What are Cells All living things have cells

What are Cells? All living things have cells, the basic unit of an organism

Two Types Prokaryotic cells - do not have a nucleus or other membrane-bound organelles. Eukaryotic cells - have a nucleus and other membrane-bound organelles

Cell Parts and Functions Cell Wall Rigid layer of nonliving material Surrounds the cells of plants and some other organisms. Helps protect and support the cell Water, oxygen, and other materials can pass through easily. Cell Membrane All cells have membranes Controls what substances come into and out of the cell Nucleus Large oval structure Directs all the cell’s activities (control center)

Nuclear Envelope (Membrane) Membrane that protects the nucleus Allows materials to pass in and out of the nucleus Chromatin Thin strands floating in the nucleus Contain genetic material, instructions for directing the cell’s functions Nucleolus Small round structure within nucleus Produces ribosomes Cytoplasm Found within the cell membrane Clear, thick gel-like fluid that is constantly moving Organelles are found floating within

Mitochondria Rod-shaped organelles Convert energy in food molecules to energy the cell can use to carry out its functions Endoplasmic Reticulum (ER) Organelle which is made up of a maze of passageways Carry proteins and other materials from one part of the cell to another Ribosomes Small, grain-like bodies Some attached to the endoplasmic reticulum others float in the cytoplasm Produce proteins

Golgi Bodies Flattened sacs and tubes Receive proteins and other newly formed materials from the ER, package them, and distributes them to other parts of the cell Also release materials outside of the cell Lysosomes Small, round organelles Contain chemicals to break down certain materials in the cell (Breaks down large food particles and old cell parts) Releases broken down substances so they can be used

Chloroplasts Large green organelles Found in plant cells and some other organisms Capture energy from the sun and use it to produce food for the cell Chlorophyll inside gives it its green color Vacuole Water-filled sac Storage areas for cells Stores food and other materials needed by the cell Can also store waste products Plant Cells: have one large vacuole Some animal cells have smaller vacuoles

Bacteria Cell Much smaller than plant or animal cells Has a cell wall and cell membrane Does NOT contain a nucleus Genetic material (looks like tangled string) is found floating in the cytoplasm. Does contain ribosomes, but no other organelles found in plant or animal cells