1 enzymes. brief introductory enzyme video: goofy video on how enzymes work:
Post on 11-Jan-2016
225 Views
Preview:
TRANSCRIPT
1
EnzymesEnzymes
• Brief introductory enzyme video:• https://www.youtube.com/watch?v=vTQybDgweiE • Goofy video on how enzymes work:• https://www.youtube.com/watch?v=XTUm-75-PL4
2
3
What Are Enzymes?What Are Enzymes?• Most enzymes
are Proteins Proteins ((tertiary and quaternary structures)
• Act as CatalystCatalyst to accelerate a reaction
• Not permanentlyNot permanently changed in the process
4
EnzymesEnzymes•Are specific
for what they will catalyzecatalyze
•Are ReusableReusable•End in –asease
-Sucrase-Sucrase-Lactase-Lactase-Maltase-Maltase
5
How do enzymes Work?How do enzymes Work?
Enzymes work by lowering lowering activation activation energy which energy which speeds up a speeds up a reactionreaction
6
EnzymesEnzymes
FreeEnergy
Progress of the reaction
Reactants
Products
Free energy of activationFree energy of activation
Without Enzyme
With Enzyme
7
8
Enzyme-Substrate ComplexEnzyme-Substrate ComplexThe substancesubstance
(reactant) an enzymeenzyme acts on is the substratesubstrate
EnzymeSubstrate Joins
9
Active SiteActive Site• A restricted regionrestricted region of an enzymeenzyme
molecule which bindsbinds to the substratesubstrate.
EnzymeSubstrate
Active Site
10
Induced FitInduced Fit•A change in the shapeshape of an enzyme’s active site
• Induced Induced by the substrate
11
Induced FitInduced Fit
• A changechange in the configurationconfiguration of an enzyme’s activeenzyme’s active site site (H+ and ionic bonds are involved).
• InducedInduced by the substratesubstrate..
Enzyme
Active Sitesubstrate
induced fit
12
What Affects Enzyme Activity?What Affects Enzyme Activity?
• Three factors:Three factors:
1.1. Environmental ConditionsEnvironmental Conditions
2.2. Cofactors and CoenzymesCofactors and Coenzymes
3.3. Enzyme InhibitorsEnzyme Inhibitors
13
1. Environmental Conditions1. Environmental Conditions
1. Extreme1. Extreme Temperature Temperature are the are the most dangerousmost dangerous
- - high tempshigh temps may denature denature (unfold) (unfold) the enzyme. enzyme.
2.2. pHpH (most like 6 - 8 pH near (most like 6 - 8 pH near neutral)neutral)
3.3. Ionic concentrationIonic concentration (salt (salt ions)ions)
14
2. Cofactors and Coenzymes2. Cofactors and Coenzymes
Inorganic substances Inorganic substances (zinc, iron)(zinc, iron) and vitaminsvitamins (respectively) are sometimes needed for proper enzymatic activityenzymatic activity.•Example:Example:
IronIron must be present in the quaternary quaternary structurestructure -- hemoglobinhemoglobin in order for it to pick up oxygen.pick up oxygen.
Other enzymes Other enzymes areare s sometimes needed to activate another enzyme.
Our food is made up of:• Carbohydrates: Bread, Pasta, Potato• Protein: Meat, Nuts, Lentils• Fats: Butter, Milk
Our body needs to digest them – turn them into a form that can be absorbed into the blood and used by cells. Enzymes make this possible.
Enzyme video/animation: https://www.youtube.com/watch?v=r1ryDVgx0zw
15
Enzymes that work on carbohydrates:
Salivary Amylase + Starch Maltose (in saliva) (in pasta, bread (a form of sugar that
carbohydrate) can be absorbed by the body )
16
Enzymes that work on Proteins:
Protease + Proteins Amino Acids (in stomach) (eg. In meat, nuts) (the body can absorb
them and use them)
17
Enzymes that work on Fats:
Lipase + Fats Fatty Acids + Glycerol (secreted by pancreas) (Butter, Milk) (can be
absorbed into body)
18
top related