Ch 3 Nucleic Acids

Question 1

What is responsible for most differences between organisms?

Answer 1

Gene variation

98.8% sequence identity

Question 2

Where is DNA located in eukaryotic cells?

Answer 2

Nucleus

Question 3

What is the structure of DNA in eukaryotes?

Answer 3

Linear and contained within chromosomes

Question 4

How is DNA structured in prokaryotes?

Answer 4

Circular

Question 5

What are genes composed of?

Answer 5

DNA

Question 6

Do all genes coded by an organism’s DNA express as protein?

Answer 6

No, some code for functional RNA molecules

Question 7

What are nucleic acids made of?

Answer 7

Polymers of nucleotides

Question 8

What are the components of a nucleotide?

Answer 8

• A nitrogen base
• A monosaccharide (ribose)
• At least one phosphate

Question 9

What distinguishes nucleosides from nucleotides?

Answer 9

Nucleosides consist of a nitrogen base and ribose sugar; nucleotides include a phosphate group.

Question 10

What is the general structure of DNA?

Answer 10

A double helix

Question 11

What type of bonds link nucleotides together?

Answer 11

Phosphodiester bonds

Question 12

What does the central dogma explain?

Answer 12

How cells express genetic information

Question 13

What are the three main processes involved in the central dogma?

Answer 13

• DNA replication
• Transcription
• Translation

Question 14

What is the function of transcription?

Answer 14

RNA synthesis

Question 15

What does translation produce?

Answer 15

Proteins

Question 16

Which bases pair together in DNA?

Answer 16

• A pairs with T
• C pairs with G

Question 17

What sugar is found in RNA?

Answer 17

Ribose

Question 18

What sugar is found in DNA?

Answer 18

Deoxyribose

Question 19

What are the components of chromatin?

Answer 19

• DNA
• Histones

Question 20

What is supercoiling in DNA?

Answer 20

The three-dimensional arrangement of all atoms of DNA

Question 21

What type of proteins are histones?

Answer 21

Positively charged proteins rich in lysine and arginine

Question 22

What is a nucleosome?

Answer 22

A unit of DNA wound around histone proteins

Question 23

What is the average length of the haploid human genome?

Answer 23

~3 billion nucleotides long

Question 24

What is the structure formed by DNA wrapped around histones?

Answer 24

Chromatin

Question 25

How do you read the sequence of bases in nucleic acids?

Answer 25

From 5′ to 3′

Question 26

What is the significance of Rosalind Franklin in DNA research?

Answer 26

She contributed to the discovery of DNA's structure through X-ray diffraction.

Question 27

What is the difference between coding and noncoding portions of the genome?

Answer 27

Coding portions are translated into proteins; noncoding portions do not code for proteins.

Question 28

What can a mutated gene cause?

Answer 28

Disease, such as sickle cell disease

Question 29

True or False: DNA contains thymine while RNA contains uracil.

Answer 29

True

Question 30

Fill in the blank: The sugar atoms in nucleotides are numbered with _______ to distinguish them from the attached bases.

Answer 30

primes

Question 31

What is the role of coenzyme A?

Answer 31

Capturing free energy

Question 32

What are the three structural forms of DNA?

Answer 32

* B-DNA * A-DNA * Z-DNA

Question 33

What is the arrangement of all atoms of the DNA called?

Answer 33

Supercoiling ## Footnote Supercoiling refers to the overwinding or underwinding of the DNA strand.

Question 34

What proteins are involved in the supercoiling of eukaryotic DNA?

Answer 34

Histones ## Footnote Histones are positively charged proteins that help package DNA into chromatin.

Question 35

What are histones rich in?

Answer 35

Basic amino acids Lys and Arg ## Footnote These amino acids contribute to the positive charge of histones.

Question 36

What is chromatin?

Answer 36

A complex of DNA wound around histones in a bead-like structure ## Footnote Chromatin plays a crucial role in DNA packaging and regulation.

Question 37

What is the structure of chromatin often described as?

Answer 37

Beads on a string ## Footnote This description refers to the nucleosome structure formed by DNA wrapped around histones.

Question 38

What is each 'bead' in the chromatin structure called?

Answer 38

Nucleosome ## Footnote Nucleosomes are the fundamental units of chromatin.

Question 39

What does the stability of a DNA double helix depend mostly on?

Answer 39

Stacking interactions ## Footnote Stacking interactions refer to the interactions between adjacent base pairs in the DNA strand.

Question 40

True or False: DNA can denature (unfold).

Answer 40

True ## Footnote Denaturation refers to the separation of the two strands of DNA.

Question 41

True or False: DNA can renature (refold, anneal).

Answer 41

True ## Footnote Renaturation is the process where separated DNA strands rejoin.