Ch. 2 Quiz on Monday 9/8 Notebook Check on Wed 9/10 Sponge: Set up Cornell Notes on pg. 17 2.5 Enzymes Essential Question: How does a catalyst affect the activation energy of a chemical reaction? 2.5 Enzymes How does a catalyst affect the activation energy of a chemical reaction? KEY CONCEPT Enzymes are catalysts for chemical reactions in living things. Ch. 2 Quiz on Monday 9/8 Notebook Check on Wed 9/10

KEY CONCEPT Enzymes are catalysts for chemical reactions in living things.

Who would win this race? Why? Finish Line Team #1 Team #2

Catalysts are substances that speed up chemical reactions. decreases or lower activation energy Therefore, increasing the reaction rate

Catalysts (1 video) Enzymes (2 videos) 7 bullets 5 bullets Pg. 16 –Split in 1/3s Catalysts (1 video) Enzymes (2 videos) 7 bullets 5 bullets Catalyst drawing Hemotoxins Neurotoxins

Catalyst Video

Enzymes: A Fun Introduction Video 4m45s

Enzymes are catalysts in living things. Enzymes are needed for almost all processes. Breaking down food and building proteins Most enzymes are proteins.

Enzymes and Digestion Video

Without a catalyst Activation energy

With a catalyst the reaction starts faster!!!!!! Activation energy

Activation energy without a catalyst Activation energy with a catalyst Draw this picture on the middle 1/3 of pg. 16 to show how catalysts speed up chemical reactions Activation energy without a catalyst Activation energy with a catalyst

How does a catalyst affect the activation energy of a chemical reaction?

Answer Decreases the activation energy needed to start a chemical reaction AND also increases the rate of the chemical reaction.

An enzyme’s function depends on its structure (shape) An enzyme’s structure allows only certain reactants to bind to the enzyme. Substrates- the specific reactants that enzymes act on Bind at active sites substrates (reactants) enzyme Substrates bind to an enzyme at certain places called active sites. Ex: Amylase- ONLY breaks down starch Starch is the substrate for amylase Ex: Lactase ONLY breaks down lactose Lactose is the substrate for Lactase

Changes in temperature and pH can affect the shape and function, or activity of an enzyme If the enzyme shape changes it loses its ability to function!!!! Like a puzzle piece!!!!!

Ex. Of Temperature’s Effect on Enzymes Why is having a high fever a problem? Enzymes work best in a small temperature range around the organism’s body temperature (98.6°) Changes in temperature affect the shape and function of an enzyme

The lock-and-key model helps illustrate how enzymes function. If an enzymes structure (shape) changes, it may not work at all (think: puzzle pieces) Substrates bind to an enzyme at certain places called active sites. The enzyme brings substrates together and weakens their bonds. The catalyzed reaction forms a product that is released from the enzyme.

Enzyme Video

Ch. 2 Quiz on Monday 9/8 Notebook Check on Wed 9/10 Classwork/Homework Read about Enzymes Answer questions 1-4 on the bottom of the reading Ch. 2 Quiz on Monday 9/8 Notebook Check on Wed 9/10

The maltase enzyme is perfectly shaped to accept a maltose molecule The maltose binds to the enzyme at the activation point 2 glucose molecules are released The lactase enzyme accepts a lactose molecule The lactose binds to the enzyme at the activation point Glucose molecules are released If a person is lactose intolerant, the body cannot digest food or drinks with lactose

Enzymes in Snake Venom

How might putting ice on a snake bite slow down the destructive enzymes in the snake venom? Changes in temperature affect the shape and function of an enzyme!!!!! By putting ice on a snake bite, until help arrives, you may slow down the enzymes in the snake venom from doing too much damage to your cells

Hemotoxins (bottom of pg. 16) Hemotoxins are toxins that destroy red blood cells, disrupt blood clotting, and/or cause organ degeneration and generalized tissue damage. Injury from a hemotoxic agent is often very painful and can cause permanent damage and in severe cases death. Loss of an affected limb is possible even with prompt treatment. The process by which a hemotoxin causes death is much slower than that of a neurotoxin Snakes which envenomate a prey animal may have to track the prey as it flees. Typically, a mammalian prey will stop fleeing not because of death, but due to shock caused by the venomous bite. Dependent upon species, size, location of bite and the amount of venom injected, symptoms in humans such as nausea, disorientation, and headache may be delayed for several hours.

Neurotoxins (bottom of pg. 16) Neurotoxins can adversely affect function in both developing and mature nervous tissue Neurotoxin activity can be characterized by the ability to inhibit neuron control over ion concentrations across the cell membrane, or communication between neurons across a synapse Macroscopic manifestations of neurotoxin exposure can include widespread central nervous system damage such as intellectual disability, persistent memory impairments, epilepsy, and dementia Additionally, neurotoxin-mediated peripheral nervous system damage such as neuropathy (signals don’t make it through) or myopathy (muscle fibers do not work) is common.

Snake Venom Enzymes and their Reactions Reading ON Enzyme Handout Snake Venom Enzymes and their Reactions Reading Explain how the enzymes in snake venoms can lead to death. What would happen to a person bit by a snake whose venom contains the enzyme “cholinesterase”? Create your own snake venom. Choose 6 of the enzymes listed. In your own words, describe each enzyme’s effect on prey

Snake Venom: Black Mamba Video (15 mins) ON Enzyme Handout Snake Venom Videos Snake Venom and Human Blood Video (2mins) 4. Predict what would happen to a person bitten by a snake whose venom contained hemotoxic properties. 5. Africa’s Black Mamba has neurotoxic venom. Explain what would happen to you if you were bitten by a Black Mamba. Snake Venom: Black Mamba Video (15 mins)