Notes Amino Acids and Proteins

Notes Amino Acids and Proteins - Notes Amino Acids and...

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Notes Amino Acids and Proteins Proteins are about 50% of the dry weight of most cells, and are the most structurally complex molecules known. Each type of protein has its own unique structure and function. Polymers are any kind of large molecules made of repeating identical or similar subunits called monomers. The starch and cellulose we previously discussed are polymers of glucose, which in that case, is the monomer. Proteins are polymers of about 20 amino acids monomers. The amino acids all have both a single and triple letter abbreviation. Here is an example. Alanine = A = Ala Each amino acid contains an "amine" group, (NH 2 ) and a "carboxylic acid" group (COOH) (shown in black in the diagram). The amino acids vary in their side chains (indicated in blue in the diagram). The eight amino acids in the orange area are nonpolar and hydrophobic. The other amino acids are polar and hydrophilic ("water loving"). The two amino acids in the magenta box are acidic ("carboxylic" group in the side chain). The three amino acids in the light blue box are basic ("amine" group in the side chain).
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Amino Acids: shown in another structural formula format C C NH 2 H O OH CH 3 C C NH 2 H O OH CH H 3 C CH 3 C C NH 2 H O OH CH 2 CH H 3 C CH 3 C C NH 2 H O OH CH CH 2 CH 3 CH 3 C C NH H O OH CH 2 CH 2 CH 2 alanine valine leucine isoleucine proline ala – A val – V leu – L ile – I pro – P C C NH 2 H O OH CH 2 C C NH 2 H O OH CH 2 CH 2 S CH 3 C C NH 2 H O OH CH 2 NH * C C NH 2 H O OH H C C NH 2 H O OH CH 2 OH phenylalanine methionine tryptophan glycine * serine phe – F met – M trp – W gly – G ser – S C C NH 2 H O OH CH CH 3 OH C C NH 2 H O OH CH 2 OH C C NH 2 H O OH CH 2 SH C C NH 2 H O OH CH 2 C O NH 2 C C NH 2 H O OH CH 2 CH 2 C O NH 2 threonine tyrosine cysteine asparagine glutamine thr – T tyr – Y cys – C asn – N gln – Q C C NH 2 H O OH CH 2 C O OH C C NH 2 H O OH CH 2 CH 2 C O OH C C NH 2 H O OH CH 2 N NH C C NH 2 H O OH CH 2 CH 2 CH 2 CH 2 NH 2 C C NH 2 H O OH CH 2 CH 2 CH 2 NH C NH 2 NH aspartic acid glutamic acid histidine lysine arginine asp – D glu – E his – H lys – K arg – R
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Amino acids are named as such because each amino acid consists of an amine portion and a carboxylic acid part, as seen below. C C NH 2 H O OH R Compare this structure to the above structures of each of the amino acids. Each amino acid has this general structure. The side chains are sometime shown as R-groups when illustrating the backbone. In the approximately 20 amino acids found in our bodies, what varies is the side chain. Some side chains are hydrophilic while others are hydrophobic. Since these side chains stick out from the backbone of the molecule, they help determine the properties of the protein made from them. The amino acids in our bodies are referred to as alpha amino acids.
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Notes Amino Acids and Proteins - Notes Amino Acids and...

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