Cell Biology: Cell Theory, Cell Types, and Organelles

Vocabulary practice flashcards covering cell history, cell theory, prokaryotic vs. eukaryotic differences, viral cycles, cellular domains, and organelle structures and functions.

Robert Hooke

The English scientist who first observed and named 'cells' in 1665 while examining slices of cork under a microscope, comparing their appearance to the small, bare rooms (cells) where monks slept in a monastery.

Anton von Leeuwenhoek

The Dutch microscopist who used simple microscopes in the 1670s to observe and describe living cells.

Compound Light Microscope

An optical instrument that uses more than one lens to magnify specimens hundreds of times.

Electron Microscope

An advanced microscope that utilizes beams of electrons to magnify specimens many thousands of times.

Cell Theory

1) all living things have one or more cells, 2) cells are the basic unit of organization in living things, and 3) cells come from other cells.

Matthias Schleiden

The botanist who contributed to the cell theory in the 1830s by concluding that all plants are made of cells.

Theodor Schwann

The zoologist who contributed to the cell theory in the 1830s by concluding that all animals are made of cells.

Rudolf Virchow

The physician who finalized the classical cell theory in 1855 by establishing that all cells arise from preexisting cells through cell division.

Prokaryote

A simple, single-celled organism—like bacteria or archaea—that has no nucleus or internal compartments. Its DNA floats freely inside the cell as a single loop.

Eukaryote

A single-celled or multicellular organism (plant, animal, fungus, or protist) whose cells contain a distinct nucleus and internal membrane-bound organelles, providing superior organization and energy management.

Universal Cellular Components

The four fundamental cellular structures shared by all cells (both prokaryotes and eukaryotes): cell membrane, cytoplasm, ribosomes, and DNA.

Archaea

Prokaryotes that do not have peptidoglycan (a carbohydrate) in their cell walls.

Bacteria

Prokaryotic whose cell walls contain peptidoglycan.

Eukarya

All Eukaryotes.

Virus

A nonliving particle consisting of genetic material (DNA or RNA) enclosed within a protein coat, incapable of reproducing without hijacking a host cell.

Capsid

The protective protein shell or coat that encloses the viral genome (DNA or RNA).

Lytic Cycle

The active reproductive pathway of a virus in which viral DNA/RNA enters a host cell, takes over cellular metabolism, produces numerous viral copies, and ultimately lysis (explodes) the host cell to release new viruses.

Lysogenic Cycle

A reproductive cycle in which a virus inserts its genetic material and remains dormant inside the host cell for a period of time before initiating the lytic cycle (e.g., HIV).

Cell Membrane

Controls what enters and leaves the cell. Two layers of phospholipids and embedded proteins.

Cytoplasm

Where most of the chemical reactions happen. Metabolism. Salt, Water, organic molecules. Looks like a watery jelly.

Cytoskeleton

Supports the cell. Helps in cell movement. Made of microtubules and microfilaments.

Centrioles

Helps with mitosis. Seen only during mitosis. Found in animal cells. Made of microtubules.

Nucleus

Controls all cellular activities by controlling the production of proteins. Surrounded by the nuclear membrane. Contains DNA and nucleolus.

Nuclear Membrane (Nuclear Envelope)

Controls what enters and leaves the nucleus. Two layers of phospholipids.

Nucleolus

Builds ribosomes. Small, dark spot in the nucleus.

Ribosome

Builds proteins. Made of protein.

Golgi

Packages proteins for transport inside the cell. The package is called a vesicle. A stack of flat sacks, made of membrane.

Rough Endoplasmic Reticulum (RER)

Transports proteins through the cell. System of tunnels, with ribosomes attached. Made of membrane.

Smooth Endoplasmic Reticulum (SER)

Transports other materials. A system of tunnels. Made of membrane.

Vesicle

Package used to transport material inside of the cell. Made by the golgi.

Vacuole

Package made from membrane. Used to store and transport materials. Made by the golgi.

Water Vacuole

Found only in plants. A very large vacuole for storage of water. A big bag of membrane.

Lysosome

A vesicle containing digestive enzymes. Cells use _____ to digest materials inside. A membrane bag of digestive enzymes.

Mitochondria

Where aerobic respiration happens. Contain their own DNA and ribosomes.

Chloroplast

Where photosynthesis happens. Two layers of membrane. Has chlorophyll pigment contained in thylakoids.

Cell Wall

Gives the cell support and helps to protect the cell. Examples in plants, fungi, archaea, and bacteria.

Cilia

Movement. Used like an oar. Thin, hairlike. Made of microtubules.

Flagella

Movement. Used like a propeller. Thicker, longer. Made of microtubules.