1. Bellringer What is a cell?
Recall your work yesterday. When classifying cells, what are the two groups scientists separate cells into?

2. USING A MICROSCOPE
Light Microscopes and Total Power Magnification

3. Uses We can use microscopes to observe cells in greater detail
Light microscopes are what we will use in class
More complicated microscopes, like scanning and electron transmission microscopes, allow us to see prokaryotic and eukaryotic cell differences in greater detail

4. Parts of a Light Microscope

5. Microscope: Total Power Magnification
To find this, multiply the power of the objective lens (4X, 10X, 40X), by the power of the eyepiece (usually 10X)
Example: A student is viewing a slide using an objective lens with a power of 4X. What is the total power magnification?
4 x 10 = 40X

6. CELLS
Structure and Function of Living Organisms

7. What is a Cell?
A cell is the basic structural, functional, and biological unit of all living organisms
“The building block of life”
You are made up of about 37 trillion cells!!!

8. Cell Theory
What do we know about cells?

9. Robert Hooke
In 1665, Robert Hooke used an early microscope to look at a thin slice of cork, a plant material.
Cork looked like thousands of tiny, empty chambers.
Hooke called these chambers “cells.”

10. Hooke’s Original Sketches

11. History
In 1838, Matthias Schleiden concluded that all plants were made of cells.
In 1839, Theodor Schwann stated that all animals were made of cells.
In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells.
These discoveries led to the cell theory.

12. 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 from existing cells.

13. Types of Cells Prokaryotic Eukaryotic Simple Cells Complex Cells
Plant and Animal Cells

14. Prokaryotic Cells
Prokaryotic cells are less complex than eukaryotic cells
No membrane bound organelles; smaller
Single-celled organisms (ex. Bacteria)

15. Eukaryotic Cells
Eukaryotic cells are complex cells made up of membrane bound organelles
Each organelle within the cell carries out different roles
Eukaryotic cells make up complex organisms (mostly multicellular)…like insects, fish, and mammals like you!

16. Prokaryotic vs. Eukaryotic
No membrane bound organelles (no mitochondria, nucleus, vacuole, or chloroplasts)
Ribosomes
DNA and RNA (not enclosed)
Circular DNA called plasmids
Smaller size
Contains membrane bound organelles
Ribosomes
DNA and RNA (enclosed by membrane)
DNA double-helix strands
Larger size

17. Eukaryotic Cells
Animal vs. Plant

18. Animal Cell Nucleus Plasma Membrane Mitochondria Vacuoles Ribosome
Cytoplasm
Lysosome

19. Plant Cell Nucleus Plasma Membrane Mitochondria Ribosome Cytoplasm
Vacuole (large)
Chloroplasts
Cell Wall

20. What differences do you see right away?

21. Nucleus The “control center” Holds the DNA
Dark spot inside nucleus is called the nucleolus (it helps makes the ribosomes)
Nucleus

22. Mitochondria The “powerhouse” of the cell
It produces most of the energy for the cell
Breaks down food to make ATP
ATP is major fuel for all cell activities that require energy
Folded inner membrane increase the surface area for energy production during respiration

23. Plasma Membrane The “gate” of the cell
Double membrane structure controls what comes in and out of the cell
“YOU SHALL NOT PASS”
Plasma Membrane

24. Ribosome Protein producer The ribosome makes proteins for the cell

25. Vacuole “Storage tanks” of the cell
It stores food, water, and chemicals in the cell
Plant cell vacuole is much larger; controls Turgor Pressure-keeps plant upright (no water=wilting)
Vacuole

26. Vacuole in Plants

27. Cytoplasm
Jelly/gel
A liquid/gel like substance that surrounds the organelles
Cytoplasm

28. Lysosome (Animal Only)
The “garbage cans”
Break down and digest waste products using enzymes
Lysosome

29. Cell Wall (Plant Only) “Supporter/protector”
The cell wall shapes and protects the plant cell
Cell Wall

30. Chloroplasts (Plant Only)
Food producers
They are green
Contain green chlorophyll and trap energy from the sun for photosynthesis
Chloroplast

31. Organelle Interactions
All these organelles work together to keep the cell running!!
What do you think would happen if…
The Mitochondria or chloroplasts stopped working?
The Plasma Membrane didn’t do it’s job?
The Nucleus stopped directing activities?

32. Specialization of Cells
Cells all begin as undifferentiated-DNA and genetics play a role in determining the type of cell (ex. nerve cell, muscle, blood…)
We will talk more about this later!

33. Where would you need more…
Mitochondria?
Chloroplasts?
Cell organelles can be more concentrated based on needs!

34. Question of the Day
Which cellular process is most closely related the presence of chloroplasts in eukaryotes?
Metabolism
Photosynthesis
Aerobic respiration
Lactic acid fermentation

35. UNICELLULAR ORGANISMS
Structure and Adaptations

36. Unicellular Organisms
A “multicellular” organism is composed of many cells (ex. You are composed of many animal cells; plants are composed of many plant cells)
“Unicellular” means they are composed of a single cell!
Ex. Bacteria, protozoa, euglena

37. Structures of Unicellular Organisms
Unicellular organisms have many structures that help them survive
Contractile vacuoles
Cilia
Flagella
Psuedopods
Eyespots

38. Contractile Vacuoles
Stores excess water that enters the cell, and expels it to the exterior
It expands when filling with water, then contracts, expelling the contents back out
Found in: protists + unicellular algae

39. Eyespots
A dark area that functions in light reception; influences motion so that the organism can move toward/ away from light
Toward (positive phototaxis)
Away (negative phototaxis)
Found in: green algae; photosynthetic unicellular organisms

40. Movement Cilia Flagella Many hair like structures
Cilia
Many hair like structures
Often used for movement
Non-motile cilia serve as sensory organelles
Flagella
Single, whip like tail used for movement
Found in: bacteria, protists, specialized plant, animal and fungi cells

41. Movement
Psuedopods
“False feet” that help the unicellular organism move about
Sometimes used to obtain food (phagocytosis)

42. Adaptive Behaviors
Recall that “taxis” is an innate behavior in response to an outside stimuli

43. Chemotaxis Movement in response to chemicals (“chemo”).
Some single celled organisms direct their movement according to chemicals in their environment
Found in bacteria and single-cell or multicellular organisms
Find food (e.g., glucose)
Flee from poisons (e.g., phenol)
Critical to early development

44. Phototaxis Movement toward or away from light.
Movement toward or away from light.
Many plant-like unicellular organisms will move toward light to better photosynthesize, just like plants will tilt toward the window
Positive phototaxis: if the movement is in the direction of increasing light intensity
Negative phototaxis: if the movement is in the opposite direction of light intensity