Molecular Biology Vocabulary

Flashcards of vocabulary terms and definitions from lecture notes

Double helix

The structure of DNA, resembling a twisted ladder.

Nucleic acids

Biological molecules (DNA or RNA) essential for all known forms of life.

Deoxyribose

A sugar derived from ribose by replacing a hydroxyl group with hydrogen.

Semi conservative method

DNA replication in which each new DNA molecule consists of one old strand and one new strand.

Replication forks

The point where the DNA strands separate during replication.

RNA primers

Short RNA sequences that initiate DNA synthesis.

DNA polymerase

An enzyme that synthesizes DNA molecules from deoxyribonucleotides.

Leading strand

The DNA strand that is synthesized continuously during replication.

Lagging strand

The DNA strand that is synthesized discontinuously during replication.

Okazaki fragment

Short DNA fragments synthesized on the lagging strand during replication.

DNA ligase

An enzyme that joins DNA fragments together.

Telomere

The ends of linear chromosomes that prevent DNA degradation and maintain stability.

Telomerase

An enzyme that adds DNA sequence repeats to the ends of chromosomes.

Mutation

A change in the DNA sequence.

Point mutation

A mutation affecting only one or a few nucleotides in a gene sequence.

Heritable mutations

Mutations that can be passed on to future generations.

Non-heritable mutations

Mutations that cannot be passed on to future generations.

Central dogma

The process by which information flows from DNA to RNA to protein.

Transcription

The process of synthesizing RNA from a DNA template.

Translation

The process of synthesizing a protein from an RNA template.

mRNA

Messenger RNA; carries genetic information from DNA to ribosomes.

rRNA

Ribosomal RNA; a component of ribosomes.

tRNA

Transfer RNA; carries amino acids to the ribosome during translation.

Transcription bubble

The region of unwound DNA during transcription.

RNA polymerase

An enzyme that synthesizes RNA from a DNA template.

Alternatively splicing

A process by which different combinations of exons are joined together, producing multiple mRNA transcripts from a single gene.

Genitic code

The set of rules by which information encoded in genetic material (DNA or RNA) is translated into proteins (amino acid sequences) by living cells.

Codon

A sequence of three nucleotides that together form a unit of genetic code in a DNA or RNA molecule.

Anti codon

A sequence of three nucleotides forming a unit of genetic code in a transfer RNA molecule, corresponding to a complementary codon in messenger RNA.

Elongation

The process by which the protein chain grows longer during translation.

Termination

The process by which translation ends.

Gene expression

The process by which information encoded in a gene is used to synthesize a functional gene product, such as a protein or RNA.