Proteins Regents Biology Proteins Multipurpose molecules Regents Biology

Proteins Regents Biology

Proteins: Multipurpose molecules Regents Biology 2006 -2007

Proteins Examples u muscle u skin, hair, fingernails, claws § collagen, keratin u insulin pepsin § digestive enzyme in stomach u insulin § hormone that controls blood sugar levels collagen (skin) Regents Biology

Proteins § Function: u many, many functions § hormones w signals from one body system to another w insulin § movement w muscle § immune system w protect against germs § enzymes Regents Biology w Help speed up chemical reactions

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

Amino acid chains § Proteins u amino acids chained into a polymer amino acid amino acid § Each amino acid is different u some “like” water & dissolve in it u some “fear” water & separate from it Regents Biology

Water-fearing amino acids § Hydrophobic “water fearing” amino acids u try to get away from water in cell u § the protein folds Regents Biology

Water-loving amino acids § Hydrophillic “water loving” amino acids u try to stay in water in cell u § the protein folds Regents Biology

For proteins: SHAPE matters! § Proteins fold & twist into 3 -D shape u that’s what happens in the cell! § Different shapes = different jobs growth hormone Regents Biology hemoglobin pepsin collagen

Protein Structures § Primary Structures – it’s the amino acid sequence Determined by the genetic code in the m. RNA. u It is produced in the ribosome. u Regents Biology

Protein Structures § Secondary Structures – form as a result § from hydrogen bonds between peptide groups. Planar or cylindrical Regents Biology

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

Protein Structures § Quaternary Structures – 2 or more polypeptide chains associate and form a single protein. u Hemoglobin are 4 different amino acid chains. Regents Biology

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 u unfolding proteins = “denature” u § temperature § p. H (acidity) In Biology, it’s not the size, it’s the SHAPE that matters! Regents Biology unfolded “denatured” folded

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 u the energy needed to get a reaction started Regents Biology

Regents Biology

Enzymes § Substrates bind to a site on the enzyme called the active site SHAPE MATTERS!! Regents Biology

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

Substrate ______ Active Site _______ Enzyme Regents Biology ______ Products

Enzymes § The fit between the active site and substrates is so precise that it is often compared to a lock and key Regents Biology

Factors that affect enzyme activity §Temperature §Concentration FGHGFH CONCENTRAT ION §p. H Regents Biology LOW CONCENTRAT ION

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 u compare raw egg to hard-boiled egg u § demo cheese-making with heated milk § & vinegar make yogurt Regents Biology