Enzymes: "Helper" Protein molecules

Warm Up Base your answer to this question on the diagram below, which represents stages in the digestion of a starch, and on your knowledge of biology. The products would most likely contain A. simple sugars. C. amino acids. B. fats. D. minerals. Regents Biology Enzymes: Helper Protein molecules Regents Biology

2009-2010 Chemical Reactions A. When bonds are broken and reformed to make different substances. EX: Reactants Products C6H12O6 + 6O2 6CO2 + 6H2O Regents Biology Chemical reactions of life

Processes of life A. building molecules = synthesis + B. breaking down molecules = digestion + Regents Biology Energy released Energy absorbed What is needed to start a reaction?

Regents Biology Activation energy Reactant Products Nothing works without enzymes! How important are enzymes? A. all chemical reactions in living organisms require enzymes to work building molecules = synthesis enzymes enzyme +

We cant live without enzymes! breaking down molecules = digestive enzymes enzyme + Regents Biology B. enzymes speed up reactions = catalysts Regents Biology C. Digestion Reaction

Is the breakdown of a complex molecule into simpler substances These reactions RELEASE energy Enzyme Regents Biology Enzyme Enzyme Enzyme

D. Synthesis Reaction The combining of simple molecules into a more complex ones This reaction builds new molecules and/or STORES energy Reactants Products Enzyme Regents Biology

Enzyme Enzyme Examples Synthesis + enzyme Digestion enzyme Regents Biology +

Enzymes are proteins & each enzyme is the specific helper to a specific reaction. A. Each enzyme needs to be the right shape for the job B. Enzymes are named for the reaction they help i. sucrase breaks down sucrose ii. proteases breakdown proteins iii. lipases breakdown lipids Oh, I get it! They endiv. DNA polymerase builds DNA in -ase Regents Biology Enzymes arent used up

**Enzymes are NOT changed by the reaction A. used only temporarily B. re-used again for the same reaction with other molecules C. very little enzyme needed to help in many reactions substrate active site Regents Biology product enzyme Its shape that matters! Lock & Key Theory

A. shape of protein allows enzyme & substrate to fit B. specific enzyme for each specific reaction Substrate Enzyme Regents Biology Products What Affects Enzyme Activity Temperature: pH:

Battery Acid Regents Biology 0 Blood (7.5) 3 5 7 Neutral

9 Bleach 11 13 Temperature & Effect on Rates of Enzyme Activity A. Optimum (best) temperature i. greatest number of collisions between enzyme & substrate ii. human enzymes = 35- 40C (body temp = 37C) B. Raise temperature (boiling)

i. denature protein = unfold = lose shape C. Lower temperature i. molecules move slower ii. fewer collisions between enzyme & substrate Regents Biology Temperature Reaction Rate human enzymes 37

Temperature ( C) Regents Biology Whats happenin g here?! pH & Effect on Rates of Enzyme Activity A. changes in pH = changes protein shape B. most human enzymes work best at pH 6-8 i. depends on where in body ii. pepsin (stomach) = pH 3 iii. trypsin (small intestines) = pH 8 Regents Biology

pH stomach pepsin Whats happenin g here?! reaction rate intestines trypsin 0

1 2 3 4 5 6 7

pH Regents Biology 8 9 10 11 12 13 14 Denature A. When enzymes are exposed to extreme pH or high temperatures, they can denature B. When denatured, an enzyme will no longer function, due to a change in enzyme structure C. This is why running high fevers for extended time is cause for concern

Regents Biology Enzyme vocabulary review Enzyme Protein; speeds up chemical reactions by lowering activation energy Substrate molecule that enzymes work on

Products what the enzyme helps produce from the reaction Active site part of enzyme that substrate molecule fits into Regents Biology