Cells EQ: What are the structures and functions of the different types of cells and cell parts?

Discovery of Cells First cells were discovered by Robert Hooke –Looked at cork cells –No organelles were visible Van Leeuwenhoek looked a living cellular life in pond water –“EEWW this is in the water we drink” Advancement in microscopes lead to the visualization of organelles

Prokaryotic Cells Simple cells No nucleus or complex organelles Mostly bacteria

Eukaryotic Cells Complex cells Have a variety of specialized organelles Genetic information is enclosed in a nucleus Include plant and animal cells

Nucleus Found only in eukaryotes Information center of the cell Contains DNA – genetic information Surrounded by a nuclear envelope which regulates what enters and leaves the nucleus

Nucleolus Assembles the ribosome

Chromatin Granular material within the nucleus Consists of tightly coiled DNA

Ribosomes Assembles proteins Uses the information from the DNA that comes to the ribosome in the form of RNA

Smooth Endoplasmic Reticulum Aka smooth ER Transports material through the cells Can store special enzymes and chemicals for the synthesis of membrane lipids and detoxification of drugs

Rough Endoplasmic Reticulum Aka rough ER Chemically modify the proteins that are exported from the cell made in the ribosome Studded with ribosomes

Golgi Apparatus Modifies, sorts, and packages proteins and other cellular materials for transport out of the cell or storage

Lysosomes Small organelles with enzymes that breakdown lipids, carbohydrates and proteins for use by the cell Also breaks down non- functioning organelles Some human diseases are caused when lysosomes fail

Vacuole Store material like water, salts, proteins, and carbohydrates Single large vacuole in plant cells provide some support for the cell

Mitochondria Convert chemical energy stored in food into compounds that the cell can use The folds increase the surface area which increases the efficiency May have been an independent cell at one time Inherited through the maternal line

Chloroplasts Found only in plant cells Convert the sun’s energy into a type that the cell can use Appear green due to pigments for light absorption May have been an independent cell

Cytoskeleton Protein filaments that support the cell and give the cell shape Used to move chromosomes during mitosis

Cell Membrane Regulates what enters and leaves the cell Provides protection and support for the cell Composed of a lipid bi-layer (two layers of fat)

Cell Wall Found only in plants Porous to allow material in and out Provides support and protection for the cell Made of cellulose – tough carbohydrates

Cytoplasm Cell filler Found between all the organelles

Endosymbiosis Theory About 2 billion years ago membrane bound nuclei appear Prokaryotes began forming symbiotic relationships Symbiosis –A partnership where one or both participants benefit, or one potentially is harmed Eukaryotes came from living communities formed by symbiotic prokaryotes Evidence –membrane bound organelles –Mitochondrial and Chloroplastic DNA

Endosymbiosis Theory Evidence Continued… –Mitochondria and chloroplasts have ribosomes similar to bacterial ribosomes –Mitochondria and chloroplasts reproduce by binary fission while the cell containing them undergoes mitosis