Download presentation
Presentation is loading. Please wait.
Published byKatherine Long Modified over 9 years ago
2
Enzymes: Biological Catalysts – Chemical Reaction “helpers”
3
Energy flows through life Life depends on chemical reactions
4
Regents Biology Enzymes lower the energy needed for a chemical reaction to occur!
5
Regents Biology See!!! Energy is lowered!!! AA + AA Protein WITH AN ENZYME!!!
6
Nothing works without enzymes! How important are enzymes? Every chemical reaction that occurs in a living organism is controlled by a specific enzyme. building molecules synthesis enzymes breaking down molecules digestive enzymes ++ enzyme We can ’ t live without enzymes!
7
synthesis digestion ++ enzyme Enzymes speed up reactions
8
Each enzyme is the specific helper to a specific reaction enzymes are named for the reaction they help sucrase digests sucrose proteases digests proteins lipases digests lipids DNA polymerase synthesizes DNA Oh, I get it! They end in -ase
9
It’s SHAPE that matters! Enzymes are large PROTEIN molecules that have a distict shape on their outer surface. shape of protein/enzyme allows substrate (reactant) substrate (reactant) to fit ONE substrate each enzyme is specific for ONE substrate
10
One lock: One key…Lock and Key Model!
11
Enzymes aren’t used up!! Enzymes are NOT CHANGED by the reaction Used only temporarily Re-used again for the same reaction with other substrates Therefore, very little enzyme is needed to help in the life processes reactions enzyme substrateproduct active site
12
1 2 3
13
Coenzymes Sometimes an enzyme needs a COENZYME in order to work. Coenzymes are usually vitamins! Inactive Enzyme Active Enzyme Active Enzyme converts substrate to products
14
Enzyme Vocabulary Enzyme Biological Catalyst that makes reactions happen Substrate Reactant molecule that enzymes work on Enzyme-substrate complex enzyme & molecule temporarily joined Active site part of enzyme that substrate molecule fits into Coenzyme Usually a vitamin that activates the enzyme
15
Regents Biology
16
More about Enzymes: Factors influencing enzyme action
17
Enzyme Concentration Affects the rate of enzyme activity an increase in the amount of enzyme = an increase in how fast the reaction happens more enzymes = more frequent collisions with substrate = faster rate of reaction
18
Enzyme Concentration amount of enzyme reaction rate What’s happening here?!
19
Substrate concentration Affects the rate of enzyme activity an increase amount of substrate = an increase in how fast the reaction happens more substrate = more frequent collisions with enzyme = faster rate of reaction
20
Substrate concentration amount of substrate reaction rate What’s happening here?!
21
Regents Biology Can You Stop Enzyme Action? If an enzyme just kept going and going…synthesizing and digesting every molecule in your body… BIOLOGICAL CHAOS!!! Our bodies need to control enzymes HOW?????
22
Controlling Enzyme Action Enzymes have to be right shape to work! Two factors affect SHAPE: 1. Temperature 2. pH (acids & bases)
23
Temperature Optimum temperature – not too hot, not too cold! greatest number of collisions between enzyme & substrate…lots of binding happening! human enzymes = 35-40°C (body temp = 37°C)
24
Temperature Increase in temperature Denatures the protein = protein loses shape = active site no longer fits the substrate! Decrease in temperature molecules move slower decrease collisions
25
37° Temperature temperature reaction rate What’s happening here?!
26
Temperature Why are fevers dangerous?
27
pH pH changes protein shape Each enzyme functions best at a specific pH MOST human enzymes = pH 6-8 (depends on location in body!) pepsin (stomach)=pH 3 trypsin (small intestine)=pH 8
28
pH EnzymepH Optimum Lipase (pancreas)8.0 Lipase (stomach)4.0 - 5.0 Lipase (castor oil)4.7 Pepsin1.5 - 1.6 Trypsin7.8 - 8.7 Urease7.0 Invertase4.5 Maltase6.1 - 6.8 Amylase (pancreas)6.7 - 7.0 Amylase (malt)4.6 - 5.2 Catalase7.0
29
7 pH reaction rate 20134568910 stomach pepsin intestines trypsin What’s happening here?! 11121314
30
Regents Biology If pancreatic lipases were located in the stomach, what would happen to the effectiveness of the enzyme? Why?
31
For enzymes… What matters? SHAPE!
32
Regents Biology "Neither vitamins, minerals or hormones can do any work -- without enzymes.” -Dr. Edward Howell
33
Regents Biology Other Factors that influence enzyme action: Activators make enzymes work harder and faster
34
Regents Biology Inhibitors Inhibitors either slow down or stop the activity of an enzyme. They often bond to the protein, changing the overall shape of the enzyme.bond ex: snake venom or nerve gas
35
Regents Biology Animal Study: Enzyme Inhibition Protects Against Huntington's Disease Damage by Kathy Jones on December 03, 2012 at 6:41 PM Data from a study involving two animal models of Huntington's disease indicates that treatment with a novel agent that inhibits the activity of an enzyme called SIRT2 reduced neurological damage, slowed the loss of motor function and extended survival. SIRT2 is an enzyme that regulates many important cellular functions. The study led by Massachusetts General Hospital (MGH) researchers will appear in the Dec. 27 issue of Cell Reports and is receiving advance online release.
36
Regents Biology Enzymes play a critical role in everyday life. Many heritable genetic disorders (diabetes, Tay-Sachs disease) occur because there is a deficiency or total absence of one or more enzymes. Other disease conditions (cancer) result because there is an excessive activity of one or more enzymes. Routine medical tests monitor the activity of enzymes in the blood, and many of the prescription drugs (penicillin, methotrexate) exert their effects through interactions with enzymes. Enzymes and their inhibitors can be important tools in medicine, agriculture, and food science.methotrexate Protease enzymes are used in 'biological' washing powders to speed up the breakdown of proteins in stains like blood and egg. Read more: http://www.biologyreference.com/Dn- Ep/Enzymes.html#ixzz2EODvisB7http://www.biologyreference.com/Dn- Ep/Enzymes.html#ixzz2EODvisB7
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.