DNA Replication & Gene Expression

These flashcards cover key vocabulary terms and definitions related to DNA replication, gene expression, mutations, and cellular processes as outlined in the lecture notes.

DNA Replication

The process of copying the DNA molecule to produce two identical DNA strands.

Transcription

The process by which mRNA is synthesized from a DNA template.

Translation

The process of synthesizing proteins from mRNA at the ribosome.

Mutations

Permanent changes in the DNA sequence that can result from errors in DNA replication or environmental factors.

Allele

Different forms of a gene that can exist at a specific locus on a chromosome.

Sickle Cell Trait

A genetic condition where an individual has one normal hemoglobin allele and one mutated allele.

Chromatin

The complex of DNA and protein found in the nucleus, consisting of nucleosomes.

Codon

A three-nucleotide sequence on mRNA that codes for a specific amino acid.

Intron

A non-coding segment of a gene that is removed during mRNA processing.

Exon

The coding segment of a gene that remains in the mature mRNA after processing.

Antiparallel

Referring to the orientation of the two strands of the DNA double helix running in opposite directions.

Polypeptide

A chain of amino acids linked by peptide bonds that forms a protein.

tRNA

Transfer RNA that carries amino acids to the ribosome during protein synthesis.

Ribosome

A cellular structure where protein synthesis occurs, composed of rRNA and proteins.

Pretranscriptional control

Regulation of gene expression occurring before transcription, affecting chromatin structure.

Posttranscriptional control

Regulation of gene expression occurring after transcription, involving mRNA processing.

Frameshift mutation

A genetic mutation caused by insertions or deletions that shift the reading frame of codons.

Point mutation

A mutation affecting a single nucleotide, which can lead to a change in a single amino acid.

Double helix

The structure of DNA, consisting of two strands twisted around each other.

Semiconservative replication

The method of DNA replication where each new double helix contains one original and one newly synthesized strand.