1. Cells!

2. The Cell Theory All Living Things are composed of cells
Cells are the basic units of structure and function in living things
New cells are produced form existing cells

3. Basic Cell Structures All cells have: Some cells have: Cell membrane
Cytoplasm: within the cell membrane, but not in the nucleus
Some cells have:
Cell wall
Nucleus

4. Biologists divide cells into two categories: Eukaryotes and Prokaryotes

5. Prokaryotes Generally smaller and simpler
Have cell membranes and cytoplasm
DO NOT CONTAIN NUCLEI
All bacteria are prokaryotes
Escherichia coli: lives in your intestines
Staphylococcus aureus: can cause skin infections

9. Eukaryotes “Eu” – true “karyon” – nucleus Also have A cell membrane
Cytoplasm
Organelles

10. Cell Walls Provides support and protection for the cell
Lies outside of the cell membrane
Found in
Plants
Algae
Fungi
Nearly all prokaryotes
*ANIMALS CELL DO NOT HAVE CELL WALLS

12. Nucleus
THE NUCLEUS CONTROLS MOST CELL PROCESSES AND CONTAINS THE HEREDITARY INFORMATION OF DNA
Robert Brown – botanist
Chromatin
Chromosomes

16. Use this article to define
Use this article to define
Nucleosome
Histone
Chromatin
Chromosomes
Chromatosomes

18. Chromatin Granular material visible within the nucleus
Consists of DNA bound to protein
Spread throughout the nucleus

19. Chromosomes
When a cell divides, chromatin condenses to form chromosomes
Chromosomes: Distinct, threadlike structures containing the genetic information that is passed from one generation of cells to the next

20. Nucleolus
Most nuclei contain a small, dense region known as the nucleolus
Assembly of ribosomes begins here

21. Nuclear Envelope Double membrane layer
Contains nuclear pores – allow material to move into and out of the nucleus
Nucleus sends a steady stream of RNA and other information-carrying molecules to the rest of the cell through the nuclear pores

22. Central Dogma of Molecular Biology

24. Cytoskeleton

25. Cytoskeleton
The cytoskeleton is a network of protein filaments that helps the cell to maintain its shape
The cytoskeleton is also involved in many forms of cell movement
The cytoskeleton is made up of a number of important structures:
Microtubules
Microfilaments
(p 176)

26. Microtubules Hollow tubes of protein about 25 nanometers in diameter
Maintain cell shape and can serve as “tracks” along which organelles are moved
Important in cell division – help separate chromosomes
Form a pair of centrioles (animal cells)
Can sometimes form cilia and flagella

27. Network of Microtubules connecting cellular organelles

28. Important in cell division – help separate chromosomes
Form a pair of centrioles (animal cells)

29. Microtubules can sometimes form cilia and flagella to help the cell move through liquid

30. Microfilaments
Long, thin fibers that function in the movement and support of the cell
7 nm in diameter
Tough flexible framework - support

32. Organelles in the Cytoplasm
Ribosomes
Endoplasmic Reticulum
Golgi Apparatus
Lysosomes
Vacuoles
Chloroplasts
Mitochondria
Organelles = “tiny organs”

33. Ribosomes Making proteins Proteins are assembled ON ribosomes
Where are ribosomes assembled?
Ribosomes: small particles made of RNA and protein
Produce proteins by following coded instructions that come from the nucleus
This coded instruction is called mRNA

35. Endoplasmic Reticulum
An internal system of membranes
Only in eukaryotes
The endoplasmic reticulum is the organelle in which components of the cell membrane are assembled and some proteins are modified
Rough ER
Smooth ER

36. Rough Endoplasmic Reticulum
Involved in the synthesis of proteins
“Rough” due to the ribosomes on the surface
Newly made proteins move directly from these ribosomes into the rough er, where they are chemically modified

38. Smooth ER No ribosomes on surface It is an extension of the Rough ER
Contains many enzymes that performed specialized tasks
Ex: Synthesis of lipids

40. Rough & Smooth ER

41. Golgi Apparatus
Proteins produced by the rough endoplasmic reticulum move into a stack of membranes called the Golgi Apparatus
Enzymes in the Golgi apparatus attach carbohydrates and lipids to proteins
From the Golgi apparatus, proteins are sent to their final destination

43. Golgi Apparatus
Cis face: receiving side
Trans face: shipping side

45. Lysosomes Small organelles filled with enzymes
Breaks down lipids, carbohydrates, and proteins from food into particles that can be used by the rest of the cell
Also break down “old” organelles
Remove debris

46. Digestion
Organelle degradation

47. Vacuoles Store water, salts, proteins, and carbohydrates
Saclike structures
Found in single-celled organisms and animals
Vesicles: smaller vacuoles involved in transporting substances
Useful in plants
Pressure in these central vacuoles makes it possible for plants to support heavy structures such as leaves and flowers

49. Chloroplasts Found in plants and some other organisms
Not found in animal and fungal cells
Chloroplasts use the energy from sunlight to make energy-rich food molecules in a process known as photosynthesis
Bound by two envelope membranes and contain large stacks of photosynthetic membranes
Green pigment chlorophyll is located in the photosynthetic membranes - thylakoid

51. Mitochondria
Mitochondria use energy from food to make high-energy compounds that the cell can use to power growth, development, and movement
Found in almost all eukaryotic cells
Including plant and algae cells
Enclosed by an outer and an inner membrane
Inner membrane is folded

53. Organelles that contain their own DNA
Chloroplasts
Mitochondria
This DNA contains information that is essential for the normal function of these specific organelles

54. Mitochondrial DNA
All of a mitochondria come from the cytoplasm of the ovum, or egg cell
So, genes in the mitochondria are specifically genes from your mother

55. Endosymbiotic Theory