Introduction to Cells and Cell Organelles

A comprehensive vocabulary study set covering cell theory history, differences between prokaryotic and eukaryotic cells, and the specific functions and distributions of cell organelles.

Robert Hooke

First scientist to describe cells in cork.

Anton van Leeuwenhoek

Improved the microscope and observed bacteria and protozoa.

Theodore Schwann and Mattias Schleiden

Developed the original cell theory.

Rudolph Virchow

Provided the last tenet of cell theory: cells come from existing cells.

All living things are made of one or more cells, cells are the basic unit of life, and all cells come from existing cells.

3 Tenets of Cell Theory

Prokaryotic Cell

Small in size, always unicellular, has no nucleus, contains circular DNA, and has no membrane bound organelles.

Eukaryotic Cell

Larger in size, unicellular or multicellular, has a nucleus, has membrane bound organelles, and contains linear DNA.

Membrane Bound Organelle

An organelle that is surrounded by its own membrane.

Cell membrane, cytoplasm, ribosomes, DNA, flagella, and cytoskeleton.

organelles shared by all cells

Nucleoid, capsule, plasmid, and pili

organelles only in prokaryotes

Chloroplast, central vacuole, and plasmodesmata.

organelles only in plant cells (3)

Cilia, lysosome, centrosome, and intermediate filaments.

organelles only in animal cells (4)

Nucleus, nucleolus, rough and smooth ER, golgi body, vesicles, mitochondria, vacuole, peroxisome, microtubules, and microfilaments.

organelles only in eukaryote cells (11)

Cell Wall

Provides shape, structure, and protection for the cell; found only in prokaryotes and plant cells.

Cell Membrane

Maintains homeostasis by controlling what enters and leaves the cell.

Ribosomes

Makes proteins by helping connect amino acids together.

Cytoplasm

Suspends organelles and provides an environment for chemical reactions within the cell.

Nucleus

Stores genetic information (DNA).

Nucleolus

Makes ribosomes.

Rough ER

Makes and transports proteins.

Smooth ER

Makes lipids and membranes, detoxifies liver, and stores calcium.

Golgi Body

Modifies, sorts, and ships proteins using vesicles.

Vesicles

Specialized membrane bound structures used to modify, sort, and ship proteins.

Mitochondria

Creates energy (ATP) from sugar (glucose); is the site of cellular respiration.

Lysosome

Uses enzymes to break down large molecules, bacteria, viruses, and old organelles, recycling old cell parts.

Centrosome

Creates special structures called spindle fibers that are used in cell division.

Chloroplast

The site of photosynthesis, which uses the sun's energy to produce sugar.

Central Vacuole

Stores water in order to maintain plant shape; if a plant needs water, it wilts.

Vacuole

Stores food or wastes within the cell, and stores water in animal cells.

Cytoskeleton

Network of proteins found throughout the cell that provides structure for cells and movement of organelles.

Microtubule

A hollow tube cytoskeletal protein found in eukaryotic cells that provides structural support.

Microfilament

Thin solid rod that helps maintain shape and contractile movements, forms contractile ring of cleavage furrow, and guides cell division.

Intermediate Filament

Provides permanent structural support to anchor organelles in place.

Peroxisome

Found in eukaryotic cells; uses enzymes to detoxify compounds.

Plasmodesmata

Found in plant cells; helps with transport of materials to and from adjacent cells through the cell wall.

Flagella

Long appendages on the outside of cells that help with movement using propeller motions.

Cilia

Short hair-like appendages on the outside of cells that help with movement using back and forth motions.

Nucleoid

Found in the central region of the cell, where DNA is stored and acts as a control center for a prokaryote cell.

Capsule

Structure outside the cell wall that helps with sticking to surfaces and provides a further layer of protection.

Plasmid

Separate pieces of DNA that are usually ring-shaped and smaller than the main chromosome of a cell, often involved in gene transfer and antibiotic resistance.

Pili

Hair-like structures on the surface of some prokaryotes that aid with attachment to other bacteria or surfaces to stabilize (keep still) during DNA transfer or infecting hosts.