Theme 2A

Question 1

Central Dogma

Answer 1

universal information flow from DNA to protein in order to convert genotype to phenotype

Question 2

Where does translation and transcription occur in prokaryotes?

Answer 2

cytoplasm and can occur simultaneously

Question 3

Where does translation and transcription occur in eukaryotes?

Answer 3

transcription and processing of precursor mRNA molecules occurs in nucleus and translation occurs in the cytoplasm

do not happen simultaneously

Question 4

1896 Garrod studied a hereditary disease called alkaptonuria. Patients inherit a ____________ resulting in abnormal cellular metabolism

Answer 4

mutated gene coding for a defective enzyme

Question 5

1940s Beadle and Tatum hypothesized that genes encode enzymes that function at each __________ needed to make an essential nutrient

Answer 5

step of a biochemical pathway

Question 6

Review diagram on slide 3

Question 6

Mutating a gene encoding an enzyme would cause a _______ in the metabolic pathway and the organism can no longer synthesize the needed nutrient (__________)

Answer 6

block; auxotroph

Question 7

Isolation of arginine auxotrophic mutants essential to life

Answer 7

• Involved isolating mutants that failed to grow in the absence of arginine
• each mutant has defective gene for enzyme needed to synthesize an intermediate product to produce arginine

Question 8

Understand diagram of Precursor - Arginine pathway on slide 4

Question 9

Genes encode for which two types of RNA?

Answer 9

coding (mRNA) & non-coding (tRNA, rRNA, snRNA, microRNA)

Question 9

coding rna

Answer 9

codes for protein/polypeptide through translation

Question 9

Information for the genetic code is contained in _______________ in DNA or RNA sequences

Answer 9

4 nucleotide bases

Question 9

non-coding rna

Answer 9

does not code for protein

Question 9

DNA has a three-letter code called a

Answer 9

triplet

Question 9

RNA has a three letter code called a

Answer 9

codon - refers to mRNA

Question 10

Genetic code is _______-

Answer 10

universal

Question 11

Universal genetic code cal allow foreign genes to be __________ and ______________ in different host organisms

Answer 11

transferred; expressed

Question 12

For every gene, a RNA molecule is transcribed from ___________.

Answer 12

the template strand

Question 13

The other DNA strand is called the ________ and has the same orientation and sequence as mRNA molecules except _______ is substituted with _____-.

Answer 13

non-template/coding strand; uracil; thymine

Question 14

mRNA is synthesized in the _____ direction by __________-

Answer 14

5’-3’; RNA polymerase

Question 15

Do u know how to identify which is template strand?

Answer 15

slide 8

Question 16

On chromosomal maps, genes are shown on the ________ strand

Answer 16

coding

Question 17

Reverse transcription

Answer 17

RNA –> DNA

• reverse transcriptase is found in viruses with RNA genomes
• doesn’t have proofreading so it generates lots of mutations
• viral RNA needs to be converted into viral DNA in order to integrate into host’s chromosome
• host’s transcription and translation machinery is hijacked to produce viral proteins from viral DNA

Question 18

3 important enzymes in the life cycle of HIV

Answer 18

reverse transcriptase, integrase, protease

Question 19

Life Cycle of SARS-CoV-2

Answer 19

• doesn’t have lysogeny
• genome = + sense ssRNA (same sequence as mRNA)
• 28 viral proteins
• RNA-dependant - RNA polymerase synthesizes - sense ssRNA for viral transcription and replication
  (reads a template RNA strand, converts + strand to - strand)
• ACE2 receptors are abundantly expressed in alveolar lung cells, heart cells, and intestinal cells

Question 20

What came first - DNA or RNA?

Answer 20

likely RNA because besides being able to store genetic info (code for aa like DNA), it also catalyzes reactions (not very stable)

• so if there is mutation in RNA, it can’t be fixed cuz its single stranded

DNA developed later with more advantages, ie. more stable, double stranded that allows complementary strand to be used as template for repair of damaged strand

Question 21

Ribozymes (ribonucleic acid enzymes)

Answer 21

can catalyze their own synthesis and cleave RNA molecules (2 deg. structure)