it all started with an invention…
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It all started with an invention…. The first microscope Sacharias Jansen, 1595, Middleburg, Holland It launched great leaps in Astronomy and Biology. Some of the first great observations with it were made by…. Robert Hooke (1635-1703). Designed microscopes Discovered and documented - PowerPoint PPT PresentationTRANSCRIPT
It all started with an invention….• The first microscope
– Sacharias Jansen, 1595, Middleburg, Holland
– It launched great leaps in Astronomy and Biology.
– Some of the first great observations with it were made by…
Robert Hooke (1635-1703)
– Designed microscopes
– Discovered and documented
the first “cells” in 1665• Named them after the
cells in which a monk sleeps.
From: http://www.ucmp.berkeley.edu/history/hooke.html
Antony van Leeuwenhoek (1632-1723)
A tradesman from Holland who became fascinated with Hooke’s bookDiscovered bacteria, protists, sperm
cells, blood cells, nematodes, etc.Became an expert lens grinder and
made over 500 simple microscopesAcute eyesight and lens grinding
skill let him build microscopes that were capable of 200X magnification
Cell Theory1838 Mattias Schleiden stated that
all plant tissues consisted of cells1839 Theodore Schwann stated that
all animal tissues consisted of cellsEach conjectured that there was a
nucleus1858 Rudolf Virchow combined the
two ideas and added that all cells come from pre-existing cells, formulating the Cell Theory
Rudolf Virchow 1858
Cell Theory• All living things are
composed of one or more cells
• In organisms, cells are the basic units of structure and function.
• All cells are produced only from existing cells.
Prokaryotic vs Eukaryotic Cells
Prokaryotic Cells primitive, ‘before kernal’
- NO NUCLEUS Lack internal membranes (no “membrane-bound” organelles) Genetic material: single, circular DNA molecule suspended in the cytoplasm
Ex. Bacteria (such as Anthrax or E. coli)
Microscopic, single-celled organisms
Prokaryotic Cells (Bacteria)
Unicellular (one) vs. Multicellular (many)Unicellular: Single-Celled Most common forms of
life on Earth. Carry out all functions
of Life. Bacteria Amoeba Paramecium
Unicellular (one) vs. Multicellular (many)Multicellular Larger organisms. Different cells have
specialized functions, together making a complete organism. Human Spider Jellyfish
Visit a “Tour of the Cell” at:video
Cell Membrane: “Security Gate” Surrounds the cell Controls movement of
materials into and out of cell
Nucleus: Controls the functions of the
cell (the brain) Includes the following:
Nuclear Envelope (Membrane): Controls movement into and out of the nucleus
Nuclear Pore: holes where movement takes place
Nucleus:
Nucleolus: Dark area inside nucleus, believed to be for making RNA and ribosomes
Chromatin: Genetic Material (DNA) which is organized into structures called chromosomes during cell division.
Cytoplasm:
remainder of the contents of the cell consisting of: Cytosol:liquid
environment Cytoskeleton: network
of protein fibers that supports the shape of the cell and anchors its organelles and serves as a “track” for them to move on. Crisscrosses the cytoplasm
Mitochondria: “Powerhouse”
Provides energy for cell. Converts food to usable energy for cell.
Have their own ribosomes and DNA.
Golgi Apparatus (Complex): “packaging and distributing center”
Stack of membrane-enclosed spaces. Process/Sorts/Packages protein/lipids for distribution within the cell
and export out of the cell. Proteins/lipids come from endoplasmic reticulum.
Endoplasmic Reticulum (ER): (Highway) Set of
channels…aids in movement of molecules inside the cell.
Rough ER: Ribosomes found on
surface. Smooth ER:
No ribosomes on surface.
Ribosome (4d):
(Factory) Makes proteins and is found in the cytosol or on the ER.
Vacuole: “Storage Tanks”
Fluid filled sack. Stores water, food
molecules, ions and enzymes.
Animal cells contain many small vacuoles.
Plant cells contain a large central vacuole…we will be talking about this more later…
Lysosomes: “Suicide Sacs/Recycling Centers”
Carry enzymes to destroy cellular waste. Break down damaged/worn
out cell parts. Engulf/digest targeted molecules
Defend cell from invading bacteria/viruses
Once thought to be only in animal cells, but exist minimally in plant cells.
Membrane protects cell from enzymes.
Plant Cell
Plant Cells:
Cell Wall: Gives cells shape and
support and provides protection.
Found in algae, fungi and most bacteria too.
contain all of the previous organelles (except centrioles) as well as:
Plant Cells:
Chloroplast: (green) Changes sun’s energy into
food. Also in green algae.
contain all of the previous organelles (except centrioles) as well as:
Plant Cells:
Central Water Vacuole: Single, large water filled
vacuole in the middle of the cell.
Strengthen cells and provide support for plant.
Contains toxins to harm plant predators, waste products and pigment for color (petals).
contain all of the previous organelles (except centrioles) as well as:
Animal Cell
Animal Cells contain all of the previous organelles plus:
Centrioles: 2 cylindrical organelles (together called a centrosome)
Formed by hollow protein fibers called microtubules (part of the cytoskeleton)
Produce microtubules that aid in moving chromosomes during cell division.
Found in animals and algae only but not in all animal cells.
Video tour of cell