CELS191 Lecture 9: Nucleus

These flashcards cover essential terms and concepts related to the nucleus and its components discussed in Lecture 9 of CELS191.

Nucleus

The most prominent organelle serving as the control center of the cell, contains most of the cell's genes.

Nuclear Envelope

A double membrane structure that surrounds the nucleus, composed of outer and inner membranes.

Nuclear Pore Complex

Channels made of proteins (nucleoporins) spanning the nuclear envelope that control molecular movement into and out of the nucleus.

Euchromatin

Less tightly packed DNA that is accessible for transcription; contains genes being actively used by the cell.

Heterochromatin

More tightly packed DNA that is electron-opaque and contains genes not being actively used by the cell.

Nucleolus

A non-membrane bound structure within the nucleus responsible for making ribosomal RNA and ribosomal subunits.

Ribosomes

Complexes made of ribosomal RNA and proteins that are involved in protein synthesis.

Transcription

The process of copying a segment of DNA into RNA.

Histones

Proteins around which DNA is tightly coiled to form nucleosomes and aid in DNA packaging.

Perinuclear Space

The space between the inner and outer membranes of the nuclear envelope.

Nuclear Lamina

A network of intermediate filaments lining the inner surface of the nuclear envelope that maintains the shape of the nucleus.

Nucleo-Cytoplasmic Exchange

The process by which molecules like RNA and proteins are transported between the nucleus and the cytoplasm.

Mitochondria

Organelles that contain additional genes that are separate from those found in the nucleus.

RNA (Ribonucleic Acid)

A molecule that carries genetic information from DNA to ribosomes for protein synthesis.

Chromosomes

Structures made of tightly coiled DNA that are visible during cell division.

Cytoplasm

The gel-like substance inside the cell membrane that contains cytosol, organelles, and other components.

Phospholipid Bilayer

A double layer of phospholipids that makes up the cell membrane and the nuclear envelope.

Nucleotide Polymer

The structural unit of DNA, which is made of nucleotides linked together in a long chain.

Transcriptional Machinery

Components involved in the process of transcription that need access to specific DNA regions.

Karyotype

A visual representation of the complete set of chromosomes in an individual, used for screening chromosomal abnormalities.