1. Cell Structure & Function

2. Cell Theory All living things are made up of cells.
A cell is the smallest unit that is capable of performing life functions.
All cells come from preexisting cells through cell division.
(1839)Theodor Schwann & Matthias Schleiden
“ all living things are made of cells”
(1858) Rudolf Virchow
“all cells come from cells”

3. Principles of Cell Theory
All living things are made of cells
Smallest living unit of structure and function of all organisms is the cell
All cells arise from preexisting cells
(this principle discarded the idea of spontaneous generation)

4. Cell Exploration Light Microscopes High resolution video technology
Living organisms can be seen
Light limits the resolution so extremely small things like proteins
and viruses cannot be observed
High resolution video technology
Allows scientists to see time
elapsed movies of cells as the
grow, divide and develop.

5. Transmission Electron Microscopes (TEMs)
Can see more detain and extremely small structures
Beams of electrons must pass through ultra-thin sliced samples therefore no living things can be seen.

6. Scanning Electron Microscope (SEMs)
Beams of electrons scanned over the surface of a specimen produces a 3D image
Samples must be chemically preserved and removed of all water so no living things can be seen.

7. Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell
Nerve Cell

8. Cell Size

9. Characteristics of All Cells
A surrounding membrane
Protoplasm – cell contents in thick fluid
Organelles – structures for cell function
Control center with DNA

10. Two Types of Cells

11. Prokaryotic First cell type on earth
Do not have structures surrounded by membranes
Few internal structures
One-celled organisms,
Bacteria .

12. Eukaryotic Contain organelles surrounded by membranes
Most living organisms.
Include fungi, protists, plant, and animal cells
Possess many organelles

13. Representative
Animal Cell

14. Representative
Plant Cell

15. Cell Organelles Organelle= “little organ”
Found only inside eukaryotic cells
All the stuff in between the organelles is cytosol
Everything in a cell except the nucleus is cytoplasm

16. Inside the Cell- Nucleus Directs cell activities
Separated from cytoplasm by nuclear membrane
Contains genetic material - DNA
Usually the easiest organelle to see under a microscope

17. Nucleolus
Dense area inside the nucleus
Contains RNA to build proteins

18. Nuclear Membrane
Also called as perinuclear envelope, it surround nucleus
Made up of lipid bilayer, has two cellular membranes, separated by a space
Openings allow material to enter and leave nucleus

19. Structure

20. Chromosomes In nucleus Made up of DNA
Contain instructions for traits & characteristics

21. Cytoplasm Gel-like mixture Surrounded by cell membrane
Contains hereditary material

22. Endoplasmic Reticulum
Moves materials around in cell
Connected to nuclear membrane
Highway of the cell
Rough ER: studded with ribosomes; it makes proteins
Smooth ER: no ribosomes; it makes lipids

23. Ribosomes Each cell contains thousands Site of protein synthesis
Found attached to rough ER or floating free in cytosol
Produced in a part of the nucleus called the nucleolus

24. Mitochondria
Produces energy through chemical reactions – breaking down fats & carbohydrates, hence called “Powerhouse of the cell”
Controls level of water and other materials in cell
Recycles and decomposes proteins, fats, and carbohydrates
Bound by a double membrane
Has its own strand of DNA

25. Cell Wall Found in plant and bacterial cells Rigid, protective barrier
Located outside of the cell membrane
Made of cellulose (fiber)

26. Golgi Apparatus Looks like a stack of plates
Stores, modifies and packages proteins
Molecules transported to and from the Golgi by means of vesicles

27. Lysosomes Garbage disposal of the cell
Contain digestive enzymes that break down wastes
Transports undigested material to cell membrane for removal

28. Chloroplast Found only in plant cells
Contains the green pigment chlorophyll
Site of food (glucose) production
Bound by a double membrane

29. Vacuoles
Large central vacuole usually in plant cells, Help to maintain shape
Many smaller vacuoles in animal cells
Storage container for water, food, enzymes, wastes, pigments, etc.

30. Cell Division
Mitosis & Meiosis

31. Why Do Cells Divide?
The larger a cell becomes, the more demands the cell places on it's DNA.
It also has more trouble moving enough food and wastes across its cell membrane.

32. Takes place in Regular Body Cells
Cell Division
Also known as Mitosis
Takes place in Regular Body Cells
Keeps Cells Living and Growing

34. The Basic Phases of a Cell’s Life:
Mitosis
The Basic Phases of a Cell’s Life:
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

35. Interphase – The Cell spends the majority of its life here, growing and functioning. During the S Phase of the Cell Cycle, the DNA replicates, in anticipation of Mitosis

36. In Early Prophase of Mitosis the Chromosomes get small, centrioles move to the poles of the nucleus, and spindle fibers develop
Pair of Centrioles
Chromosomes consisting of 2 Sister Chromatids
Spindle Fibers

37. Late Prophase happens when the Nuclear Envelope disintegrates and spindle fibers begin to move Chromosomes toward the center of cell.
Spindle Fibers
Chromosomes

38. During Metaphase the Chromosomes line up across center of the cell, also called the equator, or Metaphase plate.
Spindle Fibers
Equator, or Metaphase Plate
Chromosomes

39. In Anaphase the Chromatids that make up each Chromosome move apart and travel to opposite ends of cellular spindle
Daughter Chromosomes
Chromatid
Chromosome

40. In Telophase an envelope surrounds each set of Chromatids to form new Nucleus and the Cytoplasm starts to divide
Cleavage Furrow

41. Cytokinesis takes place when the Cytoplasm divides and two cells with identical genetic material are formed
Daughter Cells

42. Interphase
Prophase
Metaphase
Anaphase
Telophase

43. Original Gamete Metaphase Anaphase Telophase Cytokinesis
2 Daughter Cells Metaphase 2 Anaphase 2 Telophase 2 Cytokinesis – 4 Gametes