Discovering Cells: Anton van Leeuwenhoek's Revolutionary Microscope

Slide1Discovering Cells… Discovering  Cells…

Slide2Anton van  Leenwenhoek Anton  van  Leenwenhoek  Dutch  scientist  Dutch  scientist  The  first  person  to  look  at  water  using  a single-lens  microscope  in  the  mid-1600’s.  The  first  person  to  look  at  water  using  a single-lens  microscope  in  the  mid-1600’s.  He  was  surprised  to  see the  water  was  full  of living  things:  He  was  surprised  to  see the  water  was  full  of living  things: “animalcules” “animalcules”

Slide3van Leenwenhoek  Microscope van  Leenwenhoek  Microscope

Slide4Robert Hooke Robert  Hooke  English  scientist  English  scientist  Studied  cork  using a  compound  light microscope.  Studied  cork  using a  compound  light microscope.

Slide5Hooke Microscope Hooke  Microscope

Slide6CELLSCELLS  He  observed  tiny geometric  shapes and  named  them “cells”  because they  reminded  him of  the  small  rooms monks  lived  in  at the  monastery.  He  observed  tiny geometric  shapes and  named  them “cells”  because they  reminded  him of  the  small  rooms monks  lived  in  at the  monastery.

Slide7Robert  Hooke published 'Micrographia'  in 1665.  It  is  his most  famous work,  and  is notable  for  the stunning illustrations, drawn  by  Hooke himself.  Robert  Hooke published 'Micrographia'  in 1665.  It  is  his most  famous work,  and  is notable  for  the stunning illustrations, drawn  by  Hooke himself.

Slide8The  picture  of the  flea  shown is  one  of  his most  famous images;  the original  is  18 inches  across.  The  picture  of the  flea  shown is  one  of  his most  famous images;  the original  is  18 inches  across.

Slide9Additional Hooke  drawings Additional  Hooke  drawings

Slide10Matthias Schleiden Matthias  Schleiden  German  scientist  German  scientist  Observed  different plants  and concluded  that  all plants   are composed  of  cells in  the  1830’s.  Observed  different plants  and concluded  that  all plants   are composed  of  cells in  the  1830’s.

Slide11Theodore Schwann Theodore  Schwann  German scientist  German scientist  Made observations that  all  animals are  composed of  cells.  Made observations that  all  animals are  composed of  cells.

Slide12Robert Brown Robert  Brown  Scottish  scientist  Scottish  scientist  Observed  that  all cells  contained  a prominent  structure that  appeared  to  be a  “blob”  in  the center  of  the cell…the  nucleus .  Observed  that  all cells  contained  a prominent  structure that  appeared  to  be a  “blob”  in  the center  of  the cell…the  nucleus .

Slide13Rudolf Virchow Rudolf  Virchow  Concluded  that  the nucleus  was  the structure responsible  for  cell division.  Concluded  that  the nucleus  was  the structure responsible  for  cell division.

Slide14Together, these  men developed  The  Cell  Theory : Together,  these  men developed  The  Cell  Theory :

Slide15The Cell  Theory The  Cell  Theory 1.   All  organisms  are  composed of  one  or  more  cells. 1.   All  organisms  are  composed of  one  or  more  cells. 2.   The  cell  is  the  basic  unit  of organization  of  organisms. 2.   The  cell  is  the  basic  unit  of organization  of  organisms. 3.   All  cells  come  from preexisting  cells. 3.   All  cells  come  from preexisting  cells.

Slide17Compound Light  Microscopes Compound  Light  Microscopes  Uses  2  or  more  glass  lenses  to magnify  objects.  Uses  2  or  more  glass  lenses  to magnify  objects.  Can  magnify  up  to  1500  times.  Can  magnify  up  to  1500  times.

Slide18Compound Light  Microscopes Compound  Light  Microscopes

Slide19Scanning Electron  Microscope Scanning  Electron  Microscope  Sweeps  a  beam  of  electrons  over  the surface  of  a  specimen  causing electrons  to  be  emitted  from  the specimen.  Sweeps  a  beam  of  electrons  over  the surface  of  a  specimen  causing electrons  to  be  emitted  from  the specimen.  Produce  a  realistic,  3D  image…but only  on  the  surface.  Produce  a  realistic,  3D  image…but only  on  the  surface.  Can  magnify  about  60,000  times.  Can  magnify  about  60,000  times.

Slide20Scanning Electron  Microscope Scanning  Electron  Microscope

Slide21Transmission Electron  Microscope Transmission  Electron  Microscope  Aims  a  beam  of  electrons  through a  specimen  Aims  a  beam  of  electrons  through a  specimen  Two-dimensional  images  are used  to  study  details  of  cells  Two-dimensional  images  are used  to  study  details  of  cells  Can  magnify  hundreds  of thousands  of  times.  Can  magnify  hundreds  of thousands  of  times.

Slide22Transmission Electron  Microscope Transmission  Electron  Microscope

Slide23Blood Cells Blood  Cells Compound Microscope TEM SEM

Slide24LOOKING AT  CELLS LOOKING  AT  CELLS  FORM  DEFINES  FUNCTION  FORM  DEFINES  FUNCTION  A  cell’s  shape  reflects  its  function.  A  cell’s  shape  reflects  its  function.  VARIOUS  SHAPES  VARIOUS  SHAPES  Branched  Branched  Flat  Flat  Round  Round  Rectangular  Rectangular  Irregular  Irregular  Change  shapes  Change  shapes

Slide25CELL SIZE CELL  SIZE  Cell  size  is  limited  by  a  cell’s surface  area-to-volume  ratio  Cell  size  is  limited  by  a  cell’s surface  area-to-volume  ratio  Cells  get  larger…need  more nutrients…release  more  waste.  Cells  get  larger…need  more nutrients…release  more  waste.  The  substances  have  to  move farther  to  reach  their  destination  The  substances  have  to  move farther  to  reach  their  destination

Slide26CELL FEATURES CELL  FEATURES (Venn  Diagram?) (Venn  Diagram?)  ALL  cells  share  common structural  features:  ALL  cells  share  common structural  features:  Cell  membrane  Cell  membrane  Cytoplasm  Cytoplasm  Ribosomes  Ribosomes  DNA  DNA

Slide27Two Types  of  Cells Two  Types  of  Cells  Prokaryotes  Prokaryotes  Lacks  a  nucleus  Lacks  a  nucleus  Pro  =  before  Pro  =  before  Karyon  = nucleus  Karyon  = nucleus  Eukaryotes  Eukaryotes  Has  a  nucleus  Eu  =  true  Karyon  = nucleus

Slide28Two Types  of  Cells Two  Types  of  Cells  Prokaryotes  Prokaryotes  Small, simple, single-celled organisms  Small, simple, single-celled organisms  BACTERIA  BACTERIA  Eukaryotes  Eukaryotes  Complex, multi-celled organisms  PLANTS  & ANIMALS

Slide29Two Types  of  Cells Two  Types  of  Cells  Prokaryotes  Prokaryotes  Do  NOT  have:  Do  NOT  have:  Eukaryotes  Eukaryotes  DO  have: Internal  compartments (membrane-bound  organelles) Internal  compartments (membrane-bound  organelles)

Slide30Eukaryotic cells  can  carry  out more  specialized  functions because  of  their  complex organization  (organelles). Eukaryotic  cells  can  carry  out more  specialized  functions because  of  their  complex organization  (organelles).

Slide31DNACell Division Cell Membrane Ribosomes Small,  simple, single-celled organisms Small,  simple, single-celled organisms Nucleus No Nucleus Complex,  multi- celled organisms Complex,  multi- celled organisms No  Internal Compartments— membrane-bound organelles No  Internal Compartments— membrane-bound organelles Has  Internal Compartments— membrane-bound organelles Has  Internal Compartments— membrane-bound organelles Earliest  cells Earliest  cells Smaller ribosomes Smaller ribosomes Larger ribosomes Larger ribosomes Cells  evolved  later Cells  evolved  later Cell  Division— Cell  Division— Binary  Fission Binary  Fission Cell  Division— Cell  Division— Mitosis Mitosis