Cell Structure & Function http://koning.ecsu.ctstateu.edu/cell/cell.html

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.

Definition of Cell A cell is the smallest unit that is capable of performing life functions.

Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell

Two Types of Cells Prokaryotic Eukaryotic

Prokaryotic No membrane bound organelles No nucleus (the DNA floats in the cytoplasm) Few internal structures One-celled organisms, Bacteria http://library.thinkquest.org/C004535/prokaryotic_cells.html

Eukaryotic Contain organelles surrounded by membranes Has DNA enclosed in a nucleus Most living organisms Ex: Plants Animals Protists and Fungi Plant Animal http://library.thinkquest.org/C004535/eukaryotic_cells.html

“Typical” Animal Cell http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif

“Typical” Plant Cell http://waynesword.palomar.edu/images/plant3.gif

Structures in the cell with a specific function Cell Parts Organelles Structures in the cell with a specific function

Surrounding the Cell

#4 Cell Membrane Outer membrane of cell that controls movement in and out of the cell Separates cell from environment “Gatekeeper” http://library.thinkquest.org/12413/structures.html

#5. Cell Wall Most commonly found in plant cells & bacteria Supports & protects cells Non-living. Made of cellulose http://library.thinkquest.org/12413/structures.html

Inside the Cell

#3. Nucleus with nuclear membrane Directs cell activities Separated from cytoplasm by nuclear membrane Contains genetic material – DNA The “Control Center”

Nuclear Envelope or Nuclear Membrane Surrounds and protects nucleus Made of two layers Openings allow material to enter and leave nucleus “Mini Gate Keeper” http://library.thinkquest.org/12413/structures.html

#11. DNA-Chromatin (relaxed) or Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics http://library.thinkquest.org/12413/structures.html

#1. Cytoplasm Gel-like mixture that holds the organelles in the cell Surrounded by cell membrane “Jello”

#10. Endoplasmic Reticulum Moves materials around in cell Cavities connected to nuclear envelope Smooth type: lacks ribosomes Rough type (pictured): ribosomes embedded in surface “Subway System” http://library.thinkquest.org/12413/structures.html

#8. Ribosomes Each cell contains thousands Make proteins Found on ER & floating throughout the cell “The Protein Factories” http://library.thinkquest.org/12413/structures.html

#2. Mitochondria Produces energy (ATP) through cellular respiration – breaking down fats & carbohydrates (glucose) “The Powerhouse” http://library.thinkquest.org/12413/structures.html

#7. Golgi Bodies or Golgi Apparatus Protein 'packaging plant' Packs proteins so they can be sent out of the cell “Fed Ex” or “Packers” http://library.thinkquest.org/12413/structures.html

#9. Lysosome Digestive 'plant' for proteins, fats, and carbohydrates Digest proteins and worn out parts of the cell “Digestive System” or “Clean-up Crew” Mainly in animal cells http://library.thinkquest.org/12413/structures.html

#6. Vacuoles Membrane-bound sacs for storing food, water, and waste Very large in plant cells. Smaller in animal cells Help plants maintain shape “Storage tank” http://library.thinkquest.org/12413/structures.html

#12. Chloroplast Usually found in plant cells Contains green pigment ‘chlorophyll’ that traps energy from the sun Where photosynthesis takes place http://library.thinkquest.org/12413/structures.html