Biology I Proteins
Regents Biology Proteins: Multipurpose molecules
Biology I collagen (skin) Proteins insulin Examples muscle skin, hair, fingernails, claws collagen, keratin pepsin digestive enzyme in stomach insulin hormone that controls blood sugar levels pepsin
Biology I Proteins Function: many, many functions hormones signals from one body system to another insulin movement muscle immune system protect against germs enzymes help chemical reactions
Biology I Proteins Building block = amino acid amino acid – amino acid – amino acid – amino acid – —N——N— H H H | —C— | C—OH || O variable group amino acids 20 different amino acids There’s 20 of us… like 20 different letters in an alphabet! Can make lots of different words
Biology I Amino acid chains Proteins amino acids chained into a polymer Each amino acid is different some “like” water & dissolve in it some “fear” water & separate from it amino acid
Biology I Water-fearing amino acids Hydrophobic “water fearing” amino acids try to get away from water in cell the protein folds
Biology I Water-loving amino acids Hydrophillic “water loving” amino acids try to stay in water in cell the protein folds
Biology I pepsin For proteins: SHAPE matters! collagen Proteins fold & twist into 3-D shape that’s what happens in the cell! Different shapes = different jobs hemoglobin growth hormone
Biology I 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 pH (acidity) folded unfolded “denatured” In Biology it’s the SHAPE that matters!
Biology I Let’s EAT some Proteins!
Biology I 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