Nucleic Acids

Question 1

Nucleotide

Answer 1

The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and one or more phosphate groups

Question 2

Antiparallel

Answer 2

Referring to the arrangement of the sugar-phosphate backbones in a DNA double helix (they run in opposite 5’ - 3’ directions)

Question 3

DNA

Answer 3

Deoxyribonucleic acid.
A double-stranded, helical nucleic acid molecule, consisting of nucleotide monomers with a deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T); capable of being replicated and determining the inherited structure of a cell’s proteins

Question 4

RNA

Answer 4

Ribonucleic acid.
A type of nucleic acid consisting of a polynucleotide made up of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis, gene regulation, and as the genome of some viruses

Question 5

Polynucleotide

Answer 5

A polymer consisting of many nucleotide monomers in a chain. The nucleotides can be those of DNA or RN

Question 6

Purine

Answer 6

One of two types of nitrogenous bases found in nucleotides, characterised by a six-membered ring fused to a five-membered ring. Adenine (A) and guanine (G) are purines

Question 7

Pyrimidine

Answer 7

One of two types of nitrogenous bases found in nucleotides, characterised by a six-membered ring. Cytosine (C), thymine (T), and uracil (U) are pyrimidines

Question 8

Nucleoside

Answer 8

In a polynucleotide, each monomer has only one phosphate group. The portion of a nucleotide without any phosphate groups is called a nucleoside

Question 9

Nitrogenous base

Answer 9

Each nitrogenous base of a nucleotide has one or two rings that contain nitrogen atoms (called bases because the nitrogen atoms tend to take up H+).
Can be either a pyrimidine (cytosine C, thymine T, and uracil C). Or purine (adenine A, and guanine G).

Question 10

Double helix

Answer 10

DNA molecules have two polynucleotides, or “strands” that spiral around an imaginary axis, forming a double helix.

Question 11

DNA structure

Answer 11

Each DNA nucleotide consists of a nitrogenous base (T, A, C, or G), the sugar deoxyribose and a phosphate group.
Adenine pairs with thymine (A with T) and guanine pairs with cytosine (G with C)

Question 12

Pentose sugars

Answer 12

In DNA the sugar is deoxyribose. In RNA it is ribose. The only difference between these two sugars is that deoxyribose lacks an oxygen atom on the second carbon in the ring; hence the name deoxyribose.