Cell Organelles

Prokaryotic Cells vs. Eukaryotic Cells

Prokaryote• Smaller• May contain internal

membranes but are far less complicated.

• Carry out all activity associated with living things.

• Genetic material is not contained in a nucleus!!!

Eukaryote• Tend to be larger.• Contain complex

organelles and internal membranes.

• Carry out all activity associated with living things.

• Genetic material is contained within the nucleus!!!

Prokaryotic Cells: Bacteria

Eukaryotic Cells: Animals, Plants, Fungi, and Protists

Cell Organelles

• Organelle: literally, “little organs”. These are the parts of the cell that have specialized functions.

• Cell divided into two divisions: – Cytoplasm: everything inside the cell but outside of

the nucleus.

– Nucleus: inside the cell and inside the nuclear envelope.

Nucleus

• Control center of the cell (main office).• Surrounded by a nuclear envelope- bi-layer

membrane with thousands of nuclear pores that allow chemicals into and out of the nucleus.

• The nucleus contains all of the cell’s DNA in the form of chromatin (DNA bound to protein).

• When the cell begins to divide the chromatin condenses into chromosomes.

• Inside the nucleus there is a small dense portion known as the nucleolus. This is where ribosomes are created.

Nucleus

Ribosomes

• Where proteins are assembled (the classrooms of the cell).• These are really little particles of RNA and protein. They

can be found on the endoplasmic reticulum or floating free in the cytoplasm.

Rough Endoplasmic Reticulum (RER)

• An internal membrane system that contains ribosomes on its surface. (hallways with classrooms)

Smooth Endoplasmic Reticulum (SER)

• An internal membrane where lipids are synthesized. Lacks ribsomes! (hallways with no classrooms but other important rooms)

Golgi Apparatus

• Proteins are produced on ribosomes in the RER and then they are sent to the golgi apparatus where they mature. The apparatus “polishes” the immature proteins, repackages them, and they leave ready for use. (senior year)

Mitochondria

• In the mitochondria food molecules are converted into energy.

• Contains organelle DNA.

Chloroplast

• In plant cells, the chloroplast collects sunlight and converts this into chemical energy.

• Contains organelle DNA.

Lysosomes

• A lysosome is a specialized vacuole that contains enzymes used to clean up cell waste and breakdown large waste molecules into small usable molecules. (maintenance and janitorial)

Vaculoles

• Cell storage. Plant cells contain a large water vacuole used for supporting heavy flowers and leaves.

Cytoskeleton

• A network of protein filaments that provide structure and shape to the cell. Some cytoskeletons also provide movement for some cells.

Cell Membrane

• A lipid bi-layer!!!!

Cell Membrane

Phophate GroupPhophate Group

Fatty AcidFatty Acid ChainsChains

Protein ChannelsProtein Channels

Cell Wall

• Found in plant cells.• Strong outer wall.• Allows for the vertical growth of plants (think

trees!)

Homework

Due Tomorrow• Look up the terms osmosis and diffusion and put

the words and definitions into your notes.• Write one paragraph comparing and contrasting

Eukaryotic cells with Prokaryotic cells.