Molecular Biology: DNA, RNA, and Genetic Processes

Nucleic acids

Composed of nucleotides, essential for genetic information.

Phosphate groups

Part of nucleotides, links nucleic acids together.

Pentose sugars

Five-carbon sugars in DNA and RNA nucleotides.

Deoxyribose

Sugar in DNA, lacks one oxygen atom.

Ribose

Sugar in RNA, contains one more oxygen than deoxyribose.

Nitrogenous bases

A, T, C, G, and U; building blocks of nucleic acids.

Purines

Adenine and guanine, two-ring nitrogenous bases.

Pyrimidines

Cytosine, thymine, and uracil; single-ring bases.

Transformation

Genetic alteration of a cell by external DNA.

Griffith's experiment

Demonstrated transformation using Streptococcus pneumoniae.

Avery's experiment

Identified DNA as the transforming agent.

Bacteriophages

Viruses that infect bacteria, used in Hershey-Chase experiment.

Chargaff's Rule

A=T and G=C in DNA molecules.

Double helix

Three-dimensional structure of DNA, twisted ladder shape.

DNA replication

Process of copying DNA during cell division.

Helicase

Enzyme that unwinds and separates DNA strands.

DNA polymerase

Enzyme that synthesizes new DNA strands.

Leading strand

Continuously synthesized DNA strand during replication.

Lagging strand

Discontinuously synthesized DNA strand with Okazaki fragments.

DNA ligase

Enzyme that joins Okazaki fragments together.

Central Dogma

Flow of genetic information: DNA to RNA to Protein.

Transcription

Synthesis of RNA from a DNA template.

Translation

Synthesis of protein from mRNA at ribosomes.

Codon

Sequence of three nucleotides coding for an amino acid.

Point mutations

Alterations at a specific base in DNA.

Frame shift mutations

Mutations that shift the reading frame of codons.