Biology Unit 1 Module 2

Question 1

Draw and Label the Structure of DNA and RNA

Question 2

What are nucleic acids?

Answer 2

Long thread-like molecules built up of monomers are called nucleotides. Nucleotides are joined together in a long chain.

Question 3

What are the two nucleic acids?

Answer 3

DNA- deoxyribonucleic acid
RNA- ribonucleic acid

Question 4

Where is DNA found and what is its function?

Answer 4

DNA can be found in the nucleus. It controls which enzymes and proteins are synthesized by cells

Question 5

Where is RNA found?

Answer 5

RNA can be found (on the ribosomes) in the cytoplasm

Question 6

Where else can nucleic acids be found?

Answer 6

The mitochondria and chloroplast

Question 7

What are the characteristics a nucleic acid DNA must have? (5)

Answer 7

1. Must be able to be replicated accurately. When the cell’s nucleus divides, it must pass on the exact gene copy of each molecule to the nucleus of its daughter cell.
2. The molecule must be metabolically stable to prevent imperfect copies which could lead to an increased risk of mutation.
3. Must be able to carry instruction and biological information.
4. Must provide means of transferring information into cell characteristics.
5. The amount of DNA remains constant for all cells within a species except gametes.

Question 8

What are nucleotides?

Answer 8

Monomers of nucleic acids.

Question 9

What are the components of a nucleotide?

Answer 9

A pentose sugar (ribose in RNA and deoxyribose in DNA), a nitrogenous base, and a phosphate group.

Question 10

What is the importance of the phosphate group?

Answer 10

It is chemically reactive which allows new groups to be added by condensation reactions. The phosphate group gives the nucleic acids their acidic nature.

Question 11

What is the makeup of a pentose sugar, its importance, and additionally what pentose sugar is used in DNA vs RNA?

Answer 11

This is a 5-carbon sugar which exists in a 5-sided ring form. It plays a role in the linkage of different nucleotides. The pentose sugar in DNA is deoxyribose and RNA is ribose.

Question 12

What is the nitrogenous base characterized into?

Answer 12

PURINE: Adenine (A) and Guanine (G) double rings composed of a 6-sided ring and a 5-sided ring

PYRIMIDINE: Uracil (U), Cytosine (C), and Thymine (T). single rings each composed of 6 sides

Question 13

How do we pair the bases in DNA?

Answer 13

GC, AT,

Question 14

How do we pair the bases in RNA?

Answer 14

GC, AU

Question 15

In which stage of the cell cycle does base paring occur and where?

Answer 15

It occurs during interphase in the cell’s nucleus.

Question 16

What are the two types of linkages in Nucleic Acids?

Answer 16

1. Phosphodiester Linkage
2. Complementary Base-Pairing

Question 17

What is a phosphodiester bond?
(What does it bond together, what is the base sequence, what type of bonding occurs and how does this bond physically impact the molecule)

Answer 17

This is a bond between the sugar group of one nucleotide and the phosphate group of another nucleotide. This bond occurs between the carbon 5 of one sugar and the carbon 3 of another sugar (base sequences 5’ to 3’). The type of bonding that occurs is covalent bonding. Finally, the bond determines the shape and the properties of the molecule produced.

Question 18

What is complementary base pairing? (What is the linkage between, what type of bond makes the possible, what is the base pairing like, and what shape is formed?

Answer 18

This is the linkage between nucleotides and is facilitated by hydrogen bonds between the base pairs. The bases projecting from the sugar-phosphate backbone of parallel strands of nucleotides which run in opposite directions are held by hydrogen bonds. This bond forms a 3-D configuration that stabilizes the molecule.

Question 19

What are the constraints of base pairing? (3)

Answer 19

The sugar-phosphate backbone of the two strands must run in opposite directions.

Base pairing normally occurs between particular pairs of bases.

One complete turn in the double helix strand is equal to 10 base pairs.