1. A View of the Cell

2. From Molecules to Cells The Evolution of Cells
Life arose in the oceans
Molecules collide and reactions take place
Larger biomolecules form (nucleic acids, lipids …)
Membranes spontaneously form from lipid materials – provides a boundary
Cells begin to replicate; transfer genetic material

3. Why do we study cells?

4. The cell theory is made up of three main ideas:
All organisms are composed of one or more cells
The cell is the basic functional unit of organisms
Schleiden – botanist (1838) - all plants are composed of cells
Schwann – zoologist (1839) - all animals are composed of cells
All cells come from preexisting cells
Virchow – physician (1855) - all cells come from other cells

5. Activities of life
Most everything you think of a whole organism needing to do, must be done at the cellular level…
reproduction
growth & development
energy utilization
response to the environment
homeostasis

6. Relationship between structure & function
Diversity of Cells
Relationship between structure & function

7. ALL CELLS… contain cytoplasm (fluid-filled interior)
are surrounded by a plasma membrane
contain DNA (genetic material) in the form of chromosomes/chromatin
have ribosomes (organelles that make proteins)

8. Two Cell Types Prokaryotic = no true nucleus
1st to evolve
Bacterial cells
no membrane bound organelles
Smaller size
Eukaryotic – has a nucleus
contain membrane bound organelles
much larger
classified as either plant or animal cells

10. PROKARYOTIC CELL - BACTERIA ONLY
Ribosomes
DNA
Plasma Membrane
Cytoplasm

11. EUKARYOTIC CELLS - Plant & Animal Cells
Nucleus (containing DNA)
plasma membrane
ORGANELLES
(membrane bound)
Ribosomes

12. What jobs do cells have to do?
transport materials, maintain homeostasis
Take in what is needed; get rid of waste
make proteins
proteins control every cell function
make energy
for daily life; for growth
build more cells
growth
reproduction
repair

13. Maintaining Homeostasis
Homeostasis = regulation
maintenance of a stable internal environment
Requires bringing in & storage of needed materials
Transporting materials to their intended destination
Elimination of waste materials

14. What happens if an organelle (like a lysosome) doesn’t work?
don’t digest a biomolecule
instead biomolecule collects in lysosomes
lysosomes fill up with undigested material
lysosomes grow larger & larger
eventually disrupt cell & organ function
Tay-Sachs disease
lipids build up in brain cells
child dies before age 5
Tay-Sachs

15. Making Proteins: The Endomembrane system

16. endoplasmic reticulum
nucleus
protein on its way!
TO:
DNA
RNA
TO:
vesicle
TO:
vesicle
ribosome
TO:
protein
finished protein
Golgi apparatus
Making Proteins

17. Mitochondria & Chloroplasts
Making Energy
Mitochondria & Chloroplasts
BOTH:
transform energy
double membranes
contain own DNA
self-replicate
Dividing mitochondria
Dividing Bacteria

18. Endosymbiotic theory 1981 | ??
Mitochondria & chloroplasts were once free living bacteria
became engulfed by a larger eukaryote
evolutionary advantage for both
one supplies energy
the other supplies raw materials & protection
Lynn Margulis
U of M, Amherst

19. Endosymbiosis Evolution of eukaryotes PLANT CELLS mitochondria
chloroplast
Early EUKARYOTE
Engulfing photosynthetic Prokaryote
Engulfing Aerobic Prokaryote
Early PROKARYOTE
mitochondria
ANIMAL CELLS