Regents Biology 2006-2007

Proteins: The Multipurpose Molecules

Regents Biology

Protein Functions enzymes structure transport cell to cell signals defense (antibodies) movement storage

Regents Biology collagen

Protein Examples: Keratin

hair and nail

collagen protein in skin

pepsin digestive enzyme

in stomach

insulin hormone that controls blood sugar

levels

pepsin insulin

Regents Biology

Protein Monomers = amino acids Structure

central carbon amino group carboxyl group (acid) R group (side chain)

variable group 20 different amino acids

—N—H

HC—OH

||O

R

|—C—

|

H

Oh, I get it!amino = NH2 acid = COOH

Regents Biology

Monomer to Polymer = amino acid chains

Proteins are amino acids chained into a polymer (called a polypeptide)

Each amino acid is different Example some “like” water & dissolve in it

Example some “fear” water & separate from it

amino acid amino acid amino acid amino acid amino acid

Regents Biology

Regents Biology pepsin

For proteins: SHAPE matters!

collagen

Proteins fold & twist into 3-D shape Different shapes = different jobs

hemoglobingrowth

hormone

Regents Biology

It’s SHAPE that matters! Proteins do their jobs, because of their shape Unfolding a protein destroys its shape

wrong shape = can’t do its job unfolding proteins called “denaturization”

temperature pH (acidity) salt

folded

unfolded“denatured”

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

Regents Biology

Any questions?

Yea…what’s upwith that coat?

Looks like my cousin