Chapter 3.3: Nucleic Acids Are Informational Macromolecules

Flashcards from Chapter 3.3 of Principles of Life, 3rd Edition.

Nucleic acids

Polymers that store and express genetic information via nucleotide monomers, grouped into DNA (with deoxyribose) and RNA (with ribose)

• DNA encodes for RNA, which encodes for protein types

Nucleotide

A single unit of a nucleic acid, made of a monosaccharide, a nitrogen-containing base (linked to the 1’ carbon), and one to three phosphate groups (linked to the 5’ carbon)

• Can be joined in oligonucleotides for basic regulation as RNA (3 to 20 monomers) or polynucleotides for heredity in DNA (hundreds of millions of monomers)

Base

Nitrogen-containing molecules that form the genetic code for DNA and RNA, classified as pyrimidines (single rings) or purines (double rings)

• Linked to the 1’ carbon

Nucleoside

A nitrogenous base and ribose without a phosphate group

Phosphodiester bond

This is formed to create the “sides” in the sugar-phosphate bond, where the 3’ carbon atom on the previous nucleotide is linked to the triphosphate on the next 5’ carbon atom

• Requires more than one phosphate due to an increase in free energy

Complimentary base pairing

When two nitrogenous bases in DNA or RNA pair with their complimentary parts through hydrogen bonds

• These bonds across millions of bases collectively create an attraction that is strong enough to remain together but can be separated with some energy

• Required for transcription and translation, which are performed in opposite direction

• In DNA, this is done with cytosine, thymine, adenine, and guanine; in RNA, this is done with uracil instead of thymine

Deoxyribonucleic acid (DNA)

A double-stranded molecule with informational and complimentary base pairs in the middle, twisting into a helical structure

• The expression of this is determined by its function and position in the body despite each cell containing all of this molecule’s instructions

Ribonucleic acid (RNA)

A single-stranded molecule that can fold back, stabilized by complimentary base pairing

• Created as a result of transcription from DNA to signal for protein production in translation in smaller groups

DNA replication

The process where DNA is copied onto new DNA molecules for transmission to daughter cells and offspring