Cell Biology and Tissues Lecture Notes

Comprehensive vocabulary flashcards covering plasma membrane structure, cell transport, organelles, the cell cycle, and tissue classifications based on lecture notes.

Phospholipid bilayer

The basic structure of the plasma membrane consisting of hydrophilic heads exposed to water and hydrophobic tails pointing inward.

Hydrophilic

A term meaning "water loving"; describes the heads of phospholipids that are exposed to water on the outside and inside of the cell.

Hydrophobic

A term meaning "water hating"; describes the tails of phospholipids that point inward and are not exposed to water.

Plasma Membrane Thickness

$$7-10\,\text{nm}$$

Glycolipids

Phospholipids with sugar groups attached representing $5\%$ of phospholipids; used for energy and as cell identity markers.

Peripheral proteins

Proteins that are not embedded in the membrane and can be easily removed without disrupting the membrane.

Integral proteins

Proteins that are firmly inserted or embedded in the membrane; removal disrupts the membrane.

Transmembrane proteins

Integral proteins that span all the way through the membrane to help transport particles.

Glycocalyx

Carbohydrate identity markers sticking off glycoproteins and glycolipids in the extracellular matrix, used for cell recognition.

CCR5 receptor antagonists

Experimental HIV drugs designed to interfere with the interaction between CCR5 and HIV, including PRO140, Vicriviroc, Aplaviroc, and Maraviroc.

Tight junction

A type of cell junction that acts as a sealant to prevent substances from leaking between cells.

Gap junction

A type of cell junction used for communication between cells.

Desmosomes

A type of cell junction that functions to resist mechanical stress.

Filtration

The movement of small solutes through a membrane due to pressure.

Tonicity

The ability of a solution to cause a cell to shrink or swell.

Isotonic

A solution with the same solute concentration as the cytosol; causes no change in cell volume.

Hypertonic

A solution with a higher concentration of nonpermeating solutes than the cytosol; causes cells to lose water and shrivel (crenate).

Hypotonic

A solution with a lower concentration of nonpermeating solutes than the cytosol; causes cells to absorb water, swell, and potentially burst (lyse).

Uniport

A carrier protein that moves only one solute at a time.

Symport

A carrier protein that moves two or more solutes simultaneously in the same direction (cotransport).

Antiport

A carrier protein that moves two or more solutes in opposite directions (countertransport), such as the sodium-potassium pump.

Ribosomes

Structures composed of proteins that synthesize proteins; they can be free in the cytoplasm or bound to the rough ER.

Rough Endoplasmic Reticulum

Interconnected membranes that bind ribosomes and function in protein synthesis.

Smooth Endoplasmic Reticulum

Interconnected membranes that synthesize lipids and break down drugs (detoxification).

Golgi apparatus

Flattened membrane sacs called cisternae that modify, pack, and deliver proteins in vesicles.

Lysosomes and Peroxisomes

Spherical membranes containing enzymes that digest waste and detoxify harmful substances.

Mitochondria

Double-membrane organelles known as the "power plants" that produce energy in the form of ATP using oxygen.

Nucleolus

A structure within the nucleus responsible for synthesizing ribosomes.

Chromatin

The state of DNA and proteins (histones) during interphase.

Nucleosome

The functional unit of chromatin consisting of 8 histones with DNA wrapped around them.

Stem cells

Cells that have the ability to develop into one or more types of mature, specialized cells.

Mitosis

The phase of the cell cycle where a cell duplicates its chromosomes and separates them for two daughter cells; consists of prophase, metaphase, anaphase, and telophase.

Apoptosis

The process by which a cell breaks down (programmed cell death).

Tissue

A mass of cells and cell products forming a discrete region of an organ and performing a specific function.

Matrix

The extracellular, non-living material that surrounds cells in a tissue.

Basement membrane

A layer of molecules that anchors an epithelium to the underlying connective tissue and defines the epithelial boundary.

Avascularized

Lacking a direct blood supply; a characteristic of epithelial tissue.

Exocrine glands

Glands that secrete products into ducts; they can be unicellular (goblet cells) or multicellular (saliva, sweat, oil).

Extracellular matrix (ECM)

The combination of fibers (collagen, elastic, reticular) and ground substance located between the cells of connective tissue.