Parts of a Eukaryotic Cell

Cell Theory 1) All living things are made up of cells. 2) Cells are the smallest working units of all living things. 3) Cells come from other cells There are two types of cells: Prokaryotic Eukaryotic

Prokaryotic One-celled No nucleus DNA looks like a twisted rubber band Do NOT have membrane-covered organelles All have a cell wall outside the cell membrane Ex: Bacteria

Eukaryotic Larger Have a nucleus Do have membrane-covered organelles Some (plants) have a cell wall Animal Plant

Two Types of Eukaryotic Cells Animal cells Plant cells

“Typical” Animal Cell

“Typical” Plant Cell

Cell Parts Organelles

The Cell . . . The School Think of the cell as a tiny, little school Just like a school has different things (buildings, people, items) that make it function (work), so does the cell. In the cell, organelles are the things that make the cell work.

Organelles “little organs” Have specific jobs that help keep the cell alive Like the organs in your body have specific jobs to help keep you alive

Surrounding the Cell

← Cell Wall Stiff outer layer that supports & protects the cell All plant cells have a cell wall that is made of a sugar called “cellulose” (All prokaryotic cells, like bacteria, also have cell walls) Animal cells do not have cell walls Like a brick wall around a school ←

Cell Membrane Every cell has a cell membrane Like a wire fence around a school Surrounds & protects the cell Controls what goes in and out of cell Allows nutrients and water in Lets waste go out

Inside the Cell

Nucleus Only in eukaryotic cells The “brain” or “control center”; directs all activites Like the office at a school Large, dark, sometimes in center Contains genetic material – DNA (= the principal) Covered by two membranes which allow materials to go in and out

Proteins Not THIS kind of protein! Control the chemical reactions in the cell The messages of how to make proteins are given by the DNA (principal) Like the educated students at a school Not THIS kind of protein!

→ Ribosomes Smallest organelles in cell Each cell contains thousands Like the teachers at a school Makes protein (= educated students) Found floating inside cell Or attached to membranes or organelles Found in BOTH prokaryotic and eukaryotic cells →

Endoplasmic Reticulum (ER) Membranes with many folds Part of the cell’s transport & delivery system: folds have passageways = move materials around cell Like the hallways at a school Two types: Smooth ER: no ribosomes Rough ER: ribosomes attached

Mitochondria Main power source of the cell Makes energy by breaking down sugar (food) Like the cafeteria of a school Energy is stored in molecule called ATP Has its own DNA that is different from the cell’s DNA

Chloroplasts Usually found in plant and algae cells Like solar-powered energy generators at a school Contain green chlorophyll = traps the energy of sunlight Where photosynthesis takes place (Sun + CO2 + H2O  O2 + sugar)

Golgi Complex Packages & delivers materials within and out of the cell The “Post Office” of the cell Like the staff room (with teachers’ boxes) at a school

Lysosomes Responsible for cleaning cell Like the janitors at a school Destroy worn-out or damaged organelles Get rid of wastes Protect cell from harmful products Like the janitors at a school Material is enclosed in a vessicle Lysosome bumps into vessicle and pours enzymes into it (breaks down what’s inside of it)

Vacuoles Storage site for cell In plants: large vacuole in center of cell store water, which helps plants keep their shape Plants wilt when vacuoles lose water Like the underground water tanks at a school