The peptide bond in proteins is a) nonpolar, and fixed in a trans conformation. b) nonpolar, but rotates to three preferred dihedral angles. c) planar, and usually found in a trans conformation. d) planar, but rotates to three preferred dihedral angles.
1 3843If the enthalpy change for a reaction is zero, DG? is equal to: a) DH? b) lnKeq c) TDS? d) -TDS?
1 3727The nucleophile in the first stage of the serine protease mechanism is a) H2O b) the carboxyl of Asp 102 c) the hydroxyl of Ser 195 d) the imidazole of His 57
2083The elution volume of an enzyme on a gel filtration column can be predicted from a) its enzyme activity b) its protein absorbance at 280 nm c) subunit composition and monomer molecular mass(es) d) Choices a) and b) are both correct.
3213DNA binding by proteins with the helix-turn-helix (HTH) motif does not involve a) altered stacking of the DNA at the center of symmetry. b) hydrogen bonds, salt bridges, and van der Waals contacts. c) interactions with base pairs in the major groove of DNA. d) interactions with the sugar-phosphate backbone of DNA.
2061The two exonuclease activities of DNA polymerase I a) are coupled during the formation of "gapped DNA". b) degrade DNA in a 5' --> 3' direction. c) degrade DNA in a 3' --> 5' direction. d) occur at two different active sites.
1 3202A principal difference between prokaryotic and eukaryotic DNA replication is a) completely different proteins/enzymes in eukaryotes b) multiple origins in eukaryotes c) no requirement for topoisomerase activity in prokaryotes d) the absence of a nucleus in prokaryotes
9 36427When s subunit dissociates from an initiated RNA polymerase, a) it can bind a core enzyme to reform holoenzyme. b) it hydrolyzes ATP until rebound by core enzyme. c) it leaves behind an elongating species complexed with Rho factor. d) it remains bound to the promoter consensus sequence.
1 3690The junction between the two helical portions of tRNA is stabilized by many non-standard base-base interactions between residues in the a) anticodon and CCA ends. b) helical stems of the D and Anticodon stems. c) loops of the Anticodon and Acceptor stem. d) loops of the TYC and D arms.
1 3901On the ribosome, mRNA binds ____; the peptidyl transferase reaction occurs ____. a) to the large subunit; on the small subunit. b) to the small subunit; on the large subunit. c) between the subunits; on the large subunit. d) between the subunits; on the small subunit.
2 5974According to the fluid mosaic model of cell membranes, which type of molecule spans the membrane from its inner to outer surface? a) cholesterol b) phospholipid c) protein d) triacylglycerol
1 5363Post New Bio Chemistry Questions
How is the cooling of organs and tissues for medical transplantations associated with the effect of temperature upon enzymatic reactions?
How do hydrophobic and hydrophilic residues arrange themselves in globular proteins?
How can you determine the reaction, taking place at constant pressure delta (h)?
Which compound is involved in reducing levels of homocysteine in the blood?
What causes the elasticity of corneal layer of skin?
what is meant by codan optimisation m rna enrichment?
Garnet is the ore of which element. Give its chemical formula.
Which organ and subcellular site are most important for fatty acid biosynthesis?
What is the process, by which aluminium is refined?
A 3.00 * 10-6M solution in a 1.0 cm cuvette read 16 % T at 620nm. What were the absorbance and the molar absorbancy index of the solution?
which fat soluble vitamin has co-enzymic function?
What is the relation between vitamins and enzyme cofactors?
In which forms arsenic impurities present in drug.
All technical,written test questions
What is the importance of enzymes for the living beings?