Molecular Biology: Central Dogma, Transcription, Translation, and DNA Replication

What is the central dogma of molecular biology?

Information flows from DNA to RNA to proteins.

Is translation the process of making mRNA from a DNA template strand?

No, that process is transcription.

Where are promoters and terminators found?

On the template strand.

When does translation occur?

When peptide bonds are formed.

Which of the following are types of RNA: mRNA, snRNA, tRNA, rRNA?

All of these are types of RNA.

What is the function of the 5' cap and the 3' poly-A-tail?

They protect mRNA from degradation.

What is the function of aminoacyl-tRNA synthetases?

They bind the correct amino acid to the empty tRNA.

Are snRNPs responsible for splicing out non-coding exon regions?

No, they are responsible for splicing out introns.

At which site do empty tRNA molecules leave the ribosome?

The E-site.

Where does transcription take place?

In the nucleus.

Does substituting an adenine nucleotide for a guanine nucleotide cause a frameshift mutation?

No, it causes a point mutation (substitution).

What is the significance of the start codon AUG?

All proteins begin with methionine.

Do all proteins begin with methionine and end with proline?

No, this is false.

If RNA polymerase reads the DNA sequence ATCTTA, what RNA sequence will it make?

UAGAAU.

The codon AUG matches with which anticodon?

UAC.

When a substitution mutation changes the codon CCC to CCA, and both code for proline, what type of mutation is this?

Silent mutation.

Where is the enzyme peptidyl transferase located?

On the large ribosomal sub-unit.

Where does translation take place?

In the cytoplasm, on a ribosome, and in prokaryotic cells.

Which enzyme is responsible for synthesizing the new DNA strand during replication?

DNA polymerase III

What is the primary function of the enzyme gyrase during DNA replication?

Relieves the torque from rapid untwisting

On which strand are Okazaki fragments found?

The lagging strand

Which enzyme is responsible for linking Okazaki fragments together?

DNA ligase

What did the Meselson-Stahl experiment demonstrate about DNA replication?

It is semi-conservative

Which enzyme is responsible for untwisting the DNA helix during replication?

Helicase

What does Chargaff's rule state?

G matches with C, and T matches with A

What type of bond links the 5' of one nucleotide to the 3' of the next nucleotide?

Phosphodiester bond

Why does replication proceed in opposite directions on the leading and lagging strands?

DNA polymerase III can only add to the 3' end of a strand

What are the common causes of mutations in DNA?

Copying mistakes, exposure to chemicals, or electromagnetic radiation

If a strand of DNA has the sequence AGTCCA, what is the complementary DNA strand?

TCAGGT

If a DNA molecule contains 40% thymine, what percentage of guanine does it contain?

10%

What is the consequence of a lack of telomerase activity in cells?

Chromosomes shorten during each division

List examples of potential mutagens.

UV light, chemicals, nicotine, and X-rays

What is the immediate consequence of a non-functional primase enzyme?

The DNA polymerase III enzyme would have nothing to bind to

What does the experiment of mixing a killed virulent strain of bacteria with a living benign strain demonstrate?

Cells can pick up genes from the environment