Test
Protein section 1
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Preguntas del test (34)
1FOUR MAJOR FUNCTIONAL GROUPS:
- ABinding
- BModification
- CCatalysis
- DSwitching
- EInhibition
- FStructural
- GPhysiological
2How is amide bond formed
- Adehydration
- Baddition
- Chydrolysis
- Doxidation
- Ereduction
3The acidity of the carboxylic acid is due to....
- Astability of the carboxylate anion relative to the acid
- Bthe charge of the carboxylate residue
- Coverall bonding
- Dcharge distribution
4when the charge of the carboxylate resides two equivalent electronegative oxygens the structure is called
- Aresonance form
- Bprotonated form
- Cchiral form
- Dassymetric form
5pKa values vary somewhat depending on
- Athe temperature of the solution
- Bthe precise molecular structure
- Cthe environment in which the acid-base chemistry is taking place.
- Dhow homogenous is the solution
6The corresponding carboxylate anion is more stable in the presence of the adjacent, positively charged, ammonium ion, therefore
- Athe carboxylic acid group of glycine is more acidic than a simple carboxylic acid since
- Bthe simple carboxylic acid is more acidic than the carboxylic acid group of glycine
7The effect of environment on pKa is particularly important in non-polar conditions such as..
- Athe interior of a protein
- Bthe outer part of the protein
- Cthe acidic part of the protein
- Dthe basic part of the protein
8What stereoisomers predominate in nature
- AL-amino acids
- BD-amino acids
9Into which groups can amino acids be divided
- Aamino acids with hydrocarbon side chains
- Bcarboxylic acid side chains
- Camide side chains
- Dacyclic with basic N containing side chains
- Ehydroxyl functional groups
- Fsuphur containing side chains
- Gnitrogen heterocycles and proline
- Hhydrophilic side chains
- Ihydrophobic side chain
- Jphosphorus containing side chains
10Which amino acid imparts unusual structural flexibility
- AGlycine
- BSerine
- CProline
- DGuanine
11What amino acid has two chiral centres due to the both of its α and β- carbons being asymmetric, and therefore has four possible stereoisomers.
- AIsoleucine
- BValine
- CGlutamine
- DCysteine
12Confer negative charge on proteins because their side chains are ionised at pH 7, under physiological conditions acidic side chains exist as the conjugate base
- Aaspartate
- Bglutamate
- Carginine
- Dhistidine
13The most basic of the 20 amino acids.
- AHistidine
- BLysine
- CArginine
- DAsparagine
14The pKa of this protein is around pH 7 and thus at physiological pH it can act as either an acid or a base. This makes it especially important in acid-base catalysis and it has an important role to play in many enzymes. It also forms complexes with zinc in proteins which has importance for both structure and mechanism.
- AHistidine
- BTryptophan
- CMethionine
- DGlutamine
- EAlanine
15Fill in the blanks
- AHistidine
- BArginine
- CProline
- DMethionine
- EIsoleucine
- FHistidine
- GProline
- HArginine
- IMethionine
- JIsoleucine
16Contains a non-polar methyl thioether group. This makes it one of the more hydrophobic amino acids
- Amethionine
- Bcysteine
- Cserine
- Dthreonine
- Amethionine
17The hydroxymethyl group of this amino acid does not appreciably ionise at physiological pH. Essentially hydrophilic.
- Amethionine
- Bcysteine
- Cserine
- Dthreonine
- Amethionine
18The side chain is somewhat hydrophobic, but also extremely reactive. It is polarisable and can lose its proton to bercome the thiolate anion. Can form disulphide bridges in proteins.
- Amethionine
- Bcysteine
- Cserine
- Dthreonine
- Amethionine
19Has two chiral centres and thus can have four stereoisomers
- Amethionine
- Bcysteine
- Cserine
- Dthreonine
- Amethionine
20The formation of disulphide bonds in proteins is an important [blank_start]secondary[blank_end] structural feature. This helps to impart [blank_start]stability[blank_end] and conformational rigidity to some proteins
- Asecondary
- Bprimary
- Cteriary
- Dquaternary
- Estability
- Facidity
- Greactivity
- Hinertness
21This amino acid is unique in that its three carbon side chain is bonded to both the α carbon and the α amino group. The heterocyclic pyrrolidine ring created restricts the geometry of polypeptides.
- Aproline
- Btyrosine
- Caspertate
- Dvaline
22This amino acid has a hydroxyl function associated with the phenol ring. Acid base chemistry is facilitated as the ring enhances the stability of the conjugate base. It can sometimes act as an acid.
- Atyrosine
- Bproline
- Ctryptophan
- Dphenyalanine
23[blank_start]Phe, Tyr and Trp[blank_end] are all highly aromatic and can absorb UV light at 280nm. Proteins have an optical density at 280nm because of these side chains
- APhe, Tyr and Trp
- BSer, Thr and Cys
- CVal, Leu, Ile
- DLys, Arg, His
24drag the appropriate amino acid to the blank space
- AProline
- BHistidine
- CIsoleucine
- DArginine
- ETyrosine
25The more [blank_start]hydrophobic[blank_end] amino acids have a tendency to be sequestered away from the solvent towards the [blank_start]centre[blank_end] of protein molecules. This provides one of the major driving forces for protein [blank_start]folding[blank_end]
- Ahydrophobic
- Bhydrophilic
- Ccentre
- Dinner part
- Eouter part
- Ffolding
- Gbinding
- Hinhibition
26[blank_start]Hydrophilic[blank_end] residues tend to interact with the solvent more easily via [blank_start]hydrogen[blank_end] bonding and thus can be on the [blank_start]outside[blank_end] of proteins.
- AHydrophilic
- Bhydrophobic
- Chydrogen
- Dcovalent
- Eoutside
- Finside
27Under [blank_start]physiological[blank_end] conditions this effectively restricts the [blank_start]peptide[blank_end] bond to one of two configurations: cis or trans
To minimise steric crowding due to close proximity of bulky groups on th carbonyl carbon and the nitrogen the [blank_start]trans[blank_end] form is favoursed, except where [blank_start]PROLINE[blank_end] is involved.- Aphysiological
- Bcellular
- Cpeptide
- Dionic
- Etrans
- Fcis
- GProline
- HHistidine
28
Proline has an [blank_start]alkyl[blank_end] chain rather than a [blank_start]hydrogen[blank_end] atom as the [blank_start]second[blank_end] substituent on nitrogen
In amides containing proline the [blank_start]cis[blank_end] form is not dramatically disadvantaged
In proteins about [blank_start]10%[blank_end] of all peptide bonds involving proline are cis.- Aalkyl
- Bcarboxyl
- Chydrogen
- Doxygen
- Esecond
- Fthird
- Gcis
- Htrabs
- I10%
- J15%
- K5%
29THE SHAPE OF POLYPEPTIDES IS DEFINED BY [blank_start]ROTATION[blank_end] ABOUT THE C-N AND C-C BONDS
- AROTATION
- BSPIN
- CSIDE CHAIN
- DMOMENTUM
30 All atoms around the peptide bond lie in a [blank_start]planar[blank_end] conformation.
This rotation is described by the torsion angles φ Phi between [blank_start]C-N[blank_end] and ψ Psi between [blank_start]C-C.[blank_end]
If all psi and phi angles are the same the peptide assumes a [blank_start]repeated[blank_end] structure.
For certain combinations of angles this can take the form of a [blank_start]helical stucture (the alpha helix)[blank_end] or a beta-sheet structure.
Clearly the peptide structure exhibits [blank_start]flexibility[blank_end] and this is important for the complex [blank_start]structure[blank_end] of proteins.- Aplanar
- Bprimary
- Ccis
- Dtrans
- EC-N
- FC-C
- GC-C.
- HC-N.
- Irepeated
- Jsaturated
- Khelical stucture (the alpha helix)
- Lcoil structure
- Mflexibility
- Nmotitlity
- Ostructure
- Pbinding
31What characteristic of atoms and groups of atoms limits the possible psi and phi torsion angles that the backbone of the polypeptide chain can adopt without causing protruding R groups to bump into each other.
- AThe physical size
- BThe chemical properties
- CThe amount
- DThe flexibility
32The Ramachandran plot shows the allowed
- Apsi and phi angles
- Bcarboxyl and amino groups
- Csecondary structure of the protein
- Dbinding of the protein
33Label the chemical structure
- ASide chain
- BAlpha carbon
- Calpha-amino group
- Dalpha-carboxylate
34Amino acids with basic R groups
- ALysine
- BHistidine
- CArginine
- DPhenylalanine
- EValine
- FSerine
- GAspargine
Información
- Descripción
- 1st year Biochemistry and molecular biology Test sobre Protein section 1, creado por MrSujg el 19/11/2015.
- Autor
- MrSujg
- Idioma
- English
- Visitas
- 395
- Historial
- Creado el 19 nov 2015 · actualizado el 17 ago 2017
- Etiquetas
- Valoración
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