Transcript Proteins
Proteins Regents Biology Proteins: Multipurpose molecules Regents Biology 2006-2007 Proteins Examples muscle skin, hair, fingernails, claws collagen, keratin insulin pepsin pepsin digestive enzyme in stomach insulin hormone that controls blood sugar levels Regents Biology collagen (skin) Proteins Function: many, many functions hormones signals from one body system to another insulin movement muscle immune system protect against germs enzymes Regents Biology help chemical reactions Proteins Building block = amino acids amino amino amino amino amino acid – acid – acid – acid – acid 20 different amino acids H O H | || —N— —C—C—OH | H Regents Biology R Amino acids: An amino group (NH2) An acid group (COOH) A Hydrogen atom And an “R” group Amino acid chains Proteins amino acids chained into a polymer amino acid amino acid amino acid amino acid amino acid Each amino acid is different some “like” water & dissolve in it some “fear” water & separate from it Regents Biology Water-fearing amino acids Hydrophobic “water fearing” amino acids try to get away from water in cell the protein folds Regents Biology Water-loving amino acids Hydrophillic “water loving” amino acids try to stay in water in cell the protein folds Regents Biology For proteins: SHAPE matters! Proteins fold & twist into 3-D shape that’s what happens in the cell! Different shapes = different jobs growth hormone Regents Biology hemoglobin pepsin collagen 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 = “denature” temperature unfolded “denatured” pH (acidity) In Biology, it’s not the size, it’s the SHAPE that matters! Regents Biology folded Let’s EAT some Proteins! Regents Biology 2006-2007 Activities demo raw egg vs. cooked egg drop raw egg into boiling water, like egg drop soup compare raw egg to hard-boiled egg demo cheese-making with heated milk & vinegar make yogurt Regents Biology