Central Dogma of Molecular Biology

Question 1

How does a single faulty gene result in the dramatic appearance of this albino raccoon?

Answer 1

Most likely had a mutation in the protein Tyrosine which codes for melanin (dramatic changes in appearance are caused by mutations)

Question 2

Gene expression

Answer 2

The process by which DNA directs protein synthesis in two stages, transcription and translation

Question 3

Transcription

Answer 3

The synthesis of RNA under the direction of DNA

Question 4

Translation

Answer 4

The synthesis of proteins under the direction of RNA

Question 5

Why did the Nobel Prize in 1958 go to Bradley and Tatum?

Answer 5

Because of their work in 1941 that revealed the fundamental relationship between genes and proteins - that genes regulate enzymatic events

Question 6

What is the one-gene-one enzyme hypothesis?

Answer 6

That the function of a gene is to dictate production of a specific enzyme
Later was revised to the one-gene-one protein then one-gene-one polypeptide hypothesis

Question 7

How is RNA different from DNA?

Answer 7

RNA used the sugar ribose instead of the deoxyribose in DNA
RNA had the nitrogenous base uracil instead of thymine

Question 8

What is the triplet code?

Answer 8

A series of non-overlapping, three-nucleotide words

Question 9

Can one species read the DNA code from a second species?

Answer 9

Yes because the genetic code is universal

Question 10

Transgenic

Answer 10

The introduction of foreign DNA into the genome of an organism

Question 11

What are the three steps of transcription?

Answer 11

Initiation, Elongation, Termination

Question 12

Initiation

Answer 12

Involving the attachment of RNA polymerase to the promoter and the start of RNA synthesis
RNA synthesis begins after RNA polymerase attaches to the promoter

Question 13

Elongation

Answer 13

As the newly formed RNA strand grows
Using the DNA as a template, RNA polymerase adds free RNA nucleotides one at a time

Question 14

Termination

Answer 14

When RNA polymerase reaches the terminator DNA and the polymerase molecule detached from the newly made RNA strand and the gene
RNA synthesis ends when RNA polymerase reaches the termination DNA sequence

Question 15

X-chromosome inactivation

Answer 15

One X-chromosome is inactivated by addition of methyl groups

Question 16

What we’re the first (and only) permitted farmed GMO animal on the USA?

Answer 16

Transgenic salmon (AquaBounty)
Inserted a growth hormone producing gene form Chinook salmon under the control of promoter from a cold-adapted fish species to produce Atlantic salmon that grow fast year round

Question 17

Messenger RNA (mRNA)

Answer 17

Encodes amino acid sequences and conveys genetic messages from DNA to the translation machinery of the cell

Question 18

Whats the difference In DNA translation in prokaryotes and eukaryotes?

Answer 18

Prokaryotes - it occurs in the same place that mRNA is made
Eukaryotes - mRNA must exit the nucleus via nuclear pores to enter cytoplasm

Question 19

Introns

Answer 19

Interrupting sequences that separate exons

Question 20

Exons

Answer 20

The coding regions

Question 21

RNA splicing

Answer 21

Removes introns and joins exons to produce a continuous coding sequence

Question 22

Alternative RNA splicing

Answer 22

Produces different mRNAs from the same transcript, results in the production of more than one polypeptide from the same gene, and is very common in humans

Question 23

RNA processing

Answer 23

Enzyme in the eukaryotic nucleus modify pre-mRNA before export to cytoplasm

Question 24

What does the Pfizer mRNA vaccine use instead of uracil?

Answer 24

Uridine analogy 1-methyl-3’-pseudouridylyl

Question 25

What did The Human Genome Project reveal about not human genomes?

Answer 25

That most of the human genomes does not consist of genes

Question 26

What was early estimates of human gene numbers based on?

Answer 26

Sequencing mRNA molecules, cDNAs arising from splice variants were often counted as separate genes

Question 27

Transfer RNA

Answer 27

A strand of RNA that forms a structure that:
Picks up a specific amino acid and using a special triplet of bases called an anticodon, inserts the amino acid at the appropriate position in the coding sequence

Question 28

Where does translation occur?

Answer 28

On the surface of the ribosome

Question 29

Ribosomes role in translation:

Answer 29

Ribosomes coordinate the functioning of mRNA and tRNA and, ultimately the synthesis of polypeptides
Ribosomes have two subunits: small and large
Each subunit is colosseum of divisional RNAs and proteins

Question 30

What are the three phases of translation?

Answer 30

Initiation, Elongation, and Termination (same as transcription)

Question 31

Initiation (RNA)

Answer 31

Brings together mRNA , a tRNA bearing the first amino acid, and the two subunits of a ribosome

Question 32

Elongation (RNA)

Answer 32

The messenger RNA moves between the two ribosomal subunits and the polypeptide chain grows as more tRNA is brought in

Question 33

Termination (RNA)

Answer 33

The ribosome reaches a stop codon in mRNA and the release factor promotes hydrolysis