1. The Cell
Chapter 4

2. Cells Marks the boundary between the “living and the dead”
Structural and functional unit of an organism
Smallest structure capable of performing all of the functions necessary for life

3. What is a cell? Why do we care? We have TRILLIONS of them!! (@65)
Every organism is composed of one or more cells
Basic unit of structure and
function in organisms
All come from pre-existing cells
Cell Theory

4. All cells……. Have an outer plasma membrane Contain DNA
Enclosed within the cell somewhere
Contain cytoplasm

5. Plasma Membrane and Cytoplasm
All cells surrounded by a plasma membrane
Phospholipid bilayer
material inside a cell is the cytoplasm
Everything between the plasma membrane and the region of DNA
Gives cells their shape
Assist in movement of cell and organelles

6. Microscopes Compound light microscope
Multiple lenses increase magnifying power

7. Two basic kinds of cells
Prokaryotic
Nothing separates the DNA from internal cell parts
Eukaryotic
Contain organelle sacs
Nucleus – contains the DNA

9. Eukaryotic Cells

10. Examples of Eukaryotic Cells:
Animal
Plant
Fungi
Protozoa

11. Cell Walls Plant cells Permeable Protective
In addition to a plasma membrane

12. Organelles Organelles act as their own separate “organs”
They physically isolate chemical reactions inside cells
Animals and plants will differ in their organelles

15. Nucleus Encloses the DNA of a eukaryotic cell Contains chromosomes
Functions:
Prevents DNA from getting entangled with structures in the cytoplasm
Outer membranes act as a boundary

16. Components of the nucleus
Nuclear pores
Nuclear envelope
Nucleolus
Nucleoplasm
DNA
Chromosomes
Chromatin

17. Nuclear envelope
Double-membrane system composed of lipid bilayer (with pores)
Bilayers surround the fluid part of nucleus (nucleoplasm)
Continuous with the endoplasmic reticulum

18. Nucleolus
Dense mass located within the nucleus
Produces ribosomes

19. Ribosomes Site of protein synthesis
Occurs in the cytoplasm
Attached to the endoplasmic reticulum
Differ between prokaryotes and eukaryotes
Why is this important from a health aspect?

20. Endomembrane System Helps modify proteins into final form
Lipids are assembled
Compartmentalizes the cell
Main components:
1. Nuclear envelope
2. Endoplasmic reticulum (ER)
3. Golgi body
4. Various vesicles (transport)

21. 1. Nuclear envelope Merges with the membrane of the ER
Consists of membranous channels and saccules

22. 2. Endoplasmic Reticulum
Channel that snakes through the cytoplasm
Lipids assembled and polypeptide chains modified into final proteins
Can be rough or smooth
Dependant on the attachments of ribosomes
Rough ER
Processing and modification of proteins
Smooth ER
Synthesizes phospholipids

23. 3. Golgi Body (Apparatus)
Series of flattened sacs
Collects, sorts, packages, and distributes materials such as proteins and lipids
Contain enzymes that put the finishing touches on proteins and lipids

24. 4. Vesicles
Enzymes from golgi apparatus sort and package the molecules into vesicles
Tiny sac that moves through cytoplasm
Function in transport, storage, or digestion of substances
Two main types:
Lysosomes
Peroxisomes

25. Lysosome A lysosome is a membrane-enclosed sac
contains digestive enzymes to break down:
Macromolecules
damaged organelles

26. Put it all together……

27. Energy-Related Organelles
organelles specialize in converting energy to a form that can be used by the cell
Requires solar energy
Dissipates as heat
Chloroplasts
Use solar energy to synthesize carbohydrates
Carbohydrates then broken down in the…..
Mitochondria
Produce ATP molecules

28. Energy-Related Organelles
Photosynthesis
Cellular Respiration
The chemical energy of carbohydrates is converted at ATP

29. Cytoskeleton: Cilia and Flagella - Movement
Hairlike projections
Help in the movement of cells
Some examples….
Why would we need them?

31. Vacuoles Membranous sacs contractile vacuoles of protists
central vacuoles of plants

32. Prokaryotes
Archae
Bacteria

33. Prokaryotic Cells Cell Wall Capsule Flagellum Plasma membrane Nucleoid
Plasmids
Ribosomes