BIO - TERMS - AMINO ACID

Question 1

amino acid activation

Answer 1

ATP-dependent enzymatic esterification of the carboxyl group of an amino acid to the 3’-hydroxyl group of its corresponding tRNA.

Question 2

C-terminal amino acid

Answer 2

The amino acid with a free -CO2H group at the end of a protein chain.

Question 3

chemical score // amino acid score

Answer 3

The amount of a limiting amino acid in a particular protein or diet in relation to the requirement or need by that organism. Also known as amino acid score.

Question 4

N-terminal amino acid

Answer 4

The amino acid with a free -NH2 group at the end of a protein chain.

Question 5

Non-protein amino acid (NPAA)

Answer 5

Secondary metabolite, which is an analogue of a proteinogenic amino acid; if incorporated into proteins, the latter are usually inactivated.

Question 6

Protein amino acid sequence

Answer 6

Encoded in the genome, translated from the nucleobase sequence into the mRNA where a sequence of three bases is encoding one amino acid during subsequent translation at the ribosomes. All proteins are built from 20 natural amino acids linked by peptide bonds; their sequence determines the three-dimensional structure and the functions of a protein.

Question 7

synthesis of amino acids

Answer 7

The process of the production of amino acids by the body from other compounds.

Question 8

α-Amino acid

Answer 8

A type of difunctional compound with an amino group on the carbon atom next to a carboxyl group, RCH(NH2)CO2H.

Question 9

altered peptide ligands (APLs)

Answer 9

Peptides in which amino acid substitutions have been made in T-cell receptor contact positions that affect their binding to the receptor.

Question 10

Amidomalonate synthesis

Answer 10

A method for preparing α-amino acids by alkylation of diethyl amido malonate with an alkyl halide followed by deprotection and decarboxylation.

Question 11

amino-terminal residue

Answer 11

The only amino acid residue in a polypeptide chain with a free α-amino group; defines the amino terminus of the polypeptide.

Question 12

Amphiprotic

Answer 12

Capable of acting either as an acid or as a base. Amino acids are amphiprotic.

Question 13

ATZ Derivative

Answer 13

An anilinothiazolinone, formed from an amino acid during Edman degradation of a peptide.

Question 14

autophosphorylation

Answer 14

Strictly, the phosphorylation of an amino acid residue in a protein that is catalyzed by the same protein molecule; often extended to include phosphorylation of one subunit of a homodimer by the other subunit.

Question 15

Boc derivative

Answer 15

A butyloxycarbonyl N-protected amino acid.

Question 16

capsaicinoid

Answer 16

An amino acid–based nutraceutical found primarily in peppers that can be used in topical ointments and nasal sprays to relieve pain.

Question 17

carboxyl-terminal residue

Answer 17

The only amino acid residue in a polypeptide chain with a free -carboxyl group; defines the carboxyl terminus of the polypeptide.

Question 18

Carboxypeptidases A and B

Answer 18

Two pancreatic carboxypeptidases cleaving hydrophobic and basic amino acids, respectively.

Question 19

Chain-termination codon

Answer 19

A codon that specifies polypeptide chain termination rather than the incorporation of an amino acid. There are three such codons (UAA, UAG, and UGA), and they are recognized by protein release factors rather than tRNAs.

Question 20

Colinearity (adj, colinear)

Answer 20

A relationship in which the units in one molecule occur in the same sequence as the units in another molecule which they specify; for example, the nucleotides in a gene are colinear with the amino acids in the polypeptide encoded by that gene.

Question 21

complete protein

Answer 21

A protein that contains all essential amino acids capable of promoting growth and maintenance. Also known as a high biologic value protein. computerized axial tomography (CAT or CT) scan Sophisticated form of low-intensity x-ray received by a detector across the tissue that produces a “slice” image of the body. Slices can be pieced together using a computer to provide a three-dimensional image.

Question 22

conservative substitution

Answer 22

Replacement of an amino acid residue in a polypeptide by another residue with similar properties; for example, substitution of Glu by Asp.

Question 23

Cystinuria

Answer 23

An inherited defect in the transport of dibasic amino acids in kidney and intestine; causes kidney stones.

Question 24

dipeptide

Answer 24

Two amino acids linked together.

Question 25

ER retention signal

Answer 25

Short amino acid sequence on a protein that prevents it from moving out of the endoplasmic reticulum (ER). Found on proteins that are resident in the ER and function there.

Question 26

Fmoc derivative

Answer 26

A luorenylmethyloxycarbonyl N-protected amino acid.

Question 27

frame shift

Answer 27

A mutation caused by insertion or deletion of one or more paired nucleotides, changing the reading frame of codons during protein synthesis; the polypeptide product has a garbled amino acid sequence beginning at the mutated codon.

Question 28

Fusion peptide

Answer 28

A short hydrophobic amino acid sequence (20 to 30 amino acids) that is thought to insert into target membranes to initiate fusion. (Chapter 5)

Question 29

glucocorticoid receptor

Answer 29

A receptor activated by cortisol released from the adrenal gland. glutamate (Glu) An amino acid; the major excitatory neurotransmitter in the central nervous system.

Question 30

glycine (Gly)

Answer 30

An amino acid; an inhibitory neurotransmitter at some locations in the central nervous system.

Question 31

Hartnup disease

Answer 31

An inherited defect in the renal and intestinal transport of large neutral amino acids, with pellagra-like symptoms.

Question 32

Homocysteine

Answer 32

An amino acid derived from methionine; possible risk factor for atherosclerosis.

Question 33

Homocystinuria

Answer 33

An inborn error in the metabolism of the sulfur amino acids, causing skeletal deformities and mental deficiency.

Question 34

hypermethioninemia

Answer 34

A condition resulting in an increase in the amino acid methionine, accumulating in the blood often due to a defect in the enzyme methionine adenosyl transferase, which converts methionine to S-adenosyl methionine.

Question 35

Intein

Answer 35

A short stretch of amino acids that is excised from a polypeptide.

Question 36

L domain sequence

Answer 36

Short amino acid sequences required for membrane fusion during budding of enveloped viruses. (Chapter 13)

Question 37

malonic acid pathway

Answer 37

A biochemical pathway whereby three molecules of acetyl CoA are biochemically converted into three molecules of malonyl CoA, which are eventually used in the synthesis of flavones, isoflavones, and flavanols from metabolites of the aromatic amino acids phenylalanine, tyrosine, and tryptophan.

Question 38

Multigene family

Answer 38

A group of genes that are similar in nucleotide sequence or that produce polypeptides with similar amino acid sequences.

Question 39

Nitrogen reduction and assimilation

Answer 39

Metabolic reduction of nitrate and its incorporation in amino acids.

Question 40

nitrosamine

Answer 40

A carcinogen formed by the combination of nitrite and amino acids.

Question 41

nonsense suppressor

Answer 41

A mutation, usually in the gene for a tRNA, that causes an amino acid to be inserted into a polypeptide in response to a termination codon.

Question 42

Nonsynonymous substitution

Answer 42

A base-pair change in a codon that alters the amino acid specified by the codon.

Question 43

oligopeptide

Answer 43

A few amino acids joined by peptide bonds.

Question 44

Order (in the genetic code)

Answer 44

There are two types of order in the genetic code: (1) multiple codons for a given amino acid usually differ only at the third position, and (2) the codons for amino acids with similar chemical properties are closely related.

Question 45

Phenylpropanoids

Answer 45

Aromatic heterocycles generated from aromatic amino acids and universally distributed over the plant kingdom. As soluble (usually glycosylated) form in the vacuoles or insolubly incorporated into polymeric structures like lignin suberin or sporopollenin.

Question 46

R group

Answer 46

(1) Formally, an abbreviation denoting any alkyl group. (2) Occasionally, used in a more general sense to denote virtually any organic substituent (the R groups of amino acids, for example).

Question 47

Selenocysteine

Answer 47

An amino acid that contains selenium (atomic number 34) in place of the sulfur group in cysteine.

Question 48

Selenoprotein

Answer 48

A protein that contains the amino acid selenocysteine.

Question 49

sense codon

Answer 49

A codon that codes for an amino acid.

Question 50

sequence motif

Answer 50

A pattern of nucleotides or amino acids shared by different genes or proteins that often have related functions.

Question 51

SILAC

Answer 51

Stable isotope labeling by amino acids in cell culture for protein quantification in mass spectrometry.

Question 52

simple protein

Answer 52

A protein yielding only amino acids on hydrolysis.

Question 53

start-transfer signal

Answer 53

Short amino acid sequence that enables a polypeptide chain to start being translocated across the endoplasmic reticulum membrane through a protein translocator. Multipass membrane proteins sometimes have both N-terminal (signal sequence) and internal start-transfer signals.

Question 54

Structural plasticity

Answer 54

Th e ability of virus particles to tolerate large numbers of amino acid substitutions in surface proteins without losing infectivity. (Chapter 5)

Question 55

Suppressor tRNA

Answer 55

A mutant tRNA that recognizes one or more of the termination codons and inserts an amino acid at a site where translation termination would normally occur.

Question 56

Synonymous substitution

Answer 56

A base-pair change in a codon that does not alter the amino acid specified by the codon.

Question 57

type III fibronectin repeat

Answer 57

The major repeat domain in fibronectin, it is about 90 amino acids long and occurs at least 15 times in each subunit. The repeat is among the most common of all protein domains in vertebrates.

Question 58

tyrosine

Answer 58

A non-essential amino acid involved with protein synthesis and an intermediate in the production of acetyl CoA and neurotransmitters.

Question 59

variability plot

Answer 59

A measure of the difference between the amino acid sequences of different variants of a given protein. The most variable proteins known are antibodies and T-cell receptors.

Question 60

Wee1

Answer 60

Protein kinase that inhibits Cdk activity by phosphorylating amino acids in the Cdk active site. Important in regulating entry into M phase of the cell cycle.

Question 61

β strands

Answer 61

A secondary protein structure in which the polypeptide backbone of several consecutive amino acids is arranged in a flat, or planar, conformation, and often illustrated as an arrow.

Question 62

β turn

Answer 62

A type of protein secondary structure consisting of four amino acid residues arranged in a tight turn so that the polypeptide turns back on itself.

Question 63

γ-Carboxyglutamate

Answer 63

A posttranslationally formed amino acid in prothrombin and factors VII, IX, and X.