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37 Cards in this Set
- Front
- Back
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What is Hemoglobin?
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(a protein) transport O2 and Co2 in blood
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What is Keratin?
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(a protein) is used for nails, hair, and horns of rhino
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Describe Proline.
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cyclic AA which is different from being an aromatic AA which has a cylic R group
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What are the building blocks proteins?
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AA’s are building blocks of proteins
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Which stereoisomeric form of AA's do humans/animals use?
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Humans and animal uses L forms.
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Which AA doesn't have a stereoisomer and why>
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Glycine doesn’t have a stereoisomer because it is not chiral it has 2 H.
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What are the Five groups of amino acids?
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nonpolar, aromatic, pilar, + charged, -charged.
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Which AA's can absorb ultraviolent light?
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Aromatic AA’s Tyrosine and Tryptophan absorb ultraviolent light
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Describe lysine.
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Positively charged amino acid lysine (note positive charge on side chain nitrogen), used by proteins to interact with other proteins, DNA/RNA, and drugs.
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NONPOLAR AA.
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(7)
G= Glycine A= Alanine Va= Valine L= Leucine I= Isoleucine M= Methionine P= Proline |
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Describe Phenylketonuria (PKU?
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genetic disorder characterized by a deficiency in the hepatic enzyme phenylalanine hydroxylase which is necessary to metabolize the amino acid phenylalanine to the amino acid tyrosine.
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AROMATIC AA
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(3) phenylalanine, tryptophan, and tyrosine. Have ring R group.
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Polar AA
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(5) Serine, Threonine, Cystein, Asparagine, Glutamine. Have O in R group. Cystein has SH in R group.
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+ charged
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(3) Lysine, Arginine, Histidine
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Why isnt Histidine shown as + charged?
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Small but significant fraction of Histidines are positively charged at pH 7.0.
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- Charged
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(2) Aspartate (aspartic acid) and Glutamate (Glutamic acid).
-have coo- in R group |
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Which group of AA Absorb of ultraviolet light?
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aromatic amino acids
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Which aromatic AA absorbs light the best?
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tryptophan is as much as four times that of tyrosine.
phenylalanine contributes little |
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Which AA forms a disulfide bond?
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Reversible formation of a disulfide bond by the oxidation of two molecules of cysteine.
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Disulfide bonds between Cys stabilize the structures of _____?
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Disulfide bonds between Cys residues stabilize the structures of many proteins including insulin.
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What are the 2 uncommon amino acids that are used in collagen?
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4-hydroxyproline, 5-hydroxylysine
-derived from common aa. |
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Amino acids modified by _____ &_____?
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Amino acids modified by phosphorylation and adenylation.
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What is Adenylation?
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Adenylation is the covalent attachment of an adenylate (adenosine 5’-monophosphate, a ribonucleotide) to another molecule.
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What is a zwitterion?
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A zwitterion can act as either an acid (proton donor) or a base (proton acceptor).
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All free amino acids are what?
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All free amino acids are at least diprotic acids (i.e., buffers)
because they can either release, or bind, 2 hydrogens. |
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What is pI on a titration curve?
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isoelectric point,
the pH at which the aa has no net charge |
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_____ is the only amino acid that has buffering capacity around pH 7.4, the pH of blood?
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histidine is the only amino acid that has buffering capacity around pH 7.4, the pH of blood
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How are peptide bonds formed?
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Condensation
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What is a warning to Phenylketonurics?
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Aspartame is broken down during digestion into Aspartate and Phenylalanine.
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A protein’s amino acid composition is responsible for?
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its structure, function, and pI.
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Special note for Histidine?
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+ charge gives a STRONG H bond (closer to ionic bond).
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CH3 groups on nonpolar AA's are proton donors or proton acceptors?
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NEITHER.
CH3 group is not a proton donor or acceptor= very hydrophobic. |
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How are disulfide bonds special covalent bonds?
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Disulfide bond is an easily reversible covalent bond which is unusual for covalent bonds
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How can an AA act as an acid?
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amine group releases H (acid)
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How can an AA act as a base?
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carboxyl group picks up H (base)
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What is a clinical use of a spectrophotometer?
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Measure the protein/drug concentration of a solution.
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What two AA's contain sulfur?
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Cystein or di-aminoacid Cystine and Methionine
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