_________________________ Proteins: _________________________ 2006-2007

Proteins Examples ______________________ collagen, keratin insulin digestive enzyme in stomach hormone that controls blood sugar levels pepsin collagen (skin)

Proteins Function: many, many functions ________________________ signals from one body system to another insulin muscle protect against germs help chemical reactions

Proteins —N— H | —C— C—OH || O Building block = __________________ – amino acid – ________________________ There’s 20 of us… like 20 different letters in an alphabet! Can make lots of different words —N— H | —C— C—OH || O variable group

Amino acid chains Proteins Each amino acid is different amino acids chained into a polymer amino acid Each amino acid is different __________________________________

Water-fearing amino acids Hydrophobic __________________________________ try to get away from water in cell the protein folds

Water-loving amino acids Hydrophillic __________________________________ try to stay in water in cell the protein folds

For proteins: SHAPE matters! ___________________________________ that’s what happens in the cell! It’s a helix or B sheet within a single region. Can have both in one protein but a specific region is one or another growth hormone hemoglobin pepsin collagen

It’s SHAPE that matters! __________________________________ __________________________________ Unfolding a protein destroys its shape wrong shape = _____________________ unfolding proteins = ________________ temperature pH (acidity) unfolded “denatured” folded