1. Cell Structure

2. Cell Theory All living organisms are made of one or more cells.
The cell is the basic organizational unit of life.
All cells come from pre-existing cells.
Why study cells? Haven’t we already learned about them?
Most diseases/disorders can be explained due to a default at the cellular level.

3. Cell Characteristics Genetic material
single circular molecule of DNA in prokaryotes
double helix located in nucleus in eukaryotes – nuclear envelope (double membrane
Cytoplasm fills cell interior –
sugars, amino acids,
proteins – organelles
Plasma membrane encloses
the cell – phospholipid bilayer
Phospholipid
Membrane
proteins

4. Generalized Eukaryotic Cell

5. Cell Size
Most cells are relatively small because as size increases, volume increases much more rapidly.
longer diffusion time

6. Visualizing Cells

9. Found in plants, as well as some bacteria, protists, and fungi
Cell Wall
Found in plants, as well as some bacteria, protists, and fungi
Structure
Thicker, stronger, and more rigid than cell membranes
Capable of supporting large plants (e.g., tall trees)
Made up of tiny fibres of cellulose
Perforated with many pores
Function
Protects cell from rupturing
Allows cell to exchange material with environment and to communicate with other cells

10. Cell Wall

11. Nucleus Contains genetic material (DNA) Directs activities of the cell
Usually single, some cells several, RBC none
Nuclear membrane surrounds nucleus
Nuclear pores – controls the movement of molecules in and out of the nucleus
Nucleolus
found inside nucleus
makes ribosomes

12. Nucleus

13. Endoplasmic Reticulum
Transports molecules throughout the cell
Made of membranes that act as channels or passageways

14. Golgi Apparatus (also called Golgi “body” or “complex”)
Packages proteins and other molecules for transport out of the cell
Does this by surrounding the protein with membranes and puts the proteins in a “vesicle” (tiny vacuole)

15. Cisternae cis face Proteins trans face Protein Ribosome
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Cisternae
cis face
Proteins
trans face
Transport
vesicle
Golgi
apparatus
Protein
Vesicle
budding
from rough
endoplasmic
reticulum
Migrating
transport
vesicle
Fusion
of vesicle
with Golgi
apparatus
Ribosome

16. Organelles made of just a membrane
Vesicles – transport materials out of the cell or transports and stores materials inside the cell
Lysosomes - membrane-bound vesicles containing digestive enzymes
Vacuoles - contain water and other materials; used for storage
plant cells have usually 1 large vacuole
animal cells have several small vacuoles

17. Cytoplasm Extracellular fluid
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Cytoplasm
Endoplasmic
reticulum
Phagocytosis
Food
vesicle
Golgi
apparatus
Lysosomes
Transport
vesicle
Old or damaged
organelle
Plasma
membrane
Digestion of
phagocytized
food particles
or cells
Breakdown
of old
organelle
Extracellular
fluid

18. Ribosomes Make proteins
Some ribosomes float around in the cytoplasm while others are attached to the endoplasmic reticulum

19. glucose + oxygen  carbon dioxide + water + energy
Mitochondria
Releases energy from glucose (cellular respiration)
glucose + oxygen  carbon dioxide + water + energy
Structure - outer and inner membranes, (folds called cristae)
Have their own DNA

20. carbon dioxide + water  glucose + oxygen
Chloroplasts
Traps energy from the sun to make glucose in photosynthesis:
carbon dioxide + water  glucose + oxygen
Grana – closed compartments of stacked membranes
Thylakoids – disc shaped structure – light capturing pigment
Stroma – fluid matrix

21. Cytoskeleton
Network of protein fibers supporting cell shape and anchoring organelles
Actin filaments
cell movement
Microtubules
Hollow tubes
Facilitate cell movement
Centrioles – barrel shaped
organelles occur in pairs –
help assemble animal cell’s microtubules
Intermediate filaments
Stable - don’t break down
Actin
Microtubules
Intermediate
filaments

22. Cytoskeleton

23. Cytoplasm
Includes the cytosol (liquid), organelles and dissolved sugars, etc. within the cell membrane
Every chemical reaction takes place within the cytoplasm