CYTOLOGY

Catabolism

The process of breaking down complex molecules into simpler ones, releasing energy.

Cell Membrane

The semi-permeable barrier surrounding a cell, controlling what enters and exits; also called the plasma membrane.

Cilia

Hair-like structures on the cell surface that aid in movement or cleaning of surfaces, such as the trachea.

Contractility

The ability of a cell to shorten or generate force in response to stimuli.

Cytoplasm

The substance within a cell that contains organelles and other components, excluding the nucleus.

Endocytosis

The process by which cells ingest material from their environment, including pinocytosis (cell drinking) and phagocytosis (cell eating).

Enzymes

Biological catalysts that speed up chemical reactions within cells, required for life.

Euchromatin

The less condensed form of chromatin, rich in genes and readily transcribed for protein synthesis.

Exocytosis

The process by which cells release substances into their external environment.

Free Water

Water in the cell that is available for chemical reactions; acts as a solvent.

Glycocalyx

The loose carbohydrate coat on the outside of the cell membrane, composed of glycolipids, glycoproteins, and proteoglycans.

Glycogen

A polymer of glucose, serving as a storage form of carbohydrate for energy use.

Golgi Complex

An organelle that processes and packages proteins and lipids, preparing them for transport or secretion.

Heterochromatin

The highly condensed, transcriptionally inactive form of chromatin, typically staining darker in microscopy.

Homeostasis

The ability of a cell to maintain a stable internal environment.

Hydrolytic Enzymes

Digestive enzymes that use water to break down molecules; they are present in lysosomes.

Irritability

The ability of a cell to respond to environmental stimuli.

Karyolymph

The soluble phase of nuclear material, also known as nuclear ground substance or nuclear sap.

Lipids

Fat-soluble molecules important for cell membrane structure and energy storage; insoluble in water.

Lysosomes

Organelles containing hydrolytic enzymes used for intracellular digestion.

Metabolism

All the chemical reactions in a cell, including anabolism and catabolism.

Mitochondria

The powerhouses of the cell, responsible for producing ATP by oxidizing nutrients.

Nuclear Membrane

The double membrane separating the nucleus from the cytoplasm.

Nucleolus

A structure within the nucleus involved in ribosome assembly.

Nucleus

The central control center of the cell that houses the DNA.

Peroxisome

A vesicle that contains oxidative enzymes, used to detoxify substances.

Plasma Membrane

The outer boundary of the cell, responsible for selective transport.

Protoplasm

The collective term for all substances that make up the cell, including water, electrolytes, proteins, lipids, and carbohydrates.

Ribosomes

Organelles that synthesize proteins, either free in the cytoplasm or attached to the endoplasmic reticulum.

Rough Endoplasmic Reticulum (RER)

A network of membranes with attached ribosomes, involved in protein synthesis.

Smooth Endoplasmic Reticulum (SER)

A network of membranes without ribosomes, involved in lipid metabolism and detoxification.

Structure-Function Relationship

The principle that the structure of a cell or its components dictates its function.

Active Transport

Movement of molecules across a cell membrane against their concentration gradient, requiring energy.

ATP (Adenosine Triphosphate)

The primary energy currency of the cell, used to power cellular processes.

Cell Cycle

A series of events that cells go through, including growth, DNA replication, and division.

Centrioles

Paired cylindrical structures that organize microtubules during cell division.

Chromatin

The complex of DNA and proteins that makes up chromosomes.

Cristae

The folds of the inner membrane of the mitochondria, increasing surface area for energy production.

Cytoskeleton

A network of protein filaments in the cell that provides structural support and facilitates cell movement and division.

Differentiation

The process by which cells become specialized in structure and function.

Endoplasmic Reticulum (ER)

A network of membranes in the cell, involved in protein and lipid synthesis.

Flagella

Long, whip-like cellular extensions that facilitate cell movement.

Inclusions

Non-membrane-bound structures in the cytoplasm, such as pigment and lipid droplets, and glycogen granules.

Membrane Transport

The movement of molecules across the cell membrane, including passive and active mechanisms.

Microfilaments (Actin Filaments)

Thin protein filaments that assist with cell movement and shape changes.

Microtubules

Hollow protein tubules that provide structural support and facilitate intracellular transport.

Oxidative Phosphorylation

The process by which ATP is generated in the mitochondria.

Passive Transport

Movement of molecules across a cell membrane along their concentration gradient without energy.

Secretory Granules

Membrane-bound vesicles containing products to be secreted from the cell.