Enzymes Biology Mrs. Hunt

ENZYMES end in “ASE” ENZYME: a CATALYST, usually a protein, in living systems CATALYST: a substance that SPEEDS UP a chemical reaction WITHOUT being chemically CHANGED by the reaction Our bodies use catalyst called enzymes to BREAK DOWN FOOD and CONVERT it into ENERGY (ATP!!)

Enzymes are necessary for all biochemical reactions Biological reactions Ex: METABOLISM - would eventually take place on their own, but the presence of enzymes enable reactions to take place about a MILLION times faster! Some enzyme failures result in DISEASE or DEATH of the organism!

Enzymes are SPECIFIC. Some control only a single chemical reaction while others control broader SPECIFICITY. LACTASE - LACTOSE MALTASE – MALTOSE CELLULASE - CELLULOSE Enzymes are REUSABLE.

FACTORS affecting ENYZMES… Cause them to DENATURE!! TEMPERATURE pH AMOUNT OF SUBSTRATE pH: numerical range that quantifies the relative concentration of hydronium ions and hydroxide ions in a solution. Ranges from 0-14 & may be acidic, neutral, or basic.\ Most enzymes have OPTIMUM pH between 6 and 8. Some bacteria have enzymes that have an optimum temp. at 70°C or higher, this would destroy most human enzymes!

1 - 6  ACIDIC 7  NEUTRAL 8 – 14  BASIC pH SCALE 1 – 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 - 6  ACIDIC 7  NEUTRAL 8 – 14  BASIC

How do they work? Enzyme reactions depend on a PHYSICAL fit BETWEEN the ENZYME and its SUBSTRATE (reactant being catalyzed) ENZYME and SUBSTRATE have SPECIFIC SHAPES that allow them to FIT TOGETHER like a LOCK & KEY (there is 1 enzyme for 1 substrate) When linkage occurs, enzyme changes slight shape – ENZYME IS UNCHANGED After reaction, ENZYME RELEASES PRODUCTS (enzyme unchanged!) Animation: How Enzymes Work