CELS191 Lecture 3: Plasma Membrane & Organelles

A collection of 80 vocabulary flashcards based on the CELS191 Lecture 3 content covering the plasma membrane and organelles.

Plasma Membrane

A semi-permeable barrier that surrounds each cell, composed of a phospholipid bilayer.

Phospholipid Bilayer

Structure made up of two layers of phospholipids that forms the plasma membrane.

Membrane Proteins

Proteins embedded in or associated with the phospholipid bilayer, vital for various cellular functions.

Passive Transport

The movement of molecules across a cell membrane without the need for energy.

Active Transport

The movement of molecules against their concentration gradient, requiring energy (ATP).

Co-Transport

Indirect active transport where the movement of one substance across a membrane powers the movement of another substance.

Signal Transduction

The process by which cells respond to external signals through membrane proteins.

Cell Recognition

The ability of cells to identify and communicate with each other, often via glycoproteins.

Osmosis

The diffusion of water across a semi-permeable membrane from an area of low solute concentration to high.

Diffusion

The movement of molecules from an area of high concentration to an area of low concentration without energy.

Facilitated Diffusion

Movement of hydrophilic molecules across the cell membrane via specific channels and carriers.

Aquaporins

Channels in the membrane that facilitate the rapid transport of water.

Endoplasmic Reticulum (ER)

An organelle involved in protein and lipid synthesis.

Lysosome

Organelle that contains enzymes for digestion and waste removal.

Mitochondrion

Powerhouse of the cell where ATP (energy) is produced, has two membranes.

Nucleus

The organelle that houses the cell's DNA and coordinates activities such as growth and reproduction.

Fluid Mosaic Model

Describes the plasma membrane as a dynamic and fluid structure with various proteins embedded.

Cholesterol

A lipid that stabilizes the fluidity of the membrane.

Semi-Permeable

Characteristic of membranes allowing certain molecules to pass while restricting others.

Hydrophilic

Molecules that are attracted to water; typically polar and can form hydrogen bonds.

Hydrophobic

Molecules that repel water; typically non-polar and do not mix with water.

Concentration Gradient

The difference in the concentration of a substance between two areas.

Cytoskeleton

Network of protein fibers that provide structural support to the cell.

Extracellular Matrix (ECM)

Complex network of proteins and sugars outside of the cell that supports and regulates cell activities.

Glycoproteins

Proteins that have carbohydrate chains attached, important for cell recognition.

Integral Proteins

Proteins that span the membrane and are involved in transport and signaling.

Peripheral Proteins

Proteins located on the surface of the membrane, involved in signaling and maintaining the cell's shape.

Cellular Compartmentalization

Separation of different activities and conditions within different organelles in a cell.

Transport Proteins

Proteins that assist in moving substances across the plasma membrane.

Sodium-Potassium Pump

An example of an active transport mechanism that maintains the electrochemical gradient across the cell membrane.

Cellular Materials

Biomolecules that are produced and used by the cell for various functions.

Waste Removal

The process by which cells eliminate unneeded or harmful substances.

Cell Energy Generation

Processes that produce energy for cellular activities, such as cellular respiration.

Phospholipid

A molecule that forms the bilayer of cell membranes, having a hydrophilic head and hydrophobic tails.

Dynamic Equilibrium

State reached when diffusion and osmosis continue to occur but there is no net movement of molecules.

Hypertonic Solution

A solution with a higher solute concentration compared to another.

Hypotonic Solution

A solution with a lower solute concentration compared to another.

Isotonic Solution

A solution with equal solute concentration compared to another.

Membrane Fluidity

The viscosity of the lipid bilayer of a cell membrane, which affects the movement and function of proteins.

Concentration Gradient

The difference in concentration of a substance across a distance.

Exocytosis

The process by which a cell expels materials in vesicles.

Endocytosis

The process by which cells internalize substances from their environment.

Vesicle

A small membrane-bound sac that transports substances within a cell.

Cell Compartment

Distinct regions within a cell where specific functions occur.

Biological Membranes

Membranes that separate and protect the cell and its internal structures.

Cytoplasm

The cellular fluid surrounding organelles within the cell.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product.

Cell Signaling

The process through which cells communicate with one another.

Endomembrane System

A network of membranes within the cell that includes the nuclear envelope, ER, and Golgi apparatus.

Membrane Dynamics

Changes in membrane structure and composition that occur in response to cellular activity.

Concentration Regulation

Processes by which cells maintain optimal concentrations of various substances.

Homeostasis

The ability of cells to maintain stable internal conditions despite external changes.

Cellular Metabolism

The sum of all biochemical reactions occurring within a cell.

Molecular Channels

Specific protein structures in membranes that facilitate the transport of ions and molecules.

Transport Mechanism

The method by which substances are moved across membranes.

Biochemical Gradients

Differences in concentration of biochemical substances across membranes.

Vacuole

A membrane-bound organelle in plant cells that stores substances and helps maintain turgor pressure.

Plant Cell Structures

Unique components such as cell walls, chloroplasts, and large central vacuoles.

Animal Cell Structures

Characteristics including multiple lysosomes and smaller vacuoles compared to plant cells.

Homeostatic Mechanisms

Systems that maintain stability in cell functions and internal conditions.

Scientific Inquiry

The process of asking questions and seeking answers through experimentation and observation.

Cellular Communication

The various ways in which cells interact and signal to each other.