1. Structure and Function of the Cell Chapter 4

2. 4.1 Discovering the cell…   1665 – Hooke looked at plants under the microscope and saw little boxes – –He named them “cells”   1673 – Van Leeuwenhoek was the first to see living cells

3. Fast Forward…150 years!   Schleiden – all plants are composed of cells  – all animals are composed of cells  Schwann – all animals are composed of cells  – cells come only from other cells  Virchow – cells come only from other cells  These three scientists’ work lead to the modern CELL THEORY

4. The Cell Theory   1. All living things are composed of cells   2. Cells are the basic unit of an organism   3. Cells only come from the reproduction of preexisting cells.

5. Cell Diversity Red Blood Cells Bacterial Cells Parasitic CellUlcer causing bacteria cells

6. Your body has over 200 different types of cells!

7. Cell Size Most cells are microscopic Cell size is limited by the surface area to volume ratio

8. Cell Shape  Shape is determined by the function of the cell

9. Internal Organization  Prokaryotic Vs. Eukaryotic Cells “Before Nucleus” No Nucleus or Membrane organelles Single cell organisms “True Nucleus” Yes Nucleus and Membrane organelles Multicellular and single Cell organisms

10. Surface Area to Volume Ratio  Surface Area : L x W x # of sides  Volume: L x W x H  Ratio : surface area/volume

11. Now you try…. 1. Obtain a copy of the lab: Modeling Cells: Surface Area to Volume AND box paper 2. Cut out boxes and tape them together (3 boxes total) 3. Complete lab worksheet about surface area to volume ratio

12. All Eukaryotic Cells Have… 1. A cell membrane 2. A nucleus 3. Other organelles

13. Parts of the Eukaryotic Cell The structures are determined by the functions of each part

14. 1. Cell Membrane  Function: outer layer of a cell that allow substances into and out of the cell  Selectively permeable – allows only certain things to cross the membrane

16. Parts of the Membrane   Membrane Lipids – –Phospholipids arranged due to their hydrophobic and hydrophilic ends – –Lipid bilayer – –Steroid (cholesterol) embedded within

17. Parts of the Membrane (cont)  Membrane Proteins –Peripheral proteins – attached to either side of the cell membrane –Integral proteins – embedded within the cell membrane and extends out on both sides

18. Fluid Mosaic Model  Membrane behaves like a liquid –Lateral movement of lipids and proteins  Mosaic – changing pattern of proteins and lipids in the membrane

19. Organelles Organelles  “Mini organs” of the cell  Each organelle has its own structure and function  All cells have different types and numbers of organelles

20. Nucleus Nucleus  Function: to store the hereditary information of the cell (DNA) and to control the cell  Contains: nuclear envelope, nuclear pores, nucleolus, and chromatin (chromosomes)

21. Mitochondria  Function: makes ATP  “Powerhouse of the Cell”

22. Rough Endoplasmic Reticulum  Function: Makes proteins, glycoproteins, and membranes for export out of the cell  Covered in ribosomes

23. Smooth Endoplasmic Reticulum  Function: Makes lipids, metabolizes carbohydrates, and detoxification center for the cell

24. Ribosomes  Function: Protein synthesis  Attached to E.R. or free in cytoplasm  Made in nucleus and completed in cytoplasm

25. Golgi Apparatus  Function: Manufacturing, warehousing, sorting, and shipping materials out of the cell

26. Lysosomes  Function: Digests (breaks down) macromolecules the are in the cell, such as proteins and carbs.  Also breaks down dead cells

27. Peroxisomes  Function: Breaks down fatty acids  Detoxification center in liver cells

28. Cytoskeleton  Function: Support system of the cell, aid in movement within the cell  3 Structural Types: microtubules microtubules microfilaments microfilaments intermediate filaments intermediate filaments

29. Cytoplasm  Function: Holds organelles in the cell  Site of all chemical reactions in cell

30. Cilia and Flagella  Function: Locomotion and movement of materials around the cell  Animal cells only

31. Cell Wall  Function: Protects the cell, gives the cell shape and structural support  Plant cells

32. Chloroplasts  Function: Photosynthesis  Makes energy from the sun  In plant cells

33. Central Vacuole  Function: Stores materials especially water and waste products  In plant cells