Cell Structure & Function
Cell Theory All living things are made up of cells. Cells are the smallest working units of all living things. All cells come from preexisting cells through cell division.
Cell Theory Scientists Hooke – named cells after viewing cork under a microscope Leeuwenhook – saw living cells and called them “animalcules” Schwann – concluded that animals were made of cells Schleiden – concluded that plants were made of cells Virchow – determined that cells only came from pre-existing cells
Definition of Cell The smallest unit capable of life.
Examples of Cells Amoeba Proteus Plant Stem Red Blood Cell Nerve Cell Bacteria
Two Types of Cells Prokaryotic Eukaryotic
Prokaryotic No membrane bound structures No organelles One-celled organisms, Bacteria
Eukaryotic Contain organelles surrounded by membranes Most living organisms PlantAnimal
“Typical” Animal Cell /~ acarpi/NSC/images/cell.gif
“Typical” Plant Cell
Cell Parts Organelles
Surrounding the Cell
Cell Membrane Outer part of cell that controls movement in and out of the cell Double layer called Phospholipid bilayer
Cell Wall Found in plant cells & bacteria Supports & protects cells
Inside the Cell
Nucleus Directs cell activities Separated from cytoplasm by nuclear membrane Contains DNA
Nuclear Membrane Surrounds nucleus Made of two layers Openings allow material to enter and leave
Chromosomes In nucleus Made of DNA Contain genetic info
Nucleolus Inside nucleus Makes ribosomes
Cytoplasm Gel-like mixture that fills cell Site of some chemical reactions
Endoplasmic Reticulum Moves materials around in cell to assemble proteins Smooth type: lacks ribosomes Rough type (pictured): ribosomes embedded in surface
Ribosomes Each cell contains thousands Make proteins Found on ER & floating throughout the cell
Mitochondria Produces energy through chemical reactions – breaking down fats & carbohydrates Site of cell respiration
Golgi Bodies Protein 'packaging plant' Move materials in and out of the cell
Lysosome Digests worn out parts, proteins, fats, and carbohydrates Cell breaks down if lysosome explodes
Vacuoles Membrane-bound sacs for storage (especially water in plants) Help plants maintain shape
Chloroplast Found in plant cells Contains green chlorophyll Site of photosynthesis