Cell Signaling

Cell signaling

A process for communication and coordination of activities within an organism.

Direct/adjacent signaling

Occurs when the cells producing and receiving signals are in physical contact.

Cell-cell recognition

When signals are received by a cell through receptor proteins on its surface.

Cell junctions

Openings between cells that allow signals to travel through, like plasmodesmata or gap junctions.

Local signaling

Close proximity signaling that does not involve direct contact.

Paracrine signaling

Signaling that releases signals to nearby cells, such as growth factors.

Synaptic signaling

Signaling that occurs exclusively between nerve cells involving neurotransmitters.

Long-distance signaling

Signaling that usually travels through blood, often involving hormones.

Endocrine signaling

Signaling involving the release of hormones to communicate with distant cells.

Reception

The process by which a specific receptor protein receives a signal.

Transduction

Processes that occur after reception, involving relay molecules in the signal transduction pathway.

Response

The final outcome of the signal, fulfilling the necessary function for the cell.

Cell cycle

The life cycle of the cell, including cell division to produce genetically identical cells.

Interphase

The longest phase of the cell cycle, where the cell grows and prepares for division.

G1 phase

The phase where the cell grows and begins doubling specific organelles.

S phase

The phase of the cell cycle where DNA is replicated and the cell continues to grow.

Chromatin

The complex of DNA and proteins that forms chromosomes.

Chromosomes

Structures that contain DNA and are visible during cell division.

Genome

The complete set of chromosomes in a cell.

Somatic cells

Body cells that are diploid, with two sets of genetic information.

Gametes

Haploid sex cells (egg and sperm) that contain one set of genetic information.

Centromere

The region where sister chromatids are tightly connected.

G2 phase

The phase where the cell completes growth and duplicates the centrosome.

Mitosis

The first phase of the mitotic phase where the nucleus divides.

Prophase

The first step of mitosis where chromosomes condense and the nuclear envelope disappears.

Prometaphase

The second phase of mitosis where the nuclear envelope breaks down and spindle fibers attach to kinetochores.

Metaphase

The third phase of mitosis where chromosomes align along the metaphase plate.

Anaphase

The fourth phase of mitosis where sister chromatids become full chromosomes.

Telophase

The final phase of mitosis where chromosomes decondense and nucleoli reappear.

Cytokinesis

The division of the cytoplasm resulting in two daughter cells.

Cleavage

The method animal cells undergo cytokinesis using an actin and myosin ring.

Cell plate

The structure formed by plant cells during cytokinesis to create a new cell wall.

Cell cycle control system

Regulates the cell cycle using checkpoints that assess whether to move to the next phase.

Checkpoints

Regulatory points in the cell cycle that determine if the cell can progress.

G0 phase

A phase where cells enter when they do not receive signals to move forward in the cell cycle.

Cyclin

An internal signal that activates CDKs to help pass the G2 checkpoint.

Growth factors

Local signals that stimulate cell division, such as PDGF.

Density-dependent inhibition

A direct signal that stops cell division when spatial constraints arise.

Anchorage dependence

A direct signal that promotes division only if a proper attachment is available.

Transformation

The process when cells lose control of the cell cycle and divide unchecked.

Benign tumors

Non-cancerous tumors that do not spread and can typically be removed.

Malignant tumors

Cancerous tumors that invade organs and can metastasize through circulation.

Metastasis

The spread of cancer cells through blood or lymph vessels.

Treatment of malignant tumors

Includes chemotherapy, radiation, or surgery.