WEEK 9 - FROM DNA TO RNA

Question 1

What are the means by which cells express genetic instructions?

• These processes involve copying a gene into RNA and then translating that RNA into a protein.

Answer 1

Transcription and Translation

Question 2

What is the process of producing RNA molecules from DNA called?

• This is the first step in gene expression.

Answer 2

Transcription

Question 3

What type of polymer is RNA?

• These subunits are linked together by phosphodiester bonds.

Answer 3

Linear polymer (made of four different types of nucleotide subunits)

Question 4

What sugar do ribonucleotides in RNA contain?

Answer 4

RIBOSE

Question 5

Which base is found in RNA instead of thymine?

Answer 5

Uracil (U)

Question 6

• The RNA chain produced by transcription
• It has a nucleotide sequence complementary to the DNA template.

Answer 6

TRANSCRIPT

Question 7

TRUE OR FALSE

• RNA strand does not remain hydrogen-bonded to DNA template
• RNA molecules are shorter than DNA molecules.

Answer 7

TRUE

Question 8

Where does RNA synthesis occur in eukaryotic cells?

• RNA then migrates to the cytoplasm for protein synthesis.

Answer 8

NUCLEUS

Question 9

A group of three ribonucleotide letters

Each of them specifies one amino acid.

Answer 9

CODON

Question 10

A given amino acid can be specified by more than one triplet codon

This is true for 18 of the 20 amino acids.

Answer 10

DEGENERATE

Question 11

Catalyze transcription by forming phosphodiester bonds

They link nucleotides together to form an RNA chain.

Answer 11

RNA polymerases

Question 12

Each transcribed segment of DNA

It typically carries the information of one gene.

Answer 12

transcription unit

Question 13

Assists RNA polymerase in recognizing promoters

This is crucial for initiating transcription.

Answer 13

sigma (σ) factor in bacterial transcription

Question 14

What are the two consensus sequences found in bacterial promoters?

Mutations in these regions can severely diminish transcription.

Answer 14

• TATAAT (Pribnow box, -10 region) * TTGACA (-35 region)

Question 15

The sequence of codons in a gene

Answer 15

COLINEAR

Question 16

The region of unpaired DNA during transcription

It is about 10 nucleotides long.

Answer 16

transcription bubble

Question 17

What structure does the newly formed RNA transcript sometimes fold into?

This is held together by hydrogen bonds.

Answer 17

Hairpin secondary structure

Question 18

Facilitates termination of transcription

It interacts with the growing RNA transcript.

Answer 18

rho (r) factor in bacterial transcription

Question 19

How many types of RNA polymerase are found in eukaryotic nuclei?

Answer 19

Three types: RNA polymerase I, II, and III

Question 20

• Take place on DNA packaged into nucleosomes
• This adds complexity compared to prokaryotic transcription.

Answer 20

eukaryotic transcription initiation

Question 21

What modification occurs at the 5’ end of a newly synthesized eukaryotic RNA molecule?

• This cap helps distinguish mRNAs from other RNA types

Answer 21

Addition of a 5’ methyl cap

Question 22

messenger RNA

code for proteins

Answer 22

mRNA

Question 23

ribosomal RNA

form the basic structure of the ribosome and catalyze protein synthesis

Answer 23

rRNA

Question 24

transfer RNA

central to protein synthesis as adaptors between mRNA and amino acids

Answer 24

tRNA

Question 25

small nuclear RNA function in a variety of nuclear processes; including the splicing of pre-mRNA

Answer 25

snRNA

Question 26

small nuclear RNA help to process and chemically modify rRNA

Answer 26

snoRNA

Question 27

microRNA regulate gene expression by blocking translation of specific mRNA and cause their degradation

Answer 27

miRNA

Question 28

small interfering RNA turn off gene expression by directing the degradation of selective mRNA and the establishment of compact chromatin structures

Answer 28

siRNA

Question 29

piwi-interacting RNA bind to piwi proteins protects the germ line from transposable elements

Answer 29

piRNA

Question 30

long noncoding RNA many of which serve as scaffolds regulate diverse cell processes, including X-chromosome inactivation

Answer 30

IncRNA