Test
Biochem Midterm March 2020
Este test tiene tipos de pregunta que se abren en el reproductor de siempre.
Preguntas del test (46)
1in cation exchange the stationary phase is positively charged
- AVerdadero
- BFalso
2What is the purpose of B mercaptotethanol in the anfinsen experiment
- AReducing agent
- BBreaking disulphide bonds
- CBreak/prevents H bonds
- DBreaks/prevents ionic bonds
3Hydroxy proline has [blank_start]2[blank_end] important roles in collagen
- A2
4an amino acid with an amino group in its side chain (pka 6) will be [blank_start]neutral[blank_end] at pH 7
- Aneutral
- Bnegative
- Cpositive
5the P50 of hemoglobin/myoglobin is
- Athe oxygen saturation at 50 mmHg PO2
- Bthe partial pressure of oxygen at 50% saturation
62,3-bisphosphoglycerate decreases affinity for oxygen in hemoglobin
- AVerdadero
- BFalso
7decreasing the affinity for oxygen in hemoglobin would do what to the oxygen binding curve?
- ACurve would shift up
- Bcurve would shift down
- Ccurve would shift left
- Dcurve would shift right
8What is (approximately) the PI of this amino acid?
- A2.3
- B9.6
- C6
- D1.0
9What is happenning at the labeled spot? This is the titration curve of an amino acid with an amino group in the side chain.
- ACOO- in amino acid is protonated
- BNh2 in side chain is protonated
- Cnh2 in Amino acid is protonated
10Edman degradation uses a [blank_start]chemical[blank_end] to remove residues [blank_start]1[blank_end] at a time
- Achemical
- BAmino acid specific protein
- C1
- D2
- E5
11Order these steps in an Edman Degredation...
[blank_start]1.[blank_end] terminal amino acid reacts with phenyl isothiocyanate
[blank_start]4.[blank_end] cyclic compound is identified
[blank_start]2.[blank_end] basic conditions lead to a cyclic structure forming
[blank_start]3.[blank_end] acid and heat cause release of terminal amino acid from peptide- A1.
- B2.
- C3.
- D4.
- E2.
- F3.
- G4.
- H1.
- I3.
- J4.
- K2.
- L1.
- M3.
- N1.
- O4.
- P2.
12Anion exchange has a negative stationary phase
- AVerdadero
- BFalso
13Rate of enzyme converting substrate to product = [blank_start]Kcat[blank_end]
Rate of enzyme binding to substrate = [blank_start]Kon[blank_end]
Rate of enzyme releasing substrate = [blank_start]Koff[blank_end]
Enzyme affinity for substrate = [blank_start]Km[blank_end]- AKcat
- Bkon
- CKOff
- DKm
14Vo is obtained by taking the slope at the [blank_start]beginning[blank_end] go the [P] vs time graph
- Abeginning
- Bplateau
- Cmidpoint
15When concentration of substrate is very high, Vo is [blank_start]equal to[blank_end] Vmax.
- Aequal to
- Blarger than
- Cless than
16When concentration of substrate is equal to the affinity constant, Vo is [blank_start]twice[blank_end] Vmax.
- Atwice
- Bhalf
- Cequal to
17When [enzyme] changes, which of these also changes?
- AVmax
- BKm
- CKcat
- DVo
18what is true about the specificity constant?
- Adepends of rate of catalysis and affinity
- Blow number is means it is a "good" enzyme
- CA high Km will give a high specificity constant
- D=Kcat/Km
19what are the six major classes of enzymes
- AOxidoreductases, transferases, Oxidases, protonases, ligases, hydroxylases
- BOxidoreductases, transferases, Hydrolyases, ligases, Isomerases, lyases
- CLyases, Oxidases, hydroxylases, Lipases, amylases, ligases
- Dtransferases, isomerases, carbohydrases, hydrolyases, oxireductases, ligases
20For enzymes that require a cofactor, the enzyme alone is called a(n) [blank_start]apo[blank_end] enzyme, and the enzyme cofactor complex is called a(n) [blank_start]holo[blank_end] enzyme
- Aapo
- Bprosthetic
- CHolo
- DFunctional
21Cofactors can be either vitamins or minerals
- AVerdadero
- BFalso
22∆G is the difference between free energy of product and reactants
- AVerdadero
- BFalso
23A non-spontaneous reaction is exergonic
- AVerdadero
- BFalso
24the more negative the ∆G, the faster the reaction
- AVerdadero
- BFalso
25What can affect ∆G?
- ATemperature
- Bcatalyst
- C[reactant]
- D[product]
26Can ∆G be zero?
- AVerdadero
- BFalso
27∆G‡ is
- Athe free energy of the transition state
- Bthe difference in free energy of the reactants and products
- Caffected by the addition of an enzyme/catalyst
28Which of these amino acids are ionizable?
- ALysine
- BGlutamine
- Ctryptophan
- DCysteine
- EArginine
29KD (Dissociation constant) is used to compare affinity in [blank_start]non-catalytic[blank_end] reactions. KD = [blank_start]Koff[blank_end]/[blank_start]Kon[blank_end]
- Anon-catalytic
- Bcatalytic
- CKoff
- DKon
- EKon
- FKoff
30The upper limit of Kcat/Km (specificity constant) is ...
- A10^-5 /s/M
- B10^9 /s/M
- C10^14 /s/M
31Which of these amino acids can H bonds, but are not ionizable?
- AW
- BS
- CY
- DC
- EN
- FQ
- GK
- HR
32Which amino acids are neutral in charge, no matter the pH?
- AAla
- BGly
- CLeu
- DPhe
- ELys
- FAsp
33The first amino acid in all proteins is [blank_start]methionine[blank_end]
- Amethionine
- Bcysteine
- Ctryptophan
- Dthreonine
34Methionine can be oxidized to [blank_start]methionine sulfoxide[blank_end]
- Amethionine sulfoxide
35free amino acids at neutral pH exist predominantly in the [blank_start]zwitterionic[blank_end] form
- Azwitterionic
36Amino acid composition analysis
[blank_start]1.[blank_end] peptide is hydrolyzed into individual amino acids using heat and acid
[blank_start]2.[blank_end] amino acids are separated by ion exchange or high pressure liquid chromatography
[blank_start]3.[blank_end] amount of amino acids measured- A1.
- B2.
- C3.
37Edman degradation can be used for peptides as long as 100 amino acids long
- AVerdadero
- BFalso
38Mass spectrometry measures [blank_start]acceleration[blank_end] of [blank_start]ionized[blank_end] molecules in the [blank_start]gas[blank_end] phase as they move through an electric field to determine [blank_start]mass[blank_end]
- Aacceleration
- Bvelocity
- Cionized
- Dneutral
- Egas
- Fliquid
- Gsolid
- Hmass
- Iidentity
39Mass spectrometry can be used to sequence proteins
- AVerdadero
- BFalso
40alpha carbons of amino acids in a peptide bond are usually...
- Acis
- Btrans
- Cparallel
- Dperpendicular
41What are stabilizing forces in secondary structure but not tertiary structure in a protein?
- Aionic attractions between opposite charged side chains
- BH bonds between oxygen of the backbone carbonyl and the hydrogen of the backbone amine
- CH bonds between side chains
- Dhydrophobic interactions between non polar side chains
42Fetal hemoglobin has 2 alpha subunits and 2 [blank_start]gamma[blank_end] subunits as opposed to Adult hemoglobin which has 2 alpha and 2 [blank_start]beta[blank_end]
- Agamma
- Bbeta
43tertiary structure is formed by interactions between R groups
- AVerdadero
- BFalso
44Quaternary structure is made by interactions between subunits
- AVerdadero
- BFalso
45Which of these features are true about the structure of collagen
- AMade of 3 polypeptides each arranged in a left hand helix
- BEvery 4th residue is a glycine
- Crich in proline and hydroxyproline
- Dthe 3 chains arrange in a right hand helix around each other
46Myoglobin is mainly hydrophobic in the interior
- AVerdadero
- BFalso
Información
- Descripción
- Test sobre Biochem Midterm March 2020, creado por lyndsey chesham el 03/03/2020.
- Autor
- lyndsey chesham
- Idioma
- English
- Visitas
- 36
- Valoración
- Aún sin valoraciones Valora este test