________________________ _________bound by ________________bonds Most also contain sulfur Some contain small amounts of phosphorus, iron, and iodine

RoleExample Enzymes control chemical reactions. Hormones regulate many physiologic processes..ex: insulin affects glucose transport into cell Hemoglobin transports oxygen and carbon dioxide in the blood. Plasma proteins transport many substances in the blood. Proteins in plasma membranes control the movement of materials into and out of the cell Protection Actin and myosin in muscle are responsible for muscle contraction StructureCollagen fibers form a structural framework in many parts of the body. Keratin adds strength to skin, hair, nails Energy Roles of Protein

Speed of Rxns __________________________________________minimum amount of energy reactants must have to start a rxn Catalysts- substances that ____________________the rate of a chemical rxn without being __________________________________________________ __________________________________________________ ____________ Enzymes- _____________________________________________ Increase the rate of rxn by - ________________________________________________ ________________________________________________ __________ Can increase rate by 1,000,000x

What Are Enzymes? ____________________ ( Most enzymes are ____________________ (tertiary and quaternary structures) Catalyst Act as Catalyst to accelerates a reaction _______________________ ______________________________________________ _______________________ changed in the process 5

Enzymes catalyze Are _____________ for what they will catalyze Reusable Are Reusable ase End in –ase-________________-________________-________________ 6

How do enzymes Work? _____________ _____________ _____________ _____________ _____________ _______ Enzymes work by _____________ _____________ _____________ _____________ _____________ _______ 7

Enzymes 8 Free Energy Progress of the reaction Reactants Products Free energy of activation Without Enzyme With Enzyme

How do enzymes work? Each enzyme has a unique 3-D shape, including a surface groove called an ________________________________________________enzyme The enzyme works by binding a specific chemical reactant (_________________________) to its _____________________________, causing the substrate to _____________________________________________________ ____________________________________________________ The resulting product (s) is then _____________from the active site. Image: Enzymatic reaction, Jerry Crimson ManniEnzymatic reaction From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Enzyme-Substrate Complex ____________ ____________ ____________ The ____________ (reactant) an ____________ acts on is the ____________ 10 Enzyme Substrate Joins

Active Site _______________________ enzyme __________________ substrate A _______________________of an enzyme molecule which __________________to the substrate. 11 Enzyme Substrate Active Site

Induced Fit ____________ A change in the ____________ of an enzyme’s active site ____________ ____________ ____________ ____________ ____________ ____________ ____________ ____________ 12

…are reusable They are not consumed (used up) in the reactions they catalyze. Enzymes… From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

The more cans (substrate), the more $ (product). The more recycling machines (enzymes), the faster the cans turn into $. Enzymes are like tiny machines within living things. From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com $ $ $ $ $ $ $

Induced Fit ______________________________ ______________________________ ______________________________ (H+ and ionic bonds are involved). Inducedsubstrate. Induced by the substrate. 15 Enzyme Active Site substrate induced fit

Formats for writing a enzymatic reaction. ( enzyme) reactant + reactant > product ( enzyme) Reactant > product + product From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

What Affects Enzyme Activity? Three factors: Three factors:

1. Environmental Conditions 1. Extreme Temperature are the most dangerous 1. Extreme Temperature are the most dangerous - ______________________________ ______________________________ 2.____________________(most like pH near neutral) 3.________________________(salt ions) 18

How do you stop an enzyme? Irreversible egg protein denaturation caused by high temperature (while cooking it). Denature It! Alteration of a protein shape through some form of external stressprotein Example, by applying heat or changing pH.pH _________________________________ _________________________________ ________________________________. From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Cofactors & Coenzymes substances (zinc, iron, copper, vitamins) _________________________ substances (zinc, iron, copper, vitamins) are sometimes need for proper enzymatic activity. Coenzyme vs Cofactor: What’s the difference? Cofactor more general term. Includes _______________________an d _______________________m olecules. _______________________m olecules Coenzyme type of cofactor, But specifically ________________________ molecules. Image: Enzyme with Cofactor, Wiki. Ribbon-diagram showing carbonic anhydrase II. The grey sphere is the zinc cofactor in the active site.Enzyme with Cofactor From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Coenzyme: Vitamin B12 Most _____________________a re coenzymes essential in helping move atoms between molecules in the formation of carbohydrates, fats, and proteins. Exclusively synthesized by ____________________ Dietary sources include meat, eggs, dairy products and supplements. Images: Streptomyces spores, Wiki; Vitamin B12 chemical structure, WikiStreptomyces sporesVitamin B12 chemical structure From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Two Types of Enzyme Inhibitors 1._________ _________ _________ Chemicals that _______________ _______________ _______________ and _______________ with it for the active site. Reversible depending on concentration of inhibitor and substrate. Image: Competitive inhibition of enzyme, Jerry Crimson MannCompetitive inhibition EXAMPLE: The drug Antabuse is used to help alcoholics quit drinking. Antabuse inhibits aldehyde oxidase, resulting in the accumulation of acetaldehyde (say a-si-’tell-de-hide) during the metabolism of alcohol. Elevated acetaldehyde levels cause symptoms of nausea and vomiting. From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Two Types of Enzyme Inhibitors 2. Non-competitive Inhibitor 2. Non-competitive Inhibitor ______________ _______________________ Usually r eversible, depending on concentration of inhibitor & substrate. EXAMPLE: You may know that compounds containing heavy metals such as lead, mercury, copper or silver are poisonous. This is because ions of these metals are non-competitive inhibitors for several enzymes. Image: Pouring liquid mercury, BionerdPouring liquid mercury From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Enzyme Inhibitors _________________ _________________ Many medications are enzyme inhibitors. Enzyme inhibitors are also used as herbicides and pesticides Images: Prescription bottle, T. Port; Dead cockroach, WikiDead cockroach EXAMPLE: Another example of competitive inhibition is protease inhibitors. They are a class of anti- retroviral drugs used to treat HIV. The structure of the drug ritonavir (say ri-TAHN-a-veer) resembles the substrate of HIV protease, an enzyme required for HIV to be made. From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Meet the Enzyme : _______________ ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ Involved in ___________________ of adenosine triphosphate (ATP), from:ATP - adenosine diphosphate (ADP) - a phosphate group and - energy from H+ ion gradient ATP is the most commonly used "energy currency" of cells. Reaction: ( ATP synthase) ADP + Pi  ATP substratesubstrate product Images: ATP synthase diagram, Tim VickersATP synthase diagram From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Meet the Enzyme : ______________ Catecholase is present in most fruits and vegetables It is the enzyme that facilitates the browning of cut or bruised fruits and vegetables by catalyzing the following reaction: catecholase _____________+ _____________  ________ colorless substrate brown product Image: Bananas T. Port From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Meet the Enzyme : Catecholase Lemon juice and other acids are used to preserve color in fruit, particularly apples, by lowering the pH and removing the copper (cofactor) necessary for the enzyme to function. Reaction: catecholase catechol + O  polyphenol colorless substrate brown product Images: Apples, T. Port; Lemons, André Karwath; Enzyme with Cofactor, Wiki; pH scale, Edward Stevens, WikiLemonsEnzyme with CofactorpH scale From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Meet the Enzyme : ________________ Pineapple contains enzyme bromelain, which can digest protein Jell-O ® is made of gelatin, a processed version of a structural protein called collagen found in many animals, including humans. Collagen = big, fibrous molecule makes skin, bones, and tendons both strong and elastic. Gelatin you eat in Jell-O ® comes from the collagen in cow or pig bones, hooves, and connective tissues. (Yummie!) Examine 2 containers: a. In one, canned pineapple was used to make Jell-O ®. b. The other, fresh pineapple was used. Q: Why is one Jell-O solid and the other liquid? Image: Pineapple, Whaldener EndoPineapple From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

Meet the Enzyme : ___________________ (bromelain) ____________+ _____  _________ substrate products Bromelain is a __________________ enzyme that facilitates hydrolysis of protein.enzyme Remember, hydrolysis cuts molecule by adding water…the reverse of the hydration synthesis pictured to the left. FYI: Bromelain is used as a meat tenderizer. Breaks down the collagen in meat. So what do you think could happen to your tongue when you eat fresh pineapple? From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com