Topic 1. The Cell: An Introduction to the Basic Units of Life

Cell Theory

A fundamental theory stating that cells are the basic unit of life and that all living organisms are composed of one or more cells.

Matthias Jakob Schleiden and Theodor Schwann

Researchers who proposed that cells are the fundamental unit of life after observing plant and animal tissues.

Rudolf Virchow

Scientist who stated that all cells arise from pre-existing cells, summarizing this concept with the phrase 'omnis cellula e cellula'.

Eukaryotes

Organisms made up of cells that contain a true, membrane-bound nucleus and organelles, such as animals, plants, fungi, and protists.

Prokaryotes

Simpler, unicellular organisms that lack a membrane-bound nucleus and organelles, including bacteria and archaea.

Cytoplasm

The total cellular region encompassing the gel-like cytosol plus all suspended organelles, excluding the nucleus.

Selective Boundary

A property of cells where they are enclosed by a plasma membrane that maintains a distinct internal microenvironment.

Ribosomes

Non-membrane-bound structures that serve as the site of protein synthesis by translating mRNA into polypeptides.

Mitochondria

Organelle known as the energy powerhouses of the cell, responsible for cellular respiration and ATP production.

Lysosomes

Membrane-bound vesicles containing hydrolytic enzymes that degrade cellular waste and foreign materials.

Endoplasmic Reticulum (ER)

An organelle composed of a membranous network involved in protein and lipid synthesis.

Plasma Membrane

The biological membrane that separates and protects the cell's interior from the external environment.

Homeostasis

The process by which cells maintain a stable internal environment despite changes in external conditions.

Tissue Specialization

The process by which cells in multicellular organisms differentiate to perform unique functions efficiently.

Neurons

Excitable cells responsible for transmitting nerve impulses and facilitating communication within the nervous system.

Adipocytes

Fat cells specialized for energy storage, insulation, and cushioning.

Epithelial Tissue

Type of tissue that forms protective barriers and lines internal and external surfaces of the body.

 connectiveTissue

Type of tissue that provides structural support and connection between different parts of the body.

Muscle Tissue

Tissue composed of contractile cells that enable movement and force generation.

Nervous Tissue

Tissue that transmits electrical impulses and coordinates communication in the body.

Gametes

Reproductive cells (spermatozoa and ova) that are involved in sexual reproduction.