Cells

Leeuwenhoek made a simple microscope (mid 1600s) magnified 270X Early microscope lenses made images larger but the image was not clear

Leeuwenhoek's Microscope

A) a screw for adjusting the height of the object being examined B) a metal plate serving as the body C) a skewer to impale the object and rotate it D) the lens itself, which was spherical

CELL THEORYA theory resulting from many scientists observations & conclusions

SchwannSchleidenVirchow

CELL THEORY 1. The basic unit of life is the cell. (Hooke)In 1665, an English scientist named Robert Hooke made an improved microscope and viewed thin slices of cork viewing plant cell wallsHooke named what he saw "cells"

CELL THEORY 2. All living things are made of 1 or more cells.Matthias Schleiden (botanist studying plants) Theodore Schwann (zoologist studying animals) stated that all living things were made of cells Schleiden Schwann

CELL THEORY 3. All cells divide & come from old cells. (Virchow)Virchow

MODERN MICROSCOPES A microscope is simple or compound depending on how many lenses it contains A lens makes an enlarged image & directs light towards you eye

A simple microscope has one lens

Similar to a magnifying glass

Magnification is the change in apparent size produced by a microscope

COMPOUND MICROSCOPEA compound microscope has multiple lenses (eyepiece & objective lenses)

STEREOMICROSCOPEcreates a 3D image

TOTAL MAGNIFICATIONPowers of the eyepiece (10X) multiplied by objective lenses determine total magnification.

ELECTRON MICROSCOPES More powerful; some can magnify up to 1,000,000XUse a magnetic field in a vacuum to bend beams of electronsImages must be photographed or produced electronically

Scanning Electron Microscope (SEM)Electron microscope image of a spider produces realistic 3D image only the surface of specimen can be observed Electron microscope image of a fly foot

Transmission Electron Microscope (TEM) produces 2D image of thinly sliced specimendetailed cell parts (only inside a cell) can be observed

Scanning Tunneling Microscope (STM) able to show arrangement of atoms

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

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

Examples of CellsAmoeba proteusPlant StemRed Blood CellNerve CellBacteria

Two Types of CellsProkaryoticEukaryotic

ProkaryoticDo not have structures surrounded by membranesFew internal structuresOne-celled organisms, Bacteria

http://library.thinkquest.org/C004535/prokaryotic_cells.html

EukaryoticContain organelles surrounded by membranesMost living organisms

PlantAnimalhttp://library.thinkquest.org/C004535/eukaryotic_cells.html

Typical Animal Cellhttp://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif

http://waynesword.palomar.edu/images/plant3.gifTypical Plant Cell

Cell PartsOrganelles

Surrounding the Cell

Cell MembraneOuter membrane of cell that controls movement in and out of the cellDouble layer http://library.thinkquest.org/12413/structures.html

Cell WallMost commonly found in plant cells & bacteriaSupports & protects cells

http://library.thinkquest.org/12413/structures.html

Inside the Cell

Nucleus Directs cell activitiesSeparated from cytoplasm by nuclear membraneContains genetic material - DNA

Nuclear MembraneSurrounds nucleusMade of two layersOpenings allow material to enter and leave nucleus http://library.thinkquest.org/12413/structures.html

ChromosomesIn nucleusMade of DNAContain instructions for traits & characteristics


NucleolusInside nucleusContains RNA to build proteins http://library.thinkquest.org/12413/structures.html

CytoplasmGel-like mixtureSurrounded by cell membraneContains hereditary material

Endoplasmic ReticulumMoves materials around in cellSmooth type: lacks ribosomesRough type (pictured): ribosomes embedded in surface http://library.thinkquest.org/12413/structures.html

RibosomesEach cell contains thousandsMake proteinsFound on ER & floating throughout the cellhttp://library.thinkquest.org/12413/structures.html

MitochondriaProduces energy through chemical reactions breaking down fats & carbohydratesControls level of water and other materials in cellRecycles and decomposes proteins, fats, and carbohydrateshttp://library.thinkquest.org/12413/structures.html

Golgi BodiesProtein 'packaging plant'Move materials within the cellMove materials out of the cellhttp://library.thinkquest.org/12413/structures.html

LysosomeDigestive 'plant' for proteins, fats, and carbohydratesTransports undigested material to cell membrane for removalCell breaks down if lysosome explodes http://library.thinkquest.org/12413/structures.html

VacuolesMembrane-bound sacs for storage, digestion, and waste removalContains water solutionHelp plants maintain shape


ChloroplastUsually found in plant cellsContains green chlorophyllWhere photosynthesis takes placehttp://library.thinkquest.org/12413/structures.html

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Cells