Which enzyme primarily is responsible for joining "Okazaki fragments" during the DNA replication process?
DNA ligase
During DNA replication the lagging strand is synthesised discontinuously in short pieces called Okazaki fragments, because DNA polymerase can add nucleotides only in the 5′ to 3′ direction.
DNA ligase joins these fragments by forming a phosphodiester bond between the 3′-OH end of one fragment and the 5′-phosphate end of the next, sealing the nicks to give a continuous strand.
DNA polymerase synthesises new DNA and fills gaps but cannot seal the final nick, helicase unwinds the double helix, and primase lays down the short RNA primers.
Hence, the enzyme is DNA ligase.
Important Questions from Biomolecules
The chemical name of Vitamin D 3is:
Which of the following food comes under complex carbohydrate?
I. Potatoes
II. Sweets
III. Pasta
IV. Wheat
Following are the pKa's of the ionizable groups in lysine
pKa 1 = 2.16 (α - carboxylic group)
pKa 2 = 9.06 (α - amino group)
pKa 3 = 10.54 (ε - amino group)
Which one of the following options represents the pl of lysine?
How many hydrogen bonds involving the backbone CO and NH can be observed in an α‐helix consisting of 15 amino acid residues?
In eukaryotic cells, covalently attached lipids help to anchor some water soluble proteins to the plasma membrane. One group of cytosolic proteins are anchored to the cytosolic face of membrane by a fatty acyl group (e.g. myristate or palmitate). These groups are generally covalently attached to which amino acids present at the N‐terminus of the polypeptide chain?
