Biochemistry of the Genome - Transcription, Translations + Mutations (Day 11)

Question 1

DNA is ____

Answer 1

Double-stranded, helix shape

Question 2

RNA is ____

Answer 2

Single-stranded, can fold on itself

Question 3

What does messenger (mRNA) do?

Answer 3

Serves as an intermediary between DNA and Protein; Used by ribosomes to direct synthesis of protein it encodes.

Question 4

What does transfer (tRNA) do?

Answer 4

Carries correct amino acids to the site of protein synthesis in the ribosome.

Question 5

What does ribosomal (rRNA) do?

Answer 5

Ensures proper alignment of mRNA, tRNA, and ribosomes during synthesis. (catalyzes peptide bond formations between amino acids)

Question 6

How can RNA serve as hereditary information?

Answer 6

for viruses that lack DNA

Question 7

How is RNA synthesized using DNA as a template?

Answer 7

Via transcription.

Question 8

What is the genetic code?

Answer 8

relationship between mRNA codon and it corresponding amino acid

Question 9

Why is the genetic code universal?

Answer 9

Several mRNA codons code for the same amino acid

Question 10

In translation what is Initiation?

Answer 10

Transitional complex forms, and tRNA

Question 11

In translation what is Elongation?

Answer 11

tRNAs bring amino acids one by one to add to the polypeptode chain.

Question 12

In translation what is Termination?

Answer 12

Release factor recognizes stop codon, the transitional complex dissociates, and completed polypeptides are released.

Question 13

Translation in prokaryotes

Answer 13

70S, translation and transcription occur simultaneously (rapid cellular response)

Question 14

Translation in Eukaryotes

Answer 14

80S, localized to cytoplasm

Question 15

What do Tetracyclines do?

Answer 15

Bind to 30S ribosomal subunit and block tRNA bonding

Question 16

What do Aminoglycosides do?

Answer 16

Bind to 30S ribosomal subunit, impairs proofreading and results in faulty proteins

Question 17

What do Chloramphenicol, Macrolide, and lincosamides do?

Answer 17

Bind to 50S ribosomal subunit, prevents peptide bond formation

Question 18

What is a point mutation?

Answer 18

Change in a singular nucleotide

Question 19

What is a main shift mutation?

Answer 19

additions or delations of nucleotides that cause a shift in the reading frame

Question 20

What is a silent mutation?

Answer 20

No change in the protein sequence

Question 21

What is a missense mutation?

Answer 21

Change to the amino acid sequence

Question 22

Nucleotide excision repair is ….

Answer 22

Dark repair, allows cells to excise DNA lesions including CPDs

Question 23

Photoreactivation is ….

Answer 23

Light repair, carried out by an enzyme called DNA photolyase.

Question 24

How do different mutagens act?

Answer 24

Breaks in the backbone of DNA due to the formation of hydroxyl radicals, modify bases, non-specific in damaging DNA, proteins, and other cellular components

Question 25

What is frameshift mutation?

Answer 25

Insertion or delation of one or more bases

Question 26

What is Irradiation?

Answer 26

UV radiation causes thymine dimers in DNA, leading to lethal mutations in exposed microbes.

Question 27

What is Alkylating?

Answer 27

Replace hydrogen atoms with alkyl groups (used in strong disinfectants)

Question 28

What is the primary mode of action of nonionizing radiation?

Answer 28

make thymine dimers

Question 29

What is the position within a codon in which changes often result in the incorporation of the same amino acid into the growing polypeptide called?

Answer 29

wobble position

Question 30

What is typically the first codon on the DNA template strand that signals the start for a protein?

Answer 30

TAC

Question 31

Stop codon recognized by a

Answer 31

releasing factor

Question 32

As used tRNAs move into the E site they are

Answer 32

released

Question 33

The first amino acid is always

Answer 33

methionine

Question 34

To begin translation the Met-tRNA binds the

Answer 34

P site

Question 35

The second charged tRNA binds the

Answer 35

A site

Question 36

The decoding center consists of which three sites

Answer 36

A, P, E

Question 37

start codon

Answer 37

AUG

Question 38

Transcription termination relies on a

Answer 38

hairpin loop at the end of the mRNA

Question 39

Sigma factors are necessary for

Answer 39

the recognition of a

promoter

Question 40

Transcription initiation begins at a

Answer 40

promotor