問題一覧
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Building blocks/stones of proteins Fundamental sub-units of proteins
amino acid
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GENERAL FORMULA:
Carboxyl group = acidic properties Amino group= basic properties Chiral C= asymmetric carbon
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CHARACTERISTICS
1. Optically active All amino acids are optically active except glycine( its side chain is a hydrogen ato 2. amphoteric can act as an acid (proton donor) & as a base (proton acceptor ) 3.Zwitterion Possesses both a positive or negative ion Acidity is due to П electron delocalization. 4.Isoelectric Point (pl) The pH value at which zwitterion state exists at a maximum 5. ACID-BASE PROPERTY
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plane polarized light shifted to the right
1.a. dextrorotatory (+)
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plane polarized light shiftedto the left
1.b. levorotatory
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IMPORTANCE OF pl:
1. Used in buffer systems 2. For separation & identification purposes - since each amino acid has its distinct pl 3. Show structural changes in globular CHON- the explanation of structures of biological reactions
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All amino acids are optically active except nycin (its side chain is a hydrogen atom) Due to the presence of chiral asymmetric carbon Ability to rotate the plane polarized light in a polarimeter
optically active
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(+) plane polarized light shifted to the right
dextrorotatory
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(+)-plane colanzed light shifted to the left
levoratatory
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Can act as an acid (protan donor) & as a base (proton acceptor
amphoterix
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COOH
proton donor
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NH2 -proton acceptor (base
proton acceptor (base
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Possesses both a positive or negative ion Acidity is due to n electron delocalization. The OH bond in COOH weakens so it is readily easily given off. or lost as a proton and is accepted by the lone pair in NH3
zwitterion
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The pH value at which zwittenon state exists at a maximum Amino acids & proteins assume a zero net charge Amino acids & proteins are least soluble (ppt form) No integration in an electric field
isolectric point
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NEUTRAL OR STRAIGHT CHAIN AMINO ACIDS: (POLAR)
glycine alanine
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Those which cannot be synthesized in the body Must be provided in the diet Primarily concerned with growth and maintenance of life
essential acids
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Growing children require them in food But they are not essential for the adult individual
partially essential amino acid
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Those which can be produced in the body
non essential/ dispensable amino acid
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When a person is suffering from a moderate to severe chronic Glycine liness, person may lose the ability to manufacture enough non- essential amino acids and thus require supplementation Problems with digestion will also necessitate supplementation of "non-essential" amino acids. These amino acids are normally non-essential, but become essential during times of physiological stress Then these amino acids have to be taken in food or through supplements
conditionally amino acid
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according to metabolism
a. purely ketogenjc b. ketogenic and glucogenic c. purely glucogenic
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because it is converted to ketone bodies
purely ketogenic
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are partially ketogenic and partially-glucogenic During metabolism, part of the carbon skeleton of these amino acids will enter the ketogenic pathway and the other part to glucogenic pathway
ketogenic and glucogenic
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are purely glucogenic as they enter only into the glucogenic pathway which provide a substrate for gluconeogenesis
purely glucogenic
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essential in spermatogenesis
argenine
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has been widely studied for its effect in raising the general intelligence level of subnormal patient Used for the treatment of psychomotor and petit mal attacks
glutamic acid
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Simplest amino acid and has is sweet in taste
glysine
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(IAA) GABA glycine, B-alanine, Taurine
Inhibitory amino acid neurotransmitters
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L-glutamate, L-Aspartate, L-cysteine, and L-Homocysteine
Excitatory amino acid neurotransmitters
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Came from the Greek word "PROTEIOS meaning "pre-eminence or of first importance Most important macromolecule Organic compounds of high molecular weight (macromolecular made up of many amino acids)means of peptide linkages. Peptide bond is a covalent bond and can be dipeptide tripeptide, tetrapeptide, and oligopeptide Made up of C, H, O, N, usually S and traces of Fe, Cu, I. Mn, Zn etc Litmus paper red-blue
protein