Chapter 5: Nucleic Acids (Transcription)

Question 1

states that in cells, the flow of genetic information contained in DNA is a one-way street that leads from DNA to RNA to protein

Answer 1

central dogma

Question 2

no. of base pairs of DNA in humans

Answer 2

50 million to 300 million

Question 3

no. of nucleotides in RNA

Answer 3

75 to few thousands nucleotides

Question 4

similarities between DNA and RNA

Answer 4

• nucleic acids
• composed of nucleotides
• sugar-phosphate backbone
• nitrogenous bases

Question 5

Types of RNA

Answer 5

1. heterogenous nuclear RNA (hnRNA)
2. messenger RNA (mRNA)
3. small nuclear RNA (snRNA)
4. ribosomal RNA (rRNA)
5. transfer RNA (tRNA)

Question 6

RNA formed directly by DNA transcription

Answer 6

heterogeneous nuclear RNA (hnRNA)

Question 7

converts the hnRNA to mRNA

Answer 7

post-transcription processing

Question 8

RNA that carries instructions for protein synthesis to the sites for protein synthesis

Answer 8

messenger RNA (mRNA)

Question 9

• RNA that facilitates the conversion of hnRNA to mRNA
• contains 100 to 200 nucleotides

Answer 9

small nuclear RNA (snRNA)

Question 10

small nuclear RNA (snRNA) contains how many nucleotides

Answer 10

100 to 200

Question 11

• RNA that combines with specific proteins to form ribosomes, the physical site for protein synthesis
• has no informational function

Answer 11

ribosomal RNA (rRNA)

Question 12

• RNA that delivers amino acids to sites for protein synthesis
• smallest of the RNAs, possessing only 75 to 90 nucleotide units

Answer 12

transfer RNA (tRNA)

Question 13

transfer RNA (tRNA) contains how many nucleotides

Answer 13

only 75 to 90

Question 14

any part of a gene that will form part of the final mature RNA

Answer 14

exon

Question 15

noncoding sections of an RNA transcript, or the DNA encoding it, that are spliced out before the RNA molecule is translated into a protein

Answer 15

Introns

Question 16

• biological process where a newly synthesized pre-mRNA transcript is processed and transformed into mRNA
• involves the removing of non-coding regions of RNA (introns) and the joining of the coding regions (exons)

Answer 16

RNA splicing

Question 17

in RNA splicing, introns are removed and exons are covalently joined to one another as part of generating __ __

Answer 17

mature RNA

Question 18

entire set of exons constitute __

Answer 18

exome

Question 19

RNA molecules differ from DNA molecules in that they are

Answer 19

single stranded

Question 20

m in the designation mRNA stands for

Answer 20

messenger

Question 21

t in the designation tRNA stands for

Answer 21

transfer

Question 22

involved in the transcription phase of protein synthesis

Answer 22

hnRNA

Question 23

process by which DNA directs the syntheis of hnRNA/mRNA molecules that carry the coded information needed for protein synthesis

Answer 23

transcription

Question 24

messenger RNA production via transcription is actually a two step in which

Answer 24

1. hnRNA molecules is initally produced
2. edited to yield desired mRNA molecule

Question 25

Transcription steps

Answer 25

1. initiation 2. elongation/synthesis of RNA transript 3. termination

Question 26

binding of RNA polymerase to a specific nucleotide sequence, the promoter, at the beginning of a gene

Answer 26

initiation

Question 27

transcription produces a complementary copy of only __ of the two strands of DNA

Answer 27

one

Question 28

begins as the RNA polymerase "reads" the DNA template strand and catalyze the polymerization of a complementary RNA copy

Answer 28

chain elongation

Question 29

during RNA synthesis, how many base pairs of DNA template strand are exposed at a time

Answer 29

10 base pairs

Question 30

is involved in the linkage of ribonucleotides, one by one, to the growing hnRNA molecule

Answer 30

RNA polymerase

Question 31

direction of RNA polymerase movement

Answer 31

5' to 3'

Question 32

the RNA polymerase finds a termination sequence at the end of the gene

Answer 32

termination

Question 33

in eukaryotes, transcription produces a primary transcript that must undergo ______ before it is exported out of the nucleus for translatio in the cytoplasm

Answer 33

post-transcriptional modification

Question 33

Three post transcriptional modification

Answer 33

1. 5'-methylated cap structure 2. poly(A) tail 3. RNA splicing (eukaryotes)

Question 33

required for efficient translation of the final mature mRNA

Answer 33

5'-methylated cap structure

Question 34

protects the 3' end of the mRNA from enzymatic degradation and thus prolongs the lifetime of the mRNA

Answer 34

poly(A) tail

Question 35

removal of portions of the primary transcript that are not protein coding

Answer 35

RNA splicing (eukaryotes)

Question 36

mark the boundaries of the introns

Answer 36

signals

Question 37

bacterial genes are __; all the nucleotide sequences of the gener are found in the mRNA

Answer 37

continuous

Question 38

contains protein coding exons, and noncoding introns

Answer 38

beta-globin gene

Question 39

required its assistance during recognition of the splice boundaries and stabilization of the splicing complex

Answer 39

spliceosomes

Question 40

what are spliceosomes made out of

Answer 40

small nuclear ribonucleoproteins

Question 41

catalytically active RNA molecules or RNA–protein complexes, in which solely the RNA provides catalytic activity

Answer 41

Ribozymes

Question 42

process by which several different proteins that are variations of a basic structural motif can be produced from a single gene

Answer 42

alternative splicing

Question 43

machinery that bridges the genome-proteome gap

Answer 43

spliceosome

Question 44

what occurs during the transcription phase of protein synthesis

Answer 44

partial unwinding of DNA double helix

Question 45

what is the complementary hnRNA base sequence produced from DNA base sequence 5' C-T-A-T-A-C 3'

Answer 45

3' G-A-U-A-U-G 5'

Question 46

location in DNA strand carrying information needed for synthesis of a specific hnRNA molecule

Answer 46

gene

Question 47

types of RNA contains introns and exons

Answer 47

hnRNA

Question 48

proposed that there are only four letters in the DNA alphabet (A, T, G, C)

Answer 48

George Gamow

Question 49

code that is sufficient to encode the twenty amino acids but not too excessive

Answer 49

4^3 = 64 combinations

Question 50

sequence of amino acids in a mRNA that determines the amino acid order for the protein

Answer 50

genetic code

Question 51

triplet in mRNA that translates to a specific amino acid

Answer 51

codon

Question 52

- trinucleotide sequence located at one end of a transfer RNA (tRNA) molecule - complementary to a corresponding codon in a messenger RNA (mRNA) sequence

Answer 52

Anticodon

Question 53

three codons that are stop signals for protein synthesis

Answer 53

- UAA - UGA - UAG

Question 53

- start codon - codes for amino acid methionine if found elsewhere

Answer 53

AUG