Download Enzymes

ENZYMES
ENZYMES AND CHEMICAL REACTIONS
 Chemical reactions must occur continuously in living things!
 Examples:
REACTANTS
• Photosynthesis
• Breaking down food
 Can occur with the help of
macromolecules called
ENZYMES
ENZYMES.
Enzyme names usually end in -ASE
PRODUCTS
WHAT ARE ENZYMES?
Enzymes belong to the biomolecule group of
PROTEINS
ENZYMES ARE PROTEINS …
CONTAIN
NITROGEN
MADE OF AMINO
ACID
MONOMERS
PEPTIDE
BONDS
FUNCTION OF ENZYMES
 Enzymes are proteins that function as
CATALYSTS
This means they help to speed up chemical reactions
How? They lower the activation energy of reaction so it
takes LESS energy for the reaction to take place.
Enzymes are very specific and will only catalyze one
specific chemical reaction.
The enzyme wont change after the reaction takes
place, it is recycled!
VS.
FUNCTION OF ENZYMES:
1. Spend one minute writing an explanation of the
FUNCTION of enzymes. YOU MUST USE THE
WORDS CATALYST, ACTIVATION ENERGY,
RECYCLABLE
2. Turn to your neighbor and explain to them!
3. Improve the explanation on your notes and be
prepared to share!
BEEP
BEEP
STRUCTURE OF ENZYMES
Substrate
Active
Site
Enzymes match with
a substrate that fits
like a puzzle at an
active site.
Enzyme
LABEL
YOURS!
STRUCTURE OF ENZYMES
The structure of enzymes and substrates are a “lock and key”
model
The molecules that bind to the enzyme are called substrates.
The location where they bind (sit down) is called the active
site.
1
2
3
• After the enzyme and substrate bind it is called an enzymesubstrate complex.
Ex. DISACCHARIDE TURNS TO MONOSACCHARIDES
STRUCTURE OF ENZYMES:
CAN YOU WRITE AND VERBALLY EXPLAIN
THE STRUCTURE OF ENZYMES?
IF NOT, YOU DON’T KNOW IT
FACTORS THAT AFFECT ENZYME ACTION
1. TEMPERATURE- the rate of an enzyme increases with
temperature.
 If the temperature is too high, it can DENATURE
(destroy) the shape of an enzyme so that it no longer fits
the substrate.
FACTORS THAT AFFECT ENZYME ACTION
2. pH- enzymes work efficiently at a specific pH.
• Enzymes in blood work best at a pH of 7 (neutral)
• Enzymes in stomach work best at a pH of 2 (acid)
• Enzymes in intestine work best at a pH of 8 (base)
FACTORS THAT AFFECT ENZYME ACTION
3. An INHIBITOR may prevent or slow the enzyme rate
by blocking the active site where the substrate sits down!
4. The concentration of ENZYMES OR SUBSTRATES
can also affect the action. More enzyme = more work!
FACTORS THAT AFFECT ENZYME ACTION
List the 5 factors that affect enzyme action in your notes.
1. Temperature
2. pH
3. Hormones
4. Inhibitors
5. Concentration of enzymes and substrates
EXAMPLES OF BIOLOGICAL
ENZYMES
Lipase — breaking down of fats (lipid)
Protease — breaking down of proteins
Cellulase — breaking down of fiber (cellulose)
Amylase — breaking down of starch (amylose)
Lactase — breaking down of dairy products (lactose)
Sucrase — breaking down of sugar (sucrose)
Maltase — breaking down of grains (maltose)