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

History 1630s- First microscope was invented 1665- Robert Hooke observed a thin piece of cork under a microscope Called the tiny compartments “cells” like the small rooms monks live in 1675- Anton van Leeuwenhook observed living organisms from a sample of pond water Called them animalcules or “tiny animals”

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. 3

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

Number of Cells Organisms may be: Unicellular – composed of one cell Multicellular- composed of many cells that may organize

Prokaryotic Eukaryotic Two Types of Cells Prokaryotic Eukaryotic

Prokaryotic Do not have structures surrounded by membranes Few internal structures One-celled organisms, Bacteria http://library.thinkquest.org/C004535/prokaryotic_cells.html

Eukaryotic Contain organelles surrounded by membranes Most living organisms Plant Animal http://library.thinkquest.org/C004535/eukaryotic_cells.html

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

Different kinds of animal cells white blood cell red blood cell cheek cells sperm nerve cell muscle cell Amoeba Paramecium

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

Different kinds of plant cells Onion Epidermal Cells Root Hair Cell root hair Guard Cells

Cell Parts Organelles

Organelles Very small size Can only be observed under a microscope Have specific functions Found throughout cytoplasm

Surrounding the Cell

Cell Wall Found in plant cells & bacteria Supports & protects cells “THE WALL” http://library.thinkquest.org/12413/structures.html

Cell Membrane Outer membrane Controls movement in and out of the cell Made of phospholipids “THE GATEKEEPER” http://library.thinkquest.org/12413/structures.html

Inside the Cell

Cytoplasm Gel-like mixture Surrounded by cell membrane Suspends the organelles

Nucleus Controls cell activities Separated from cytoplasm by nuclear membrane Contains genetic material – DNA “THE BOSS”

Nuclear Membrane Surrounds nucleus Protects genetic material Nuclear Pores: Openings allow material to enter and leave nucleus “THE GUARDIAN” http://library.thinkquest.org/12413/structures.html

Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics “THE BLUEPRINTS” http://library.thinkquest.org/12413/structures.html

Nucleolus Inside nucleus Manufactures ribosomes http://library.thinkquest.org/12413/structures.html

Endoplasmic Reticulum Transportation system within the cell Smooth type: lacks ribosomes Rough type (pictured): ribosomes embedded in surface, transports protein “THE HIGHWAY” http://library.thinkquest.org/12413/structures.html

Ribosomes Make proteins Each cell contains thousands Found on Rough ER & floating in cytoplasm “PROTEIN FACTORIES” http://library.thinkquest.org/12413/structures.html

Mitochondria Produces energy through chemical reactions – breaking down fats & carbohydrates “POWERHOUSE” http://library.thinkquest.org/12413/structures.html

Golgi Bodies ‘Packaging plant‘ for materials Move materials within the cell Move materials out of the cell “UPS GUY” http://library.thinkquest.org/12413/structures.html

Lysosome Digestive 'plant' Transports digested material to cell membrane for removal Cell breaks down if lysosome explodes “GARBAGE MAN” http://library.thinkquest.org/12413/structures.html

Vacuoles Membrane-bound sacs for storage Contains water solution Help plants maintain shape “WATER BALLOONS” http://library.thinkquest.org/12413/structures.html

Chloroplast Found in plant cells Contains green chlorophyll Where photosynthesis takes place “GREEN GUYS” http://library.thinkquest.org/12413/structures.html

Aid the cell in division “CHURROS” Centrioles Found in animal cells In pairs Aid the cell in division “CHURROS” http://library.thinkquest.org/12413/structures.html 32

Provide support in animal & plants Made of protein Cytoskeleton Provide support in animal & plants Made of protein http://library.thinkquest.org/12413/structures.html 33

Differences between plant cells and animal cells Relatively smaller in size Relatively larger in size Irregular shape Regular shape No cell wall Cell wall present

Differences between Plant Cells and Animal Cells Vacuole small or absent Large central vacuole Nucleus in center of cell Nucleus pushed to side of cell Mitochondria for energy Mitochonria & Chloroplasts

Similarities between plant cells and animal cells Both have a cell membrane surrounding the cytoplasm Both have a nucleus Both contain mitochondria

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