BIOL1406 Lecture Unit 2 Review

Cell Signaling

The process by which cells communicate with each other, crucial for various biological functions and covered in Chapter 7.

Endomembrane System

A system within the cell that includes the Golgi apparatus and is involved in the trafficking and processing of proteins and vesicles.

Vesicle

A small membrane-bound sac that transports materials within the cell.

Electron Microscopy

A microscopy technique that allows for the visualization of smaller cellular structures compared to light microscopy.

Endosymbiosis Theory

The theory that eukaryotic cells originated from prokaryotic cells engulfing other prokaryotic cells, leading to a symbiotic relationship.

Rough Endoplasmic Reticulum (RER)

A type of endoplasmic reticulum with ribosomes on its surface, involved in protein synthesis.

Smooth Endoplasmic Reticulum (SER)

A type of endoplasmic reticulum without ribosomes, involved in lipid synthesis and detoxification.

Cytoskeleton

A network of fibers that helps maintain cell shape and structure.

Central Vacuole

A large liquid storage vesicle found in plant cells, important for maintaining turgor pressure.

Chloroplasts

Organelles in plant cells responsible for photosynthesis.

Mitochondria

Organelles responsible for ATP production, often found in higher numbers in energy-demanding cells like muscle cells.

Fluid Mosaic Model

A model describing the structure of cell membranes, highlighting the fluid nature of the lipid bilayer and the presence of various proteins.

Integral Membrane Proteins

Proteins that are embedded within the lipid bilayer of cell membranes.

Peripheral Membrane Proteins

Proteins that are attached to the exterior or interior surfaces of cell membranes but are not embedded.

Exocytosis

The process by which cells secrete materials to the outside by vesicle fusion with the plasma membrane.

Endocytosis

The process by which cells engulf external substances, bringing them into the cell via vesicles.

Ligand

A molecule that binds to a receptor to initiate a cellular response.

Receptor

A protein that binds to a specific ligand, triggering a cellular response.

Signal Transduction

The process by which a cell converts an external signal into a functional response.

Transcription Factor

A protein that regulates gene expression by binding to DNA.

G Protein-Coupled Receptors (GPCRs)

A large family of receptors that activate G proteins upon ligand binding, initiating a signaling cascade.

Receptor Tyrosine Kinases (RTKs)

A class of receptors that, upon ligand binding, phosphorylate tyrosine residues on themselves and other proteins, leading to cellular responses.

Secondary Messenger

A small molecule that relays signals received at receptors on the cell surface to target molecules inside the cell.

Phosphorylation

The addition of a phosphate group to a protein, often resulting in a conformational change that activates or deactivates the protein.

Agonist

A molecule that binds to a receptor and activates it, mimicking the action of a natural ligand.

Antagonist

A molecule that binds to a receptor but does not activate it, blocking the action of the natural ligand.

Affinity

The strength of the interaction between a ligand and its receptor, often measured by the dissociation constant (Kd).

Kd (Dissociation Constant)

A measure of the affinity between a ligand and its receptor; lower Kd indicates higher affinity.

Paracrine Signaling

A form of cell signaling where a cell secretes a signal that affects nearby cells.