CELLS: THE BASIC UNIT OF LIFE

1. CELLS: THE BASIC UNIT OF LIFE

2. Some Cell Fun Facts • You can grow heart cells in a petri dish. • Humans have an estimated 10 trillion cells. • The largest known cell is an unfertilized ostrich egg cell. • The word cell comes from the Latin word cellula, meaning, “small room”. • One single cell contains two meters of DNA. • Humans shed and re-grow outer skin cells about every 27 days.

3. Cells Discovered in 1665 Why didn’t we know about cells before this?

4. Robert Hooke’s microscope:

5. Section One: The Diversity of Cells Part 1:The Discovery of Cells 1665

6. Robert Hooke • First person to describe cells • Also looked at feathers, fish scales, and eyeballs of house flies • Mostly looked at plants and fungi (these things have cell walls)- makes them easy to see

8. 1673 ANTON van LEEUWENHOEK Found cells in other organisms…. • SAW “ANIMALCULES” IN POND SCUM • ALSO SAW BLOOD CELLS AND BACTERIA for the first time

9. 200 Years Later…

11. 1838 • Matthias Schleiden, a German scientist said….all plant parts are made of cells • One year later, Theodor Schwann, a German scientist that studied animals stated that all animal tissues are made of cells

12. 1858 Rudolf Virschow • Said that all cells form only from other cells

13. THE CELL THEORY: • 1. ALL ORGANISMS ARE ONE OR MORE CELLS • 2. CELL IS THE UNIT OF ALL LIFE • 3. All cells come from existing cells

14. 1. Cell membrane-outer covering 2. Organelles-small bodies in the cytoplasm 3. DNA(genetic material) 4. Cytoplasm- the fluid inside a cell along with all the cell’s contents Small size Smallest=bacteria Largest=ostrich egg how big animation 4 Parts found in all Cells All cells have a …

16. Two Kinds of Cells: • 1. Cells without a nucleus • Called Prokaryotic cells • These can be either: • bacteria or archaea • Are super small in size • 2. Cells with a nucleus • Called Eukaryotes- • (these are the cells in plants, animals and fungi)

17. PROKARYOTIC CELLS • Bacteria, and Archaea • NO NUCLEUS • NO MEMBRANES AROUND ORGANELLES • CIRCULAR DNA (looks a little like a rubber band)

18. Bacteria • Most common prokaryotes • Smallest cells known • Live almost everywhere • No nucleus but DO have DNA • DNA is long and shaped like a twisted rubber band (circular shaped) • No membrane-covered organelles • Do have ribosomes and cell wall

19. Brainpop

20. Archaea… • Same as bacteria except: • Ribosomes are different…..are more like Eukaryotic ribosomes • Cell wall and cell membranes are made of different materials • Many live in Bizarre environments! • Ex. heat-loving, salt-loving, methane-making archaea

22. SURFACE TO VOLUME RATIO: • ORGANISMS NEED SMALL CELLS TO KEEP THE RIGHT SURFACE TO VOLUME RATIO • IF A CELL GROWS TOO BIG, THERE WON’T BE ENOUGH OPENINGS IN THE SURFACE TO LET MATERIALS IN AND OUT !

25. EUKARYOTIC CELLS(our cells) • (ALL CELLS)EXCEPT bacteria and Archaea • Are 10 times bigger than bacteria • Have a NUCLEUS • Have MEMBRANE –COVERED ORGANELLES • Have LINEAR DNA found inside a nucleus

26. Really important cell vocab: • CELLULOSE- tough stuff in plant cell walls • ATP- the “energy molecule” for a cell, (is like gasoline for a car) • DNA- instructions for the cell • PHOSPHOLIPIDS- the stuff all membranes are made of

27. Section 2The Inside of a Eukaryotic Cell The “true” cell. plants animals fungi

28. Fluency Chart…

29. Plant Cells Video:

30. CELL WALL • IN PLANT CELLS (and algae) ONLY • Made of a hard material called Cellulose • Provides strength and support to the cell membrane • When you look at dried hay, sticks and wooden boards you are seeing the cell walls of dead plant cells!

31. PLANT CELL WALL PICTURES:

32. CELL MEMBRANE • All cells are covered by this • Is formed by phospholipid molecules • Allows nutrients in • Allows waste products out:

34. Cytoskeleton A web of proteins in the cytoplasm that acts as a muscle and a skeleton. It helps a cell retain its shape and moves organelles around.

35. NUCLEUS: • Library, or Town center • Stores the DNA • Has all the “secret info” for the organism

36. RIBOSOMES: • SMALLEST of all ORGANELLES (THE DOTS) ON THE E.R. • (only organelle without a membrane) • Act like factories for making proteins

37. MITOCHONDRIA: • Power plants…release energy for the cell • Make the ATP Used in all cell ( activities)

38. VACUOLE: • Is really big in plant cells • Small in animal cells • Serves as a water storage compartment

39. CHLOROPLASTS:(plant cells only!) • Contains chlorophyll • Captures sunlight to make food (sugar) used by mitochondria • Makes plants appear green

40. GOLGI COMPLEX: • FedEx Delivery • Gets rid of things inside the cell • Shipping and Handling

41. Cellular Digestion… LYSOSOMES: "suicide sacs" • Contain digestive enzymes • Clean-up/ destroy cell waste, sometimes called the recycling center • Can act as security to protect the cell from invaders • Sanitation company? Mainly in animal cells

42. ENDOPLASMIC RETICULUM (ER) • Post office, delivery system, tunnel system • Makes lipids for membranes, processes and transports proteins CELL: ER

43. Cytoplasm

44. VESICLES: Membrane –covered compartments inside the cell

45. Animal cells: human cheek cells

46. Another Fun Fact... • Scientists believe that mitochondria and chloroplasts originated as a prokaryotic cell that was “eaten” by larger cells. They ended up surviving inside. • EVIDENCE? • Both have two membranes • Have a) ribosomes and b) circular DNA • Same size as bacteria • Divide like bacteria

47. Sec.3: The Organization of Living Things… (Small to big) • CELLS • TISSUES • ORGANS • ORGAN SYSTEMS • ORGANISM

48. Organism • Anything that can perform life processes by itself • Organisms can be: • Unicellular-(single celled) • Multicellular- (consists of many cells) Euglena:

49. Oh the Joy of being multicellular ! • Larger size • Longer life • Specialization • Each type of cell has a special job • Makes the organism more efficient

50. Structure and Function • In an organism, structure and function are related. • Example: Alveoli air sacs in the lungs: • See fig. 4 p.79