1.4 Nucleic Acids

Question 1

5’-to-3’

Answer 1

5’ - 3’ direction refers to the orientation of nucleotides of a single strand of DNA or RNA. … The phosphate group attached to the 5’ end of one nucleotide and the hydroxyl group at the 3’ end of another nucleotide have the potential to form phosphodiester bonds and hence link adjacent nucleotides.

Question 2

Adenine (A)

Answer 2

this base pairs only with uracil during the synthesis of an RNA strand from a DNA template (transcription); this base pairs only with thymine during DNA replication

Question 3

antiparallel

Answer 3

a term used to describe the opposite orientations of the two strands of a DNA double helix; the 5’ end of one strand aligns with the 3’ end of the other strand.

Question 4

Chargaff’s rules

Answer 4

1. the number of guanine units approximately equals the number of cytosine units and the number of adenine units approximately equals the number of thymine units. 2. is that the composition of DNA varied from one species to another.

The base paring rules state that A always pairs with T and G always pairs with C.

Question 5

Complementary base pairing

Answer 5

describes the manner in which the nitrogenous bases of the DNA molecules align with each other. Complementary base pairings are also responsible for the double-helix structure of DNA

Question 6

Complementary strand

Answer 6

either of the two chains that make up a double helix of DNA, with corresponding positions on the two chains being composed of a pair of complementary bases

Question 7

Cytosine (C)

Answer 7

this pyrimidine pairs with guanine (G) via three hydrogen bonds,

Question 8

Deoxyribonucleic acid (DNA)

Answer 8

a polymer of the four nucleotides A, C, G, and T, which are joined through a backbone of alternating phosphate and deoxyribose sugar residues

Question 9

Deoxyribonucleotide

Answer 9

a nucleotide that contains deoxyribose. They are the monomeric units of the informational biopolymer, deoxyribonucleic acid (DNA). Each deoxyribonucleotide comprises three parts: a deoxyribose sugar (monosaccharide), a nitrogenous base, and one phosphoryl group.

Question 10

Deoxyribose

Answer 10

the five-carbon sugar molecule that helps form the phosphate backbone of DNA molecules

Question 11

Double helix

Answer 11

the description of the structure of a DNA molecule. A DNA molecule consists of two strands that wind around each other like a twisted ladder. Each strand has a backbone made of alternating groups of sugar (deoxyribose) and phosphate groups.

Question 12

Guanine (G)

Answer 12

a pyrimidine, and one of the nitrogenous bases that bind

Question 13

Hairpin

Answer 13

daksndlkasndlas

Question 14

Loop

Answer 14

lkdnas;kdn;aksnd

Question 15

Nitrogenous base

Answer 15

A molecule that contains nitrogen and has the chemical properties of a base

Question 16

Nucleic acid

Answer 16

description: polymers made up of monomers called nucleotides
function: store, transmit, and help express hereditary information. There are two types of nucleic acids: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
formation: when nucleotides polymerize via a condensation reaction that results in the formation of a phosphodiester bond. Nucleic acids grow in the 5’-to-3’ direction, giving rise to an overall polarity.

Question 17

Nucleotide

Answer 17

s made up of a sugar (ribose for nucleotides in RNA, deoxyribose for nucleotides in DNA), a phosphate group, and a nitrogenous base. The purines have a double ring structure with a six-membered ring fused to a five-membered ring. Pyrimidines are smaller with a single six-membered ring structure. The carbon atoms of the five-carbon sugar are numbered 1’, 2’, 3’, 4’, and 5’ (1’ is read as “one prime”).

Question 18

Phosphate group

Answer 18

5’ end of each nucleiotide.

Question 19

Phosphodiester linkage

Answer 19

the linkage between the 3’ carbon atom of one sugar molecule and the 5’ carbon atom of another, deoxyribose in DNA and ribose in RNA.

Question 20

Purine

Answer 20

a base (such as adenine or guanine) that is a constituent of DNA or RNA.

Question 21

Purine-pyrimidine pairs

Answer 21

Purines and pyrimidines are base pairs. The two most common base pairs are A-T and C-G. These nucleotides are complementary —their shape allows them to bond together with hydrogen bonds. In the C-G pair, the purine (guanine) has three binding sites, and so does the pyrimidine (cytosine).

Question 22

Pyrimidine

Answer 22

a class of organic compounds containing a six-member ring in which one of the carbon atoms has been replaced by a nitrogen atom.

Question 23

Ribonucleic acid (RNA)

Answer 23

a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and DNA are nucleic acids.

Question 24

Ribonucleotide

Answer 24

a nucleotide containing ribose as its pentose component

Question 25

Ribose

Answer 25

a five-carbon sugar found in RNA (ribonucleic acid), where it alternates with phosphate groups to form the “backbone” of the RNA polymer and binds to nitrogenous bases.

Question 26

Ribozyme

Answer 26

a ribonucleic acid (RNA) enzyme that catalyzes a chemical reaction. The ribozyme catalyzes specific reactions in a similar way to that of protein enzymes. Also called catalytic RNA, ribozymes are found in the ribosome where they join amino acids together to form protein chains.

Question 27

RNA world hypothesis

Answer 27

this hypothesis suggests that life on Earth began with a simple RNA molecule that could copy itself. The RNA world hypothesis suggests that life on Earth began with a simple RNA molecule that could copy itself without help from other molecules. DNA, RNA, and proteins are central to life on Earth

Question 28

Stem

Answer 28

dfsdfsgsggshshsh

Question 29

Sugar-phosphate backbone

Answer 29

the portion of the DNA double helix that provides structural support to the molecule

Question 30

Template strand

Answer 30

The DNA strand that mRNA is built from is called the template strand because it serves as a template for transcription. The template strand runs in a 3’ to 5’ direction

Question 31

Uracil (U)

Answer 31

a pyridine capable of bonding to adenine in RNA