DNA Replication, Transcription, and Translation: Key Concepts for Biology

What is the site on the DNA where replication begins?

Origin of replication

In which direction does replication proceed?

Both directions

Which strands are continuous and discontinuous during replication?

Leading strand is continuous; lagging strand is discontinuous

What protein recognizes the origin of replication?

Initiator protein

What proteins prevent DNA strands in the replication bubble from re-annealing?

Single-strand binding proteins

What specific bacterial enzyme relieves supercoiling?

Gyrase

What is the enzyme catalyzing strand elongation?

DNA polymerase

What are the DNA fragments formed on the lagging strand called?

Okazaki fragments

What enzyme joins Okazaki fragments?

Ligase

What are the two ways the cell prevents errors in replication?

Proof-reading and mismatch repair

What is the direction of DNA synthesis?

5' to 3'

Is DNA replication conservative, semi-conservative, or dispersive?

Semi-conservative

Can DNA polymerase start polymerization de novo?

No, it requires a primer

What is transcription?

The process of DNA to mRNA

What enzyme catalyzes transcription?

RNA polymerase

Where does RNA polymerase bind to the DNA to start transcription?

Promoter

What gives RNA polymerase specificity for binding the promoter in bacteria?

Sigma factor

Are all RNA transcripts used to make protein?

No, some are mRNA and some are tRNA

What does polycistronic mean?

It transcribes more than one polypeptide

What is an operon?

A unit that includes regulatory and structural genes

Is bacterial mRNA stable?

No

What is a promoter?

The RNA polymerase binding site

What catalyzes translation?

Ribosome

In bacteria, can translation begin before transcription of the mRNA is complete?

True

What sequence does the ribosome recognize and bind to in bacteria?

Shine-Dalgarno sequence

What part of the ribosome binds the Shine-Dalgarno sequence?

16S rRNA

What type of bond is formed between amino acids to make a protein?

Peptide bond

What signals the start and end of translation?

Start and stop codons

What is the first amino acid to start translation of every bacterial peptide?

Methionine

How many nucleotides are in a codon?

3