regents biology 2009-2010 enzymes: “helper” protein molecules

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Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

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Page 1: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology 2009-2010

Enzymes:

“Helper” Protein molecules

Page 2: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Flow of energy through life Life is built on chemical reactions

Page 3: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Enzyme vocabulary Enzyme

helper protein molecule Catalyst

Speeds up chemical reactions Substrate

molecule that enzymes work on Products

what the enzyme helps produce from the reaction

Page 4: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Enzyme vocabulary Activation Energy

Energy needed to get a reaction started Active site

part of enzyme that substrate molecule fits into

Page 5: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Chemical reactions of life Processes of life

building molecules synthesis

breaking down molecules digestion

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Page 6: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Nothing works without enzymes! How important are enzymes?

all chemical reactions in living organisms require enzymes to work building molecules

synthesis enzymes

breaking down molecules digestive enzymes

enzymes speed up reactions “catalysts”

+

+

enzyme

enzymeWe can’t live

without enzymes!

Page 7: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Examples synthesis

digestion

+

+

enzyme

enzyme

Page 8: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Enzymes are proteins Each enzyme is the specific helper to

a specific reaction each enzyme needs to be the right shape

for the job enzymes are named for the reaction

they help sucrase breaks down sucrose proteases breakdown proteins lipases breakdown lipids DNA polymerase builds DNA

Oh, I get it!They end

in -ase

Page 9: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Enzymes aren’t used up Enzymes are not changed by the reaction

used only temporarily re-used again for the same reaction with

other molecules very little enzyme needed to help in many

reactions

enzyme

substrate product

active site

Page 10: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

It’s shape that matters! Lock & Key model

shape of protein allows enzyme & substrate to fit

specific enzyme for each specific reaction

Page 11: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

1

2

3

Page 12: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

What affects enzyme action Correct protein structure

correct order of amino acids why? enzyme has to be right shape

Temperature why? enzyme has to be right shape

pH (acids & bases) why? enzyme has to be right shape

Page 13: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Order of amino acids Wrong order = wrong shape = can’t do its job!

DNA

DNA

chain ofamino acids

chain ofamino acids

foldedprotein

foldedprotein

right shape!

wrong shape!

Page 14: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

Temperature Effect on rates of enzyme activity

Optimum temperature greatest number of collisions between

enzyme & substrate human enzymes

35°- 40°C (body temp = 37°C) Raise temperature (boiling)

denature protein = unfold = lose shape Lower temperature T°

molecules move slower fewer collisions between enzyme &

substrate

Page 15: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

37°

Temperature

temperature

reac

tio

n r

ate

What’s happening here?!

humanenzymes

Page 16: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

How do cold-blooded creatures do it?

Page 17: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

pH Effect on rates of enzyme activity

changes in pH changes protein shape most human enzymes = pH 6-8

depends on where in body pepsin (stomach) = pH 3 trypsin (small intestines) = pH 8

Page 18: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology

7

pH

pH

reac

tio

n r

ate

20 1 3 4 5 6 8 9 10

stomachpepsin

intestinestrypsin

What’s happening here?!

11 12 13 14

Page 19: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology 2009-2010

For enzymes…What matters?

SHAPE!

Page 20: Regents Biology 2009-2010 Enzymes: “Helper” Protein molecules

Regents Biology 2009-2010

Let’s build some

Enzyme Models!