Chapter 22 - Nucleic Acids and Protein Synthesis Vocabulary

Flashcards for Chapter 22 Lecture Outline focusing on key vocabulary terms.

Nucleic acids

Unbranched polymers composed of repeating monomers called nucleotides. There are two types: DNA and RNA.

DNA (deoxyribonucleic acid)

Stores the genetic information of an organism and transmits that information from one generation to another.

RNA (ribonucleic acid)

Translates the genetic information contained in DNA into proteins needed for all cellular function.

Gene

The portion of the DNA molecule responsible for the synthesis of a single protein.

Nucleoside

Formed by joining the anomeric carbon of the monosaccharide with a N atom of the base. Named with the suffix “-idine” for pyrimidine bases and “-osine” for purine bases.

Nucleotide

Formed by adding a phosphate group to the 5′-OH of a nucleoside.

Phosphodiester linkage

Joins nucleotides together in nucleic acids (DNA and RNA).

Polynucleotide

Contains a backbone consisting of alternating sugar and phosphate groups. The identity and order of the bases distinguish one from another. Has one free phosphate group at the 5′ end and one free OH group at the 3′ end.

Replication

The process by which DNA makes a copy of itself when a cell divides.

Transcription

The ordered synthesis of RNA from DNA; the genetic information stored in DNA is passed onto RNA.

Translation

The synthesis of proteins from RNA; the genetic information determined the specific amino acid sequence of the protein.

Ribosomal RNA (rRNA)

Provides the site where polypeptides are assembled during protein synthesis in the ribosomes.

Messenger RNA (mRNA)

Carries the information from DNA (in the nucleus) to the ribosome.

Transfer RNA (tRNA)

Brings specific amino acids to the ribosomes for protein synthesis.

Codon

A sequence of three nucleotides (a triplet) that codes for a specific amino acid.

Anticodon

A sequence of three nucleotides in tRNA that is complementary to the codon in mRNA and identifies individual amino acids.

Mutation

A change in the nucleotide sequence in a molecule of DNA.

Point mutation

The substitution of one nucleotide for another.

Deletion mutation

Occurs when one or more nucleotides is/are lost from a DNA molecule.

Insertion mutation

Occurs when one or more nucleotides is/are added to a DNA molecule.

Recombinant DNA

Synthetic DNA that contains segments from more than one source.

Polymerase chain reaction (PCR)

Amplifies a specific portion of a DNA molecule, producing millions of exact copies.

Virus

An infectious agent consisting of a DNA or RNA molecule that is contained within a protein coating.

Retrovirus

A virus with an RNA core.

Reverse transcription

The process by which retroviruses synthesize viral DNA after invading a host.