Chapter 3.3: Nucleic Acids: Information Molecules

Question 1

Define deoxyribonucleic acid (DNA)

Answer 1

the genetic material of all organisms; composed of two complementary chains of nucleotides wound in double helix

Question 2

What is the genetic material of all organisms; composed of two complementary chains of nucleotides wound in double helix?

Answer 2

deoxyribonucleic acid (DNA)

Question 3

Define ribonucleic acid (RNA)

Answer 3

a class of nucleic acids characterized by the presence of the sugar ribose and the pyrimidine uracil

Question 4

What is a class of nucleic acids characterized by the presence of the sugar ribose and the pyrimidine uracil?

Answer 4

ribonucleic acid (RNA)

Question 5

Define messenger RNA (mRNA)

Answer 5

the RNA transcribed from structural genes; RNA molecules complementary to a portion of one strand of DNA, which are translated by the ribosomes to form proteins

Question 6

What is the RNA transcribed from structural genes; RNA molecules complementary to a portion of one strand of DNA, which are translated by the ribosomes to form proteins?

Answer 6

messenger RNA (mRNA)

Question 7

Define nucleotide

Answer 7

a single unit of nucleic acid, composed of a phosphate, a 5-carbon sugar (either ribose or deoxyribose), and a purine or a pyrimidine

Question 8

What is a single unit of nucleic acid, composed of a phosphate, a 5-carbon sugar (either ribose or deoxyribose), and a purine or a pyrimidine?

Answer 8

nucleotide

Question 9

Define purines

Answer 9

large double-ring molecules that are each found in both DNA and RNA

Question 10

What are the two purines?

Answer 10

adenine and guanine

Question 11

Define pyrimidines

Answer 11

single-ring molecules

Question 12

What are the three pyrimidines?

Answer 12

 Cytosine (C, in both DNA and RNA), thymine (T, in DNA only), and uracil (U, in RNA only)

Question 13

How are DNA molecules organized in eukaryotes?

Answer 13

two chains wrapped about each other in a long linear molecule

Question 14

How are DNA molecules organized in prokaryotes?

Answer 14

circular molecule

Question 15

Define double helix

Answer 15

the structure of DNA, in which two complementary polynucleoide strands coil around a common helical axis

Question 16

What is the structure of DNA, in which two complementary polynucleoide strands coil around a common helical axis?

Answer 16

double helix

Question 17

Define complementary in terms of DNA

Answer 17

describes genetic information in which each nucleotide base has a complementary partner with which it forms a base-pair

Question 18

What describes genetic information in which each nucleotide base has a complementary partner with which it forms a base-pair?

Answer 18

complemetary

Question 19

What does adenine pair with?

Answer 19

thymine (DNA) and uracil (RNA)

Question 20

What does cytosine pair with?

Answer 20

guanine

Question 21

What does thymine pair with?

Answer 21

adenine

Question 22

What does uracil pair with?

Answer 22

adenine

Question 23

What does guanine pair with?

Answer 23

cytosine

Question 24

How many hydrogen bonds between adenine and thymine/uracil?

Answer 24

2 hydrogen bonds

Question 25

How many hydrogen bonds between cytosine and guanine?

Answer 25

3 hydrogen bonds

Question 26

Define ribosomal RNA (rRNA)

Answer 26

)- a class of RNA molecules found, together with characteristic proteins, in ribosomes; transcribed from the DNA of the nucleus

Question 27

What is )- a class of RNA molecules found, together with characteristic proteins, in ribosomes; transcribed from the DNA of the nucleus?

Answer 27

ribosomal RNA (rRNA)

Question 28

Define transfer RNA (tRNA)

Answer 28

a class of small RNAs (about 80 nucleotides) with two functional sites; at one site, an activating enzyme” adds a specific amino acid, while the other site carries the nucleotide triplet (anticodon) specific for that amino acid

Question 29

WHat is a class of small RNAs (about 80 nucleotides) with two functional sites; at one site, an activating enzyme” adds a specific amino acid, while the other site carries the nucleotide triplet (anticodon) specific for that amino acid?

Answer 29

transfer RNA (tRNA)

Question 30

Define adenosine triphosphate (ATP)

Answer 30

a nucleotide consisting of adenine, ribose sugar, and three phosphate groups; ATP is the energy currency of cellular metabolism in all organisms

Question 31

What is a nucleotide consisting of adenine, ribose sugar, and three phosphate groups; ATP is the energy currency of cellular metabolism in all organisms?

Answer 31

o Adenosine Triphosphate (ATP)

Question 32

Define o Nicotinamide Adenine Dinucleotide (NAD+)

Answer 32

a molecule that becomes reduced (to NADH) as it carries high-energy electrons from oxidized molecules and delivers them to ATP-producing pathways in the cell

Question 33

What is a molecule that becomes reduced (to NADH) as it carries high-energy electrons from oxidized molecules and delivers them to ATP-producing pathways in the cell?

Answer 33

o Nicotinamide Adenine Dinucleotide (NAD+)

Question 34

Define o Flavin Adenine Dinucleotide (FAD, FADH2)

Answer 34

a cofactor that acts as a soluble (not membrane-bound) electron carrier (can be reversibly oxidized and reduced)

Question 35

What is a cofactor that acts as a soluble (not membrane-bound) electron carrier (can be reversibly oxidized and reduced)?

Answer 35

o Flavin Adenine Dinucleotide (FAD, FADH2)