Nucleic Acid Notes

Which of the following correctly describes the directionality of DNA synthesis by DNA polymerase?

3' → 5' template read, 5' → 3' synthesis

A nucleotide differs from a nucleoside in that a nucleotide contains:

A phosphate group

In the Chargaff's rules, which base-pairing rule is VIOLATED in single-stranded RNA?

[A]=[T] and [G]=[C]

Which type of RNA has the SHORTEST half-life and is most rapidly degraded in prokaryotes?

mRNA

The antiparallel nature of the DNA double helix means that:

One strand runs 5'→3' while the complementary strand runs 3'→5'

Which of the following is NOT a post-transcriptional modification of eukaryotic pre-mRNA?

Methylation of the -10 Pribnow box

Which nucleotide base is found in RNA but NOT in DNA?

Uracil

The B-form of DNA has approximately how many base pairs per turn?

10

Okazaki fragments are synthesized on which strand during DNA replication, and in what direction?

C. Lagging strand, 5'→3'

Which enzyme is responsible for removing RNA primers during DNA replication in prokaryotes?

DNA Polymerase

Z-DNA differs from B-DNA primarily in that Z-DNA:

Is a left-handed helix

In the central dogma of molecular biology, which process is described as 'reverse transcription'?

RNA → DNA

The enzyme that unwinds the DNA double helix at the replication fork by breaking hydrogen bonds between base pairs is called ______.

Helicase

The ______ bond connects the nitrogenous base to the pentose sugar in a nucleoside.

N-glycosidic (beta-N-glycosidic) bond

In eukaryotes, the RNA polymerase responsible for transcribing ribosomal RNA (rRNA) genes — except the 5S rRNA — is RNA Polymerase ______.

I (One)

The ______ structure of tRNA, formed by the folding of the anticodon loop and acceptor stem, is the functional tertiary form of tRNA.

L-shaped (inverted L or cloverleaf in secondary; L-shaped in tertiary)

The Tm (melting temperature) of a DNA duplex is higher when it has a higher content of ______ base pairs.

G-C (guanine-cytosine)

The 5' cap added to eukaryotic mRNA consists of ______ connected via a 5'–5' triphosphate linkage.

7-methylguanosine (m7G)

DNA topoisomerase II relieves torsional stress during replication by introducing ______ breaks in the DNA.

Double-strand breaks (transient

The segment of DNA between two consecutive nucleosomes, not wrapped around the histone core, is called ______ DNA.

Linker DNA