The Central Dogma of Molecular Biology

Question 1

What is the flow of genetic information from DNA to phenotype?

Answer 1

DNA is replicated (requires DNA pol) and then with the help of RNA polymerase transcription occurs - DNA to RNA. The final step in DNA to phenotype would be RNA to protein which is called translation and aminoacyltransferase is the enzyme used.

Question 2

The general purposes of DNA/RNA/proteins

Answer 2

DNA - can store information
RNA - can transduce DNA messages into protein
Protein - can read into and catalyze reactions as ribozymes

Question 3

What enzyme is used to go from RNA to DNA

Answer 3

retrotranscriptase

Question 4

What did Francis Crick state?

Answer 4

that information in DNA is unidirectionally transferred to RNA molecules during transcription and to proteins during translation

Question 5

RNA can _____ itself

Answer 5

replicated

Question 6

Ribozyme

Answer 6

catalytic RNA

Question 7

RNA can be retro transcribed to DNA by…

Answer 7

retrotranscriptase

Question 8

What enzyme is used to convert DNA to RNA

Answer 8

RNA polymerase

Question 9

What is the job of RNA pol.

Answer 9

to decode DNA to RNA

Question 10

What is the difference between a normal prion protein and a disease-causing prion

Answer 10

Normal prion is a phosphatidylinositol - anchored protein that is water-soluble

Disease-causing prion is misfolded and resistant to proteolysis

Question 11

RNA is made up of…

Answer 11

Pentose ring nitrogenated base, and a phosphate group

Question 12

Ribonucleotides

Answer 12

consists of the RNA monomers + are linked by covalent phosphodiester bonds to form the RNA polymers

Question 13

What type of bond is between ribonucleotides

Answer 13

covalent phosphodiester bonds

Question 14

What makes RNA less structurally stable than DNA?

Answer 14

The nitrogenated bases in a single-stranded RNA do not have a partner to readily form h-bonds with, therefore, RNA is prone to react with other nucleic acids

Question 15

Where is RNA synthesized

Answer 15

in the nucleus and then transported to the cytoplasm

Question 16

The 5 types of RNA molecules involved in translation + their function

Answer 16

1. mRNA - intermediated that carry genetic information from DNA to ribosomes
2. snRNA - structural components of spliceosomes
3. tRNA - ADaptors between amino acids + the codons in mRNA
4. rRNA - structural and catalytic compounds of ribosomes
5. miRNA - short single-stranded RNAs that block expression of complementary mRNAs

Question 17

What is the different nucleotides found in RNA vs. DNA

Answer 17

RNA has Uracil and DNA has Thymine

Question 18

Guanosine

Answer 18

is a purine DNA nucleoside used to synthesize the guanosine triphosphate (GTP) by phosphorylation

Question 19

3 major difference between RNA and DNA

Answer 19

1. Single-stranded vs. double
2. OH group vs. H
3. Uracil vs. Thymine

Question 20

What is the sense (+) RNA

Answer 20

the sense (+) RNA is complementary to the template strand (DNA)

Question 21

Overview steps of the replication fork

Answer 21

1. Helicases unwind the parental double helix
2. Single-strand binding proteins stabilize the unwound parental DNA
3. The leading strand is synthesized continuously in the 5’ -> 3’ direction by DNA polymerase
4. The lagging strand is synthesized discontinuously. Primase synthesizes short RNA primers which are extended by DNA polymerase to form an Okzazki fragment
5. After the RNA primer is replaced by DNA pol. DNA ligase joins the Okazaki fragment to the growing strand

Question 22

Holoenzyme + its function

Answer 22

Holoenzyme is a catalytically active enzyme that consists of apoenzyme and cofactor

Function - to change substrate into product.

Question 23

DNA polymerase III holoenzyme

Answer 23

(Pol III HE) is an enzyme that catalyzes the elongation of DNA chains during bacterial chromosomal DNA replication

Question 24

The purpose of all the holoenzyme subunits

Answer 24

Sigma - initiation of transcription (release after)

Alpha - assembly of the tetrametric core

Beta - Ribonucleotide triphosphate binding site

Beta’ - DNA template binding region

W - chaperone activity (control correct folding of B’)