Introduc)on  to  Cells  

Defini)on  of  Cell  

A  cell  is  the  smallest  unit  that  is  capable  of  performing  life  

func4ons.  

Cells  are  alive.    

Examples  of  Cells  

Amoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

Cell  Theory  

•  All  living  things  are  made  up  of  cells.    •  Cells  are  the  smallest  working  units  of  all  living  things.    

•  All  cells  come  from  preexis4ng  cells  through  cell  division.    

Who  came  up  with  this  theory?  

1.  Ma>hias  Schleiden  (1838)  All plants are made of cells!

Onion skin cells

2.  Theodor  Schwann  

Who  came  up  with  this  theory?  All animals are made of cells!

Human red blood cells

Who  came  up  with  this  theory?  

3.  Rudolf  Virchow    

All cells come from pre-existing

cells!

Two  Types  of  Cells  

• Prokaryo)c  • Eukaryo)c  

Prokaryo)c  

•  Do  not  have  structures  surrounded  by  membranes  

•  Few  internal  structures  

•  One-­‐celled  organisms,  Bacteria    

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

Eukaryo)c  •  Contain  organelles  surrounded  by  membranes  

•  Most  living  organisms  

Plant Animal

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

Cell  Structure    &  Func)on  

http://koning.ecsu.ctstateu.edu/cell/cell.html

1. Cell Membrane

2. Cytoplasm

3. Nuclear Membrane

8. Smooth Endoplasmic Reticulum

6. Flagella 10. Mitochondria

4. Nucleolus

12. Nucleus 9. Rough Endoplasmic Reticulum

5. Golgi apparatus

13. Vacuole

7. Ribosome

11. Lysosome

14. Microtubules

1. Cell Membrane

2. Cytoplasm

3. Nuclear Membrane

8. Smooth Endoplasmic Reticulum

10. Mitochondria

4. Nucleolus

12. Cell Wall

9. Rough Endoplasmic Reticulum

5. Golgi apparatus

6. Vacuole

7. Ribosome

11. Chloroplast

2. Cytoplasm

13. Microtubules

Cell  Parts  

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  

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

Nucleus    

•  Directs  cell  ac4vi4es  •  Separated  from  cytoplasm  by  nuclear  membrane  

•  Contains  gene4c  material  -­‐  DNA  

Nuclear  Membrane  

•  Surrounds  nucleus  •  Made  of  two  layers  •  Openings  allow  material  to  enter  and  leave  nucleus    

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

Nucleolus  

•  Inside  nucleus  •  Contains  RNA  to  build  proteins    

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

Cytoplasm  

•  Gel-­‐like  mixture  •  Surrounded  by  cell  membrane  

•  Contains  hereditary  material    

Endoplasmic  Re)culum  •  Moves  materials  around  in  cell  

•  Smooth  type:  lacks  ribosomes  

•  Rough  type  (pictured):  ribosomes  embedded  in  surface    

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

Ribosomes  

•  Each  cell  contains  thousands  

•  Make  proteins  

•  Found  on  ribosomes  &  floa4ng  throughout  the  cell  

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

Mitochondria  

•  Produces  energy  through  chemical  reac4ons  –  breaking  down  fats  &  carbohydrates  

•  Controls  level  of  water  and  other  materials  in  cell  

•  Recycles  and  decomposes  proteins,  fats,  and  carbohydrates  

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

Golgi  Bodies  (or  Golgi  Apparatus)  

•  Protein  'packaging  plant'  

•  Move  materials  within  the  cell  

•  Move  materials  out  of  the  cell  

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

Lysosome  •  Diges4ve  'plant'  for  proteins,  fats,  and  carbohydrates  

•  Transports  undigested  material  to  cell  membrane  for  removal  

•  Cell  breaks  down  if  lysosome  explodes    

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

Vacuoles  

•  Membrane-­‐bound  sacs  for  storage,  diges4on,  and  waste  removal  

•  Contains  water  solu4on  •  Help  plants  maintain  shape  

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

Chloroplast  

•  Usually  found  in  plant  cells  

•  Contains  green  chlorophyll  

•  Where  photosynthesis  takes  place  

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

Ostrich  emerged  from  egg