Cells Chapter 7

cell – basic unit of all organisms

I. History A.Before microscopes -diseases thought to be caused by magic B. After microscopes -Robert Hooke – scientist who first observed cells -he looked at cork (dead bark) -saw geometric compartments and called them “cells”

II. Cell Theory A.All organisms are composed of one or more cells. B.The cell is the basic unit of structure and organization in all organisms. C.All cells come from preexisting cells.

III. Microscopes A.compound light microscope – uses light and a series of lenses to magnify objects in steps - up to 1500X magnification

III. Microscopes… B.electron microscope – uses a beam of electrons to magnify objects - up to 500,000X magnification - 3D possible -view structures within cells

IV. Cell Types A.Prokaryotic cells - have no nuclei -have no membrane-bound organelles -ex. bacteria; called “prokaryotes”

nucleus – control center of the cell; the central membrane-bound organelle that manages or controls cell functions organelles – small, specialized structures within the cell

IV. Cell types… B.Eukaryotic cells -have nuclei -have membrane-bound organelles -ex. people, all animals and plants called “eukaryotes”

Video: Unicellular organisms tdc02/sci/life/stru/singlecell/index.html tdc02/sci/life/stru/singlecell/index.html

Cell membrane Found in: All cells Function: –Protection –Controls what enters and leaves the cell

Cell wall Found in: Plant cells (and fungi & some bacteria) Function: –Protection, support

Nucleus Found in: All cells except prokaryotes Function: –Controls cell activities –Contains the genetic material of the cell

Nucleolus Found in: All cells except prokaryotes Function: –Found in cell’s nucleus –Make ribosomes

Ribosome Found in: All cells Function: –Makes proteins for the cell

Endoplasmic Reticulum (ER) Found in: All cells except prokaryotes Function: –Folded membrane that carries material within the cell

Golgi apparatus Found in: All cells except prokaryotes Function: –Packages proteins and ships them around the cell

Mitochondrion Found in: All cells except prokaryotes Function: –Breaks down glucose to release energy

Chloroplast Found in: Plant cells (and some others, too) Function: –Photosynthesis

Vacuole Found in: All cells (larger in plant cells) Function: –Store food and wastes

Lysosome Found in: Animal and plant cells Function: –Digest old cell parts

Cytoplasm Found in: All cells Function: –Gel-like fluid inside cell –Protects organelles and keeps them in place