1.4 Nucleic Acids Flashcards
5’-to-3’
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.
Adenine (A)
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
antiparallel
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.
Chargaff’s rules
- 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.
Complementary base pairing
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
Complementary strand
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
Cytosine (C)
this pyrimidine pairs with guanine (G) via three hydrogen bonds,
Deoxyribonucleic acid (DNA)
a polymer of the four nucleotides A, C, G, and T, which are joined through a backbone of alternating phosphate and deoxyribose sugar residues
Deoxyribonucleotide
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.
Deoxyribose
the five-carbon sugar molecule that helps form the phosphate backbone of DNA molecules
Double helix
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.
Guanine (G)
a pyrimidine, and one of the nitrogenous bases that bind
Hairpin
daksndlkasndlas
Loop
lkdnas;kdn;aksnd
Nitrogenous base
A molecule that contains nitrogen and has the chemical properties of a base
Nucleic acid
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.
Nucleotide
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”).
Phosphate group
5’ end of each nucleiotide.
Phosphodiester linkage
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.
Purine
a base (such as adenine or guanine) that is a constituent of DNA or RNA.
Purine-pyrimidine pairs
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).
Pyrimidine
a class of organic compounds containing a six-member ring in which one of the carbon atoms has been replaced by a nitrogen atom.
Ribonucleic acid (RNA)
a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and DNA are nucleic acids.
Ribonucleotide
a nucleotide containing ribose as its pentose component
Ribose
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.
Ribozyme
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.
RNA world hypothesis
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
Stem
dfsdfsgsggshshsh
Sugar-phosphate backbone
the portion of the DNA double helix that provides structural support to the molecule
Template strand
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
Uracil (U)
a pyridine capable of bonding to adenine in RNA
