Cell Biology and Cytology Lecture

A comprehensive set of vocabulary flashcards covering cell structure, functions, organelles, and microscopy based on the lecture notes.

Cytology

The study of cells, which are only visible by microscopy and are measured in micrometers ($\mu m$).

Light microscopy (LM)

A type of microscopy where visible light passes through the cell to create an image.

Transmission electron microscopy (TEM)

A type of microscopy where a beam of electrons passes through a thin slice of a specimen to provide a 2D image.

Scanning electron microscopy (SEM)

A type of microscopy where a beam of electrons bounces off the surface of a cell to provide a 3D image of the cell surface.

Plasma membrane

An extremely thin outer border on a cell that serves as a selective barrier regulating the passage of gases, nutrients, and wastes.

Phospholipids

The most common lipid in plasma membranes, consisting of a polar (charged) region and a nonpolar (uncharged) region that spontaneously form a bilayer.

Cholesterol

A lipid that makes up about $20\%$ of membrane lipids and functions to strengthen and stabilize the membrane against extreme temperature.

Glycolipids

Lipids making up $5$ to $10\%$ of membrane lipids that have carbohydrate molecules attached, forming the glycocalyx.

Integral Proteins

Proteins embedded in the phospholipid bilayer that span the entire thickness of the membrane; also called transmembrane proteins.

Peripheral Proteins

Proteins that are not embedded in the lipid bilayer but are loosely attached to the external or internal surface of the plasma membrane.

Glycocalyx

The external surface of the plasma membrane formed by glycoproteins and glycolipids.

Cytosol

A viscous, syruplike fluid in the cytoplasm containing dissolved substances such as ions, nutrients, proteins, carbohydrates, and lipids.

Inclusions

Large storage aggregates of complex molecules found in the cytosol, such as melanin or glycogen.

Organelles

Meaning "little organs," these are specialized structures within a cell that perform specific functions through a division of labor.

Smooth Endoplasmic Reticulum (SER)

A membrane-bound organelle responsible for lipid synthesis, carbohydrate metabolism, and detoxification of drugs, alcohol, and poisons.

Rough Endoplasmic Reticulum (RER)

A membrane-bound organelle with attached ribosomes that functions to synthesize, transport, or store proteins for secretion, the plasma membrane, or lysosomes.

Cisternae

The enclosed spaces or membrane-bound tunnels within the endoplasmic reticulum.

Golgi Apparatus

A series of stacked cisternae that receive proteins and lipids from the RER for modification, sorting, and packaging.

Cis-face

The receiving region of the Golgi apparatus.

Trans-face

The shipping region of the Golgi apparatus.

Lysosomes

Vesicles generated by the Golgi apparatus containing enzymes used to digest waste products and damaged organelles.

Autophagy

The process by which lysosomes digest and remove waste products and damaged organelles within the cell.

Autolysis

The process where a dying cell releases lysosomal enzymes to digest itself.

Peroxisomes

Vesicles formed by the rough ER that use oxygen and the enzyme catalase to detoxify harmful molecules and break down fatty acids.

Mitochondria

Bean-shaped, double-membrane organelles that produce ATP by cellular respiration; often called the "powerhouses" of the cell.

Cristae

The shelf-like folds of the inner membrane of the mitochondria where ATP is produced.

Matrix

The internal fluid contained within the mitochondria.

Ribosomes

Non-membrane-bound organelles comprised of large and small subunits responsible for protein synthesis.

Cytoskeleton

A network of proteins organized as solid filaments or hollow tubes (microfilaments, intermediate filaments, and microtubules) that provide structural support and facilitate movement.

Centrosome

A nonmembranous spherical structure adjacent to the nucleus that contains a pair of centrioles.

Centrioles

Structures composed of nine sets of microtubule triplets involved in organizing microtubules and causing chromosomal migration during cell division.

Cilia

Cytoplasmic projections grouped on cells that move objects across the cell surface.

Flagella

Long, usually singular projections used to propel a cell (e.g., sperm).

Microvilli

Thin, microscopic projections of the plasma membrane that are not capable of motion and function to increase surface area for membrane transport.

Nucleus

The control center for cellular activity that houses genetic material.

Nuclear envelope

A double membrane structure that controls the entry and exit of molecules from the nucleus and is continuous with the endoplasmic reticulum.

Nuclear pores

Selectively permeable channels in the nuclear envelope that allow specific molecules in and out of the nucleus.

Nucleoli

Dark-staining bodies within the nucleus responsible for making the components of ribosome subunits.

Chromatin

The unwound, fine filaments of DNA present when the cell is not dividing.

Chromosomes

Tightly coiled structures formed from chromatin during cell division.