Unit (12) Molecules of Life: Nucleic Acids

Question 1

What are the two kinds of nucleic acid

Answer 1

RNA-ribonucleic acid and DNA-deoxyribonucleic acid

Question 2

Both RNA and DNA are large polymers containing repeating structural units or monomers, called…

Answer 2

Nucleotides

Question 3

What are the three units that compose a nucleotide?

Answer 3

Organic Base, a sugar, and a phosphate

Question 4

The organic bases found in nucleic acids are derivatives of what?

Answer 4

Pyrimidine, or purine

Question 5

The three pyrimidine derivatives found in nucleic acids are?

Answer 5

Cytosine (C), Thymine (T), and Uracil (U)

Question 6

The two purine derivatives found in nucleic acids are?

Answer 6

Adenine (A), and Guanine (G)

Question 7

Adenine, Guanine, and Cytosine are found?

Answer 7

In both RNA and DNA

Question 8

Thymine is found only in?

Answer 8

DNA

Question 9

Uracil is found only in?

Answer 9

RNA

Question 10

The five carbon sugar in RNA is called what?

Answer 10

Ribose

Question 11

The five carbon sugar in DNA is called what?

Answer 11

2’-deoxyribose

Question 12

The only difference between the two sugars is found on carbon 2’, what is the difference

Answer 12

The ribose carbon 2’ has an OH group, while the 2’ carbon for deoxyribose has only H- deoxy-means no oxygen

Question 13

When ribose or 2’-deoxyribose is combined with a purine or a pyrimidine base, what is formed?

Answer 13

A nucleoside

Question 14

A nucleoside is basically what?

Answer 14

A nucleotide that is missing the phosphate portion

Question 15

What are the three classes of RNA?

Answer 15

mRNA-messenger RNA
tRNA-transfer RNA
rRNA- ribosomal RNA

Question 16

What does mRNA do?

Answer 16

carries genetic information from DNA to the ribosomes and serves as a template for protein synthesis

Question 17

What does tRNA do?

Answer 17

delivers individual amino acids to the site of protein synthesis

Question 18

What does rRNA do?

Answer 18

combines with a series of proteins to form ribosomes, the physical site of active protein synthesis

Question 19

What is GENE EXPRESSION?

Answer 19

is the activation (turning on) of a gene to produce a specific protein. Two steps are involved, transcription and translation

Question 20

What is transcription?

Answer 20

Transcription is the process of mRNA synthesis from a single stranded DNA tmplate

Question 21

What is the name of the enzyme that catalyzes transcription?

Answer 21

RNA polymerase

Question 22

On mRNA, (A)-Adenine pairs with what?

Answer 22

U- Uracil

Question 23

The RNA produced from gene activation in transcription is called what?

Answer 23

pre-mRNA

Question 24

What are the two segments contained in the pre-mRNA?

Answer 24

Exon-coded for amino acids

Intron- carries no codes for amino acids

Question 25

What is an Exon?

Answer 25

a gene segment that conveys (codes for) genetic information

Question 26

What is an Intron?

Answer 26

a gene segment that does not convey (code for) genetic information

Question 27

What is Splicing?

Answer 27

the process of removing the introns from the pre-mRNA molecule and joining (splicing) the remaining exons together to form a mRNA molecule

Question 28

How is the mRNA sequence read?

Answer 28

three bases (triplet) at a time and each segment of threes bases is called a CODON.

Question 29

What does each codon specify?

Answer 29

A particular amino acid in the primary structure of the protein (its sequence of amino acids)

Question 30

How many different codons are used to specify amino acids?

Answer 30

61, plus three addition “stop” signals

Question 31

What is the genetic code?

Answer 31

the assignment of the 64 mRNA codons to specific amino acids (or stop signals)

Question 32

The process of protein synthesis from mRNA is called?

Answer 32

Translation

Question 33

What is an Anticodon?

Answer 33

A sequence of three nucleotides on tRNA, complementary to the codon on mRNA