Prokaryotic and Eukaryotic Cell Structures

Circular chromosome

Part of the prokaryotic cell where the DNA is found.

Plasmid

Small, separate piece of DNA.

Cell membrane

Innermost covering of the cell made up of phospholipids.

Cell wall

Made up of a special mix of polysaccharides and proteins; antibiotics break it down.

Capsule

Outside of the cell wall, protective covering; not all bacteria have it.

Flagella (sing. Flagellum)

Moves bacteria.

Cytoplasm

Dissolves substances, place for life processes.

Ribosomes

Organelles that make proteins in the cytoplasm.

Fimbriae

These extensions allow bacteria to stick to various surfaces.

Sex pilus

Helps bacteria to exchange DNA with each other.

Eukaryotic Cells

Includes Protists, Fungi, Plants, and Animals; have nucleus and organelles surrounded by phospholipid membranes.

Organelles

Structures found inside of the cytoplasm specialized to perform certain functions by creating compartments with unique compositions.

Eukaryotic cells size

Much larger and more complex than prokaryotic cells (10-100 µm).

Nucleus

Contains most of the cell's DNA and proteins in the form of linear chromosomes; responsible for regulating cell functions and storing genetic information.

Nuclear envelope

Protects the DNA in the nucleus; nuclear pores allow the exchange of materials.

Rough ER

Comprised of a network of tubes and flattened sacs; site of protein synthesis (consists of ribosomes) and protein folding.

Smooth ER

Folded membrane with no ribosomes on its surface; site of lipid and carbohydrate synthesis and hydrolysis, performs detoxification and stores calcium ions.

Golgi Apparatus

Connected with ER; modification, storage, and packaging of proteins and other molecules; 'tags' proteins for correct destination.

Lysosomes

Contain hydrolytic enzymes; digestion of nutrients, bacteria, and damaged organelles.

Vacuoles

Small membrane structure in animals, really large in older plant cells; storage of chemicals, cell enlargement and support.

Vesicles

Small membrane bubbles without enzymes; ship materials within and out of the cell.

Chloroplasts

Only found in eukaryotic autotrophs; conversion of light energy to chemical energy of sugars (site of photosynthesis).

Mitochondria

Found in every eukaryotic cell; conversion of chemical energy of organic matter to chemical energy (parts of cellular respiration).

Cytoskeleton

Protein structures of the cell; maintenance of cell shape, anchorage for organelles, movement of organelles within cells.

Centrioles

Important for cell division in animals.

Cilia and flagella

Move the cell or move substances on the cell; not organelles but cell structures.