1. Cell Structure and Function
Department of Biolgoy, WCU

2. Cells Variation: shape, size and function (blood, fat, nerve)
Common features
nucleus, cytoplasm, membrane

3. Cell structure

4. Plasma membrane Lipid bilayer (water impermeable)
Head (polar), tail (non-polar)
Hydrophilic
Hydrophobic
Glycolipids
Cholesterol

5. Proteins Integral Peripheral Cytoskeleton
transport (1. binding, 2. channels)
Peripheral
Enzymes, cell division
Cytoskeleton
support

6. Membrane specializations
1. Microvilli
finger-like projections
Function
increase surface area
kidney, intestine

7. Molecule passage Absorption - plasma membrane
Secretion - plasma membrane
Intercellular spaces

8. Membrane specializations
2. Membrane junctions
Tight junction (kidney)
Desomosome (muscle cell)
Gap junction (nerve)

9. Cytoplasm Definition (not the nucleus) Components organelles cytosol
inclusions

10. Organelles “Cell is body, organelles are organs” Bound by membranes
Functions
maintain internal environment
prevent enzyme leaching

11. Organelles 1. Mitochondria density indicates activity 2 membranes
Sugar + O2 CO2 + H2O + ATP
DNA and RNA

12. Organelles 2. Ribosomes Protein + RNA (rRNA) Types free ribosomes
polyribosomes
membrane-bound ribosomes (RER)

13. Organelles
3. Endoplasmic reticulum
Types
RER, SER

14. Endoplasmic reticulum
RER functions
protein secretion (export)
protein, phospholipid, cholesterol
SER functions
steroids (estrogen, testosterone)
chemical detoxification
muscle contraction (Ca++)

15. Organelles 4. Golgi apparatus Structure: membrane sacs
Function: protein modification and packing for export

16. Organelles 5. Lysosome Structure Function spherical bags
“garbage disposal”
accumulate H+
endocytosis (bacteria, toxins)

17. Organelles 6. Centrioles Structure Function
barrel-shaped bodies (9 triplet)
Function
mitotic spindle formation

18. Organelles 7. Nucleus - control center Structure Function
nuclear envelope + pore
nucleolus
chromatin - DNA
Function
production of DNA