enzymes. learning target: 1. recognize enzymes as catalysts: a. protein molecules that function to...
TRANSCRIPT
Enzymes
Enzymes Learning Target:
1. Recognize enzymes as catalysts:a. Protein molecules that function to lower
activation energy (increase rate of a reaction)
b. Reusable and specific in function
c. Altered by high temperature, pH, and metals (lead, mercury)
2. Recognize how the enzyme-substrate complex model demonstrates the function of enzymes.
Enzymes Objectives continued:3. Recognize a reason why an enzymes
ability to lower activation energy would be beneficial to a living organism
4. Be able to collect, graph, and analyze data relating to enzymes reactions.
5. Explain catalase enzyme action based on the class demo.
Enzymes
A protein that speeds up a chemical reaction
Biological Catalyst
Recall:Inorganic Chemistry
Reactants Catalyst→ ProductsOrganic Chemistry
Substrate Enzyme→ Products
Enzymes activation energy
Energy needed to start a reaction
Enzymes lower the amount of activation energy needed to start a reaction
Enzyme Functions Involved in nearly all metabolic processes.
Speeds up the reactions in digestion of food synthesis of molecules - storage of energy release of energy (aids in breaking molecules into
monomers) Used in transmission of nerve impulses muscle contraction cellular energy
Enzyme Characteristics
Remains unchanged in a reaction Never used up Each enzyme has a specific job
Ex. Amylase – starch enzyme Lactase – lactose enzyme Catalase – hydrogen peroxide enzyme(byproduct
of cell metabolism-poisonous if can’t break down) Sucrase – sucrose enzyme
Enzymes Terms: Substrate – The molecule(s)
that the enzyme acts upon Active Site – the location on
the enzyme where the substrate binds
Theories: Lock and Key theory- specific fit
between the substrate and enzyme
Induced Fit Model- enzyme changes shape a little to fit with the substrate “molds to fit”
Enzymes
Enzymes Coenzyme – a helper, such as vitamins Inhibitor – molecule that blocks or
changes the active site so the substrate cannot bind (2 Types)
Reversible:
Competitive Inhibitors – attaches to active site … competes with substrate for site
1. inhibitor is chemically similar to the substrate
2. Temporary attachment (doesn’t alter active site)
Non-Competitive Inhibitors – binds with the enzyme at a location
other than the active site, altering the shape of the active site
Enzymes
Types of Inhibitors continued Irreversible
Permanently inactivates the enzyme Ex. Poison, exposure to heavy metals such as
mercury and lead
Denaturation – active site of the enzyme is altered,
Causes: temperature, heavy metals, pH
Enzyme review and Negative Feedback
Factors that affect Enzyme Activity pH Temperature Concentration of an enzyme Concentration of substrate Amount of surface area
Enzyme Use Examples: Cheese makers use RENIN (enzyme) to
curdle milk Some laundry detergents contain enzymes
to get rid of soiled spots on clothing Contact Cleaner