Cell Organelles

Their Structures and Functions

Prokaryotic Bacteria Cell

Eukaryotic Plant Cell

Eukaryotic Animal Cell

Body Cell

Cell (Plasma) Membrane• Structure - The lipid

bilayer that forms the outer boundary of a cell

• Function(s) - Regulates movement of molecules into and out of cells; semipermeable

• Found In - Bacteria, Animal & Plant Cells

Cytosol(Cytoplasm – the cytosol and all the

organelles within the cell)

• Structure - Gelatinous aqueous fluid that fills the cell

• Function(s)

- Suspends the organelles within the cell

- Fills the cell and gives it shape

- Allows nutrients to move about the cell

• Found In - Bacteria, Animal & Plant Cells

Nucleus • Structure - The most prominent organelle, surrounded by a double membrane perforated with pores

• Function(s)

- Regulates all cell activities

- Contains the DNA of the cell

• Found In - Animal and Plant Cells

Nucleolus• Structure - Small

circular structure(s) within nucleus

• Function(s) -Synthesis and partial assembly of ribosomes

• Found In - Animal and Plant Cells

Nucleus & Nucleolus

Nuclear Envelope• Structure - Double

membrane with pores surrounding the nucleus

• Function(s) - Regulates movement of molecules into and out of the nucleus

• Found In - Animal and Plant Cells

Chromatin (DNA) • Structure - Fine strands of genetic information (DNA and protein); coils to form chromosomes

• Function(s)- Contains the code that directs most cell activities- DNA’s code is the instructions for making proteins

• Found In - Bacteria, Animal & Plant Cells

Mitochondria• Structure - A peanut-

shaped organelle which has a double membrane. The inner membrane has many folds.

• Function(s) – Performs cellular respiration; generates ATP (the energy the cell needs to run)

• Found In - Animal and Plant Cells

Mitochondria

Ribosomes• Structure - Dot-like

organelles attached to the rough ER or free in the cytosol

• Function(s) – Reads RNA to synthesize proteins

• Found In - Bacteria, Animal & Plant Cells

Rough Endoplasmic Reticulum

• Structure – a system of membranous tubes and sacs covered with dark dots (ribosomes)

• Function(s)- Makes alterations to proteins produced by ribosomes- Folds proteins into the correct shapes

• Found In - Animal and Plant Cells

Rough ER

Smooth Endoplasmic Reticulum• Structure - A system of

membranous tubules and sacs

• Function(s) - helps move lipids, steroids, and fatty acids within the cell (intracellular highway); regulates calcium levels; breaks down toxic substances

• Found In - Animal and Plant Cells

Golgi Apparatus (Complex)• Structure - A series of

flattened sacs with a characteristic convex shape

• Function(s) – Processes and packages proteins and substances produced by cells; instructs the substances where to go

• Found In - Animal and Plant Cells

Lysosomes

• Structure - Small spherical organelles that enclose digesting enzymes within single membranes

• Function(s) - Digests molecules, old organelles, and foreign substances; recycling center

• Found In - Animal and Plant Cells

Digesting enzymes

Cytoskeleton (microtubules and microfilaments )

• Structure - A network of long protein strands located in the cytosol

• Function(s) - Provides internal shape and support to cells (microfilaments and microtubules)

• Found In - Animal and Plant Cells

Flagella and Cilia

• Structure- Flagella: Whip-like tail(s) extending from the surface of some cells- Cilia: Short hair-like organelles that extend from the surface of some cells

• Function(s)- Propel the cell through the environment- Move materials over the surface of the cell

• Found In- Bacteria and Animal Cells

Flagella (more than 1 flagellum)

Centrioles

• Structure - Cylindrical bodies that appear during cell division

• Function(s) – Help move DNA during division in animal cells

• Found In - Animal cells only

Cell Wall • Structure - A rigid covering that lies outside the cell membrane made of long chains of cellulose

• Function(s) - Provides external protection and support to plant cells

• Found In – Plants cells only(Bacteria can have a cell wall but it is biochemically different from plant cell walls)

Vacuole• Structure - Fluid filled

membranous sac• Function(s) - Stores

enzymes and wastes; cell’s warehouse

• Found In - Animal and Plant Cells

(Can be very large in plants cells, but small in animal cells)

Plastid• Structure - Organelles

surrounded by two membranes and contain their own DNA

• Function(s) - Stores food or pigment

• Found In - Plant cells only

Chloroplast• Structure - Oval organelle

surrounded by a double membrane that encloses a system of flattened membranous sacs

• Function(s) – Contains chlorophyll and performs photosynthesis; a type of plastid.

• Found In - Plant cells only