Anatomy & Physiology I – Cell Biology

Vocabulary flashcards based on key concepts from the lecture on Cell Biology, covering membrane structures, transport mechanisms, cell organelles, and metabolic processes.

Plasma Membrane

The membrane that separates the internal part of the cell from the external environment and controls the movement of materials in and out.

Phospholipid Bilayer

A double-layer of phospholipids forming the basic structure of the plasma membrane.

Amphipathic

A molecule that has both hydrophilic and hydrophobic parts.

Peripheral Proteins

Proteins that attach loosely to the inner or outer surface of the membrane.

Integral Proteins

Proteins that extend deeply into the membrane, often spanning from one surface to the other.

Transmembrane Protein

Integral proteins that span across the membrane appearing on both surfaces.

Marker Molecules

Cells use these molecules to identify other cells or molecules.

Glycoproteins

Proteins that have carbohydrates attached, involved in marker molecule function.

Glycolipids

Lipids that have carbohydrates attached.

Transport Proteins

Proteins that transport ions and molecules across the membrane.

Specificity

The ability of a transport protein to bind to only certain types of ions or molecules.

Competition

Occurs when molecules with similar shapes compete to bind to a transport protein.

Saturation

The rate of movement across the membrane is limited by the number of available transport proteins.

Channel Proteins

Integral proteins that form channels through the plasma membrane.

Gated Ion Channels

Channel proteins that open and close based on certain conditions.

Leakage Channels

Mostly open channels responsible for plasma membrane permeability at rest.

Ligand-gated Ion Channels

Channels that open or close in response to chemical signals.

Voltage-gated Ion Channels

Channels that respond to changes in membrane potential.

Carrier Proteins

Proteins that bind to molecules and undergo a conformational change to transport them.

Uniport

A carrier protein that moves one type of molecule in one direction.

Antiport

A carrier protein that moves two different molecules in opposite directions.

Symport

A carrier protein that moves several molecules in one direction.

ATP-Driven Transport

Movement of molecules using energy derived from ATP.

Receptor Proteins

Proteins with a receptor site that bind specific signals and initiate cellular responses.

Permeability

The property of a membrane that allows substances to move across it.

Selective Permeability

The ability of a cell membrane to allow certain substances to pass while restricting others.

Diffusion

The net movement of substances from an area of high concentration to an area of low concentration.

Simple Passive Diffusion

Diffusion across a membrane without energy usage.

Facilitated Diffusion

The process of moving molecules across a membrane via transport proteins, without using ATP.

Active Transport

The energy-dependent process of moving molecules against their concentration gradient.

Primary Active Transport

Transport that directly uses ATP to move molecules against their gradient.

Sodium-Potassium Pump

A primary active transport mechanism that transports Na+ out and K+ into the cell.

Secondary Active Transport

Transport that indirectly uses energy from ion gradients established by primary active transport.

Osmosis

The diffusion of water molecules across a selectively permeable membrane.

Hypertonic

A solution with a high concentration of solutes.

Hypotonic

A solution with a low concentration of solutes.

Isotonic

A solution with equal concentrations of solute and solvent.

Exocytosis

The process by which vesicles fuse with the membrane to release their contents outside the cell.

Endocytosis

The process of taking substances into the cell by engulfing them with the plasma membrane.

Phagocytosis

The engulfing of undissolved materials by a cell, also known as cellular eating.

Pinocytosis

The process by which a cell engulfs liquid substances, also known as cellular drinking.

Receptor-mediated Endocytosis

The uptake of specific substances via their binding to receptors on the cell surface.

Transcytosis

The process where substances are transported through a cell via vesicles.

Cytoplasm

The portion of the cell’s content outside the nucleus but within the plasma membrane.

Nuclear Envelope

A membrane structure that encloses the nucleus.

Chromatin

Threadlike matrix within the nucleus that contains DNA.

Nucleolus

A prominent structure in the nucleus involved in ribosome synthesis.

Ribosome

Site of protein synthesis, made of RNA and protein.

Free Ribosomes

Ribosomes that exist in the cytosol and produce proteins for intracellular use.

Bound Ribosomes

Ribosomes attached to the endoplasmic reticulum, producing proteins for export.

Endoplasmic Reticulum (ER)

A network of membrane-bound spaces involved in synthesis and transportation of proteins and lipids.

Rough Endoplasmic Reticulum (RER)

ER with ribosomes attached, synthesizing proteins destined for export.

Smooth Endoplasmic Reticulum (SER)

ER without ribosomes, involved in lipid and hormone synthesis.

Golgi Apparatus

An organelle that modifies and packages proteins and lipids into vesicles.

Lysosome

A membrane-bound sac containing enzymes for digestion of cellular debris.

Vacuole

Membrane-bound sacs containing water and dissolved materials.

Peroxisome

Metabolic organelles involved in the breakdown of fatty acids and detoxification.

Catalase

An enzyme that converts hydrogen peroxide into water.

Mitochondria

Organelles known as the powerhouse of the cell, generating ATP.

Cristae

Infoldings of the inner mitochondrial membrane where the electron transport chain is located.

Matrix

The space within the inner mitochondrial membrane containing enzymes for the Krebs cycle.

Cytoskeleton

A network of proteins providing structural support and movement for the cell.

Microtubules

Cytoskeletal components that provide support and motility, made of tubulin.

Intermediate Filaments

Cytoskeletal components that help maintain cell shape and mechanical strength.

Microfilaments

Cytoskeletal components made of actin and myosin, involved in cell motility.

Flagella

Long, whip-like structures that aid in cell movement.

Cilia

Short, hair-like structures that help move materials across cell surfaces.

Centrioles

Cylindrical structures involved in cell division and forming spindle fibers.

Desmosomes

Protein attachments that anchor adjacent cells together.

Hemidesmosomes

Structures that anchor cells to the basement membrane.

Tight Junctions

Seams between cells that prevent the passage of materials between them.

Gap Junctions

Narrow tunnels between cells that allow for communication and material exchange.

Adherens Junction

Cell junctions that help resist separation and maintain cellular integrity.

Cell Junctions

Structures that connect cells, aiding in communication and stability.

Aquaporins

Channel proteins that facilitate the transport of water across the cell membrane.

Krebs Cycle

A series of reactions in mitochondria that produces energy through the oxidation of acetyl-CoA.

Hydrolysis

The process of breaking down molecules by the addition of water.

Concentration Gradient

The difference in concentration of a substance across a space.

Kinetic Energy

Energy of motion that affects molecular movement and diffusion rates.

Viscosity

The resistance of a fluid to flow, affecting diffusion rates.

Counter Transporter

A transport protein that moves substances in opposite directions.

Cotransporter

A transport protein that moves multiple substances in the same direction.

Ion Channels

Proteins that allow specific ions to move across membranes.

Cellular Respiration

The process by which cells convert biochemical energy from nutrients into ATP.

Electrochemical Gradient

A gradient that affects the movement of ions across membranes.

Signal Transduction

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

Ligand

A molecule that binds specifically to another molecule, often a receptor.

Endosome

An intracellular compartment formed during endocytosis.

Clathrin-Covered Pits

Regions of the plasma membrane that are coated with clathrin and involved in receptor-mediated endocytosis.

Secretory Vesicles

Small sacs that transport and release substances from within a cell.

Nucleus

The membrane-bound organelle that contains the cell's genetic material.

Cell Membrane

The outer boundary of a cell that controls the passage of materials.

Cell Theory

The theory that all living things are made of cells, and that cells are the basic unit of life.

Endocytosis Types

Includes phagocytosis, pinocytosis, and receptor-mediated endocytosis.

Cell Function

The specific activities carried out by a cell, including metabolism and energy production.

Oocyte Recognition

The process by which sperm cells identify and bind to an egg cell during fertilization.

Transmembrane Domain

The region of integral proteins that spans across the lipid bilayer.

Cellular Integrity

The maintenance of the physical and functional state of a cell.

Organelles

Specialized structures within cells that perform distinct functions.

Cell Growth

The process of cellular expansion and increase in size.