Cell Structure & Function
A Little History 1600’s – cork cells – Robert Hooke
Anton van Leeuwenhoek-1600’s Observed “animalcules”
Anton’s Words . . . my work, which I've done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge, which I notice resides in me more than in most other men. And therewithal, whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof. Antony van Leeuwenhoek. Letter of June 12, 1716
Matthias Schleiden – 1800’s Plant Biologist – started as lawyer Father of cell theory One of first German scientists to accept Darwin’s theory of Evolution
Theodor Schwann -1800’s Medicine – physiology Met with Schleiden Helped with cell theory after realizing that nucleus was in both plant and animal cells
Rudolf Virchow – 1800’s Studied cell division Completed cell theory
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.
Janet Plowe – 1900’s Showed that the cell membrane is an actual structure
George Langford - now Studied movement of vesicles along the cytoskeleton Both myosin tubules and actin filaments
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
Sizes of cells (Click)
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
“Typical” Plant Cell http://waynesword.palomar.edu/images/plant3.gif
Structures/Organelles Cell Parts Structures/Organelles
Cell Membrane Outer membrane of cell that controls movement in and out of the cell Double layer
Cell Wall Most commonly found in plant cells & bacteria Supports & protects cells
Nucleus Directs cell activities Separated from cytoplasm by nuclear membrane Contains genetic material - DNA
Nuclear Membrane Surrounds nucleus Made of two layers Openings allow material to enter and leave nucleus
Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics http://library.thinkquest.org/12413/structures.html
Nucleolus Inside nucleus Contains RNA to build proteins
Cytoplasm Gel-like mixture filled with proteins Surrounded by cell membrane
Rough Endoplasmic Reticulum Moves materials around in cell ribosomes embedded in surface New proteins are twisted and folded
Smooth Endoplas-mic Reticulum No ribosomes Synthesize lipids Site for enzyme action Storage of enzymes
Ribosomes Each cell contains thousands Make proteins Found on ER & floating throughout the cell
Mitochondria Produces energy through chemical reactions – breaking down fats & carbohydrates Controls level of water & other materials in cell Recycles and decomposes proteins, fats, and carbohydrates
Golgi Bodies Protein 'packaging plant' Move materials within the cell Move materials out of the cell
Cytoskeleton Composed of proteins Movement of vesicles Support for cell Cilia, flagellae, cell division
Lysosome Digestive 'plant' for proteins, fats, and carbohydrates Transports undigested material to cell membrane for removal Cell breaks down if lysosome explodes
Peroxisome Oxidative enzymes - catalase Self- replicating Do not form at Golgi Body Rid body of toxins such as hydrogen peroxide
Vacuoles – vesicles Digestion Secretion Transport Water - vacuole
Vacuoles – in Plants Membrane-bound sacs for storage, digestion, and waste removal Contains water solution Help plants maintain shape
Chloroplast - Plant Where photosynthesis takes place Contains chlorophyll Found in plants, protists
Centrosome/Centrioles - Animal Involved in cell division – formation of spindle Microtubule Organizing Center