DNA Packaging

Vocabulary flashcards related to DNA packaging.

Prokaryotic Cells

Cells without a nucleus that divide by fission and typically have one circular chromosome.

Eukaryotic Cells

Cells that divide by mitosis or meiosis, usually have many chromosomes, and contain a nucleus which must replicate and divide during cell division.

Nucleus

The largest organelle in the cell containing most of the cell’s genetic material (DNA) where replication and the first steps in decoding take place.

Nuclear Pores

Structures that transport molecules across the nuclear envelope, including RNA and ribosomal proteins out, and proteins, carbohydrates, signaling molecules, and lipids in.

Chromosomes

Thread-like structures in the nucleus where DNA molecules are packaged, each having a constriction point called the centromere.

Centromere

The constriction point on a chromosome that divides it into two sections or arms (p arm and q arm).

Histones

Proteins that compact chromosomal DNA into the microscopic space of the eukaryotic nucleus.

Chromatin

The DNA-protein complex resulting from histones compacting chromosomal DNA.

Nucleosomes

The basic repeating structural and functional unit of chromatin, containing nine histone proteins and about 166 base pairs of DNA.

30-nm fiber

A fiber that chromatin is further coiled into which is even shorter and thicker than the nucleosome.

Heterochromatin

Condensed form of chromatin.

Euchromatin

Extended form of chromatin.

Nuclear Lamina

A dense fibrillar network inside the nucleus of eukaryotic cells, composed of intermediate filament proteins; interacts with the nuclear membrane and provides structural support.

Nucleolus

The largest structure in the nucleus of eukaryotic cells, where ribosomal RNA (rRNA) is transcribed and ribosomes are assembled.

Ribosomes

Complex molecular machines that catalyze protein synthesis, translating genetic code from messenger RNA (mRNA) into an amino acid sequence.

Endoplasmic Reticulum (ER)

An extensive network of membranes within eukaryotic cells, involved in protein and lipid synthesis; exists in two forms: rough ER (with ribosomes) and smooth ER (without ribosomes).

Rough Endoplasmic Reticulum (RER)

The region of the endoplasmic reticulum studded with ribosomes, primarily involved in protein synthesis and modification.

Smooth Endoplasmic Reticulum (SER)

The region of the endoplasmic reticulum without ribosomes, primarily involved in lipid synthesis, detoxification, and calcium storage.

Golgi Apparatus

An organelle found in eukaryotic cells that processes and packages proteins and lipids, modifying and sorting them for delivery to other organelles or secretion.

Lysosomes

Membrane-bound cell organelles that contain digestive enzymes; involved in breaking down cellular waste and debris.

Vacuoles

Membrane-bound organelles in plant and fungal cells that store water, ions, nutrients, and waste; also involved in maintaining cell turgor pressure.

Mitochondria

Double-membrane-bound organelles found in eukaryotic cells; the primary site of ATP (adenosine triphosphate) production through cellular respiration.

Chloroplasts

Organelles found in plant cells and eukaryotic algae that conduct photosynthesis, converting light energy into chemical energy.

Peroxisomes

Small, membrane-bound organelles involved in lipid metabolism and detoxification reactions by oxidation.