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Proteins. Proteins:. Multipurpose molecules. insulin. pepsin. collagen (skin). Proteins. Examples muscle skin, hair, fingernails, claws collagen, keratin pepsin digestive enzyme in stomach insulin hormone that controls blood sugar levels. Proteins. Function:
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Proteins: Multipurpose molecules
insulin pepsin collagen (skin) Proteins Examples • muscle • skin, hair, fingernails, claws • collagen, keratin • pepsin • digestive enzyme in stomach • insulin • hormone that controls blood sugar levels
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
H | —C— | H amino acid amino acid amino acid amino acid amino acid – – – – C—OH —N— O || H Proteins • Building block = amino acids • 20 different amino acids There’s20 of us… like 20 differentletters in analphabet!Can make lots of differentwords variable group
amino acid amino acid amino acid amino acid amino acid 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
Water-fearing amino acids • Hydrophobic • “water fearing” amino acids • try to get away from water in cell • the protein folds
Water-loving amino acids • Hydrophillic • “water loving” amino acids • try to stay in water in cell • the protein folds
Ex)collagen For proteins: SHAPE matters! • Proteins fold & twist into 3-D shape • that’s what happens in the cell! • Different shapes = different jobs **Fibrous** ***Globular*** Examples: growthhormone hemoglobin pepsin
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) unfolded“denatured” In Biology, it’s not the size, it’s the SHAPEthat matters! folded
Let’s EAT some Proteins!
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