Lecture 8: DNA, Chromosomes, and the Nucleus (Bio 211)

A collection of vocabulary flashcards focusing on key concepts related to DNA, chromosomes, and nuclear processes.

DNA

A molecule that carries the genetic instructions for living organisms.

Nucleus

The membrane-bound organelle in eukaryotic cells that contains the chromosomes.

Chromatin

A complex of DNA and proteins that forms chromosomes within the nucleus.

Nucleotide

The basic building block of nucleic acids, composed of a five-carbon sugar, a phosphate group, and a nitrogenous base.

Denaturation

The process of separating the two strands of DNA by disrupting the hydrogen bonds between bases.

Renaturation

The process of re-binding DNA strands to form a double helix after denaturation.

Tm (melting temperature)

The temperature at which half of the DNA strands are denatured.

Nucleosome

A structural unit of chromatin, consisting of DNA wrapped around a core of histone proteins.

GC content

The percentage of guanine and cytosine bases in a DNA molecule, which affects the melting temperature.

Euchromatin

Less condensed form of chromatin that is actively involved in transcription.

Heterochromatin

Highly condensed form of chromatin that is generally not active in transcription.

Nuclear Pore Complex

A structure that regulates the transport of materials into and out of the nucleus.

Nuclear localization signal (NLS)

A short amino acid sequence that marks a protein for import into the nucleus.

Nuclear export signal (NES)

A signal that directs proteins to be transported out of the nucleus.

Histone

A type of protein that helps package DNA into nucleosomes.

Acetylation

The addition of an acetyl group to lysine residues in histones, affecting DNA packing.

Methylation

The addition of a methyl group to DNA or histones, which can influence gene expression.

Phosphorylation

The addition of a phosphate group to histones, which can also alter nucleosome interactions with DNA.

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process of synthesizing proteins from mRNA.

Gene

A segment of DNA that contains instructions for producing a specific protein or functional RNA.