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Proteins

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

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  1. Proteins

  2. Proteins: Multipurpose molecules

  3. 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

  4. Proteins • Function: • many, many functions • hormones • signals from one body system to another • insulin • movement • muscle • immune system • protect against germs • enzymes • Help speed up chemical reactions

  5. 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

  6. 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

  7. Water-fearing amino acids • Hydrophobic • “water fearing” amino acids • try to get away from water in cell • the protein folds

  8. Water-loving amino acids • Hydrophillic • “water loving” amino acids • try to stay in water in cell • the protein folds

  9. collagen For proteins: SHAPE matters! • Proteins fold & twist into 3-D shape • that’s what happens in the cell! • Different shapes = different jobs growthhormone hemoglobin pepsin

  10. Protein Structures • Primary Structures – it’s the amino acid sequence • Determined by the genetic code in the mRNA. • It is produced in the ribosome.

  11. Protein Structures • Secondary Structures – form as a result from hydrogen bonds between peptide groups. • Planar or cylindrical

  12. Protein Structures • Tertiary Structures – Its 3 dimensional formation as a result of protein folding. • Happens because of bonds between R groups of different amino acids.

  13. Protein Structures • Quaternary Structures – 2 or more polypeptide chains associate and form a single protein. • Hemoglobin are 4 different amino acid chains.

  14. 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

  15. Enzymes • Catalyst –speeds up the rate of a chemical reaction • Enzymes – proteins that act as biological catalysts • Enzymes help lower the activation energy of a chemical reaction • the energy needed to get a reaction started

  16. Enzymes • Substrates bind to a site on the enzyme called the active site SHAPE MATTERS!!

  17. Enzymes – Usually end in -ase Enzyme Substrate Lactase Lactose Amylase Carbohydrate Sucrase Sucrose Maltase Maltose

  18. ______________ ___________ ___________ ___________ Substrate Products Active Site Enzyme

  19. Enzymes • The fit between the active site and substrates is so precise that it is often compared to a lock and key

  20. Factors that affect enzyme activity • Temperature • Concentration • pH FGHGFH CONCENTRATION LOW CONCENTRATION

  21. Let’s EAT some Proteins!

  22. 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

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