Nucleus and Cell Cycle

Flashcards covering key concepts related to the nucleus, chromatin, RNA synthesis, and the cell cycle based on lecture notes.

Nucleus

The center of cell activity; contains DNA and is the site of RNA synthesis.

Chromatin

Complex of DNA and proteins that makes up chromosomes in the nucleus.

Nucleolus

Non-membrane structure in the nucleus responsible for rRNA synthesis.

Nuclear envelope

Composed of inner and outer membranes that separate the nucleus from the cytoplasm.

Nuclear pore complex

Octagonal structure that facilitates communication between nucleoplasm and cytoplasm.

Euchromatin

Dispersed, active form of chromatin, involved in RNA synthesis.

Heterochromatin

Condensed, inactive form of chromatin, rich in DNA.

DNA

Deoxyribonucleic acid, the molecule that carries genetic information.

mRNA

Messenger RNA, a type of RNA that conveys genetic information from DNA to the ribosome.

siRNA

Short interfering RNA, inhibits gene expression by degrading mRNA.

DICER

Enzyme that processes double-stranded RNA into siRNA.

Cell cycle phases

Includes G1, S, G2, and M phases, detailing the stages of cell division and replication.

Mitosis

Process of cell division that results in two identical daughter cells.

Prophase

Phase in mitosis where chromosomes condense and the nuclear envelope breaks down.

Metaphase

Phase in mitosis where chromosomes align in the center of the cell.

Anaphase

Phase in mitosis where sister chromatids are separated and pulled to opposite poles.

Telophase

Final phase of mitosis, reformation of the nuclear envelope and the division of cytoplasm.

Ribosomes

Cellular structures that synthesize proteins from amino acids based on mRNA.

Cardiac muscle tissue

Heart muscle tissue characterized by striations and intercalated discs.

Skeletal muscle tissue

Striated muscle tissue under voluntary control of the somatic nervous system.