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History of Cells.

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Presentation on theme: "History of Cells."— Presentation transcript:

1 History of Cells

2 What he saw looked like small boxes
First to View Cells In 1665, Robert Hooke used a microscope to examine a thin slice of cork (dead plant cell walls) What he saw looked like small boxes

3 Hooke is responsible for naming cells
First to View Cells Hooke is responsible for naming cells Hooke called them “CELLS” because they looked like small rooms in which monks lived

4 Anton van Leeuwenhoek In 1673, Leeuwenhoek (a Dutch microscope maker), was first to view living organisms Leeuwenhoek used a simple, handheld microscope to view pond water & scrapings from his teeth

5 Beginning of the Cell Theory
In 1838, a German botanist named Matthias Schleiden concluded that all plants were made of cells Schleiden is a cofounder of the cell theory

6 Beginning of the Cell Theory
In 1839, a German zoologist named Theodore Schwann concluded that all animals were made of cells Schwann also cofounded the cell theory

7 In 1855, a German medical doctor named Rudolph Virchow observed, under the microscope, cells dividing He reasoned that all cells come from other pre-existing cells by cell division

8 The Cell Theory All living things are made of cells
Cells are the basic units of structure and function in living things New cells are produced from living cells

9 Cells: Prokaryote vs Eukaryote

10 Cell Theory All life is made of cells.
Cells are the basic unit of life. Cells come from pre-existing cells (except for the first cell).

11 Prokaryote (no nucleus)
Concept Map Cells Prokaryote (no nucleus) Bacteria Eukaryote (nucleus) Plant Animal

12 Cells have evolved two different architectures:
Prokaryote “style” Eukaryote “style”

13 Prokaryote cells are smaller and simpler
Commonly known as bacteria microns in size Single-celled(unicellular) or Filamentous (strings of single cells)

14 These are prokaryote E. coli bacteria on the head of a steel pin.

15 Prokaryote cells are simply built (example: E. coli)
capsule: slimy outer coating cell wall: tougher middle layer cell membrane: delicate inner skin

16 Prokaryote cells are simply built (example: E. coli)
cytoplasm: inner liquid filling DNA in one big loop flagella: for swimming ribosomes: for building proteins

17 Prokaryote lifestyle unicellular: all alone colony: forms a film
filamentous: forms a chain of cells

18 Prokaryote Feeding Photosynthetic: energy from sunlight
Disease-causing: feed on living things Decomposers: feed on dead things

19 Eukaryotes are bigger and more complicated
Have chromosomes can be multicellular include animal and plant cells

20 Organelles are cell parts
Mini “organs” that have unique structures and functions

21 Cell Membranes Cell membrane
delicate lipid and protein skin around cytoplasm found in all cells

22 Nucleus a membrane-bound sac evolved to store the cell’s chromosomes (DNA) has pores: holes

23 Nucleolus inside nucleus location of ribosome factory made of RNA

24 Mitochondrion makes the cell’s energy uses Oxygen to breakdown food (glucose) to make ATP the more energy the cell needs, the more mitochondria it has

25 Ribosomes build proteins from amino acids in cytoplasm may be free- floating, or may be attached to Endoplasmic Reticulum made of RNA

26 Vesicles Sacs that are surrounded by a phospholipid bilayer Can come from the cell membrane, Golgi apparatus, or endoplasmic reticulum Helps transport materials Some are filled with enzymes to carry out digestive functions

27 Endoplasmic reticulum
may be smooth: builds lipids and carbohydrates may be rough: stores proteins made by attached ribosomes

28 Golgi Apparatus takes in sacs of raw material from ER attaches labels that determine where the protein will go sends out sacs containing finished cell products

29 Lysosomes sacs filled with digestive enzymes digest worn out cell parts digest food absorbed by cell

30 Cytoskeleton made of microtubules (proteins)
found throughout cytoplasm gives shape to cell & moves organelles around inside

31 Centrosome pair of bundled tubes called centrioles Organizes cytoskeleton, especially for cell division

32 Structures found in plant cells
Cell wall very strong made of cellulose protects cell from rupturing

33 Vacuole huge water- filled sac keeps cell pressurized stores starch

34 Chloroplasts filled with chlorophyll turn solar energy into food energy

35 How are plant and animal cells different?

36 Structure Animal cells Plant cells cell membrane Yes yes nucleus nucleolus ribosomes ER Golgi centrioles no cell wall mitochondria cholorplasts One big vacuole cytoskeleton

37 Eukaryote cells can be multicellular
The whole cell can be specialized for one job cells can work together as tissues Tissues can work together as organs

38 Advantages of each kind of cell architecture
Prokaryotes Eukaryotes simple and easy to grow can specialize fast reproduction multicellularity all the same can build large bodies

39 Examples of specialized euk. cells
liver cell: specialized to detoxify blood and store glucose as glycogen.

40 sperm cell: specialized to deliver DNA to egg cell

41 Nerve Cell Designed to send electrical signals around the body

42 Mesophyll cell specialized to capture as much light as possible inside a leaf

43 How do animal cells move?
Some can crawl with pseudopods Some can swim with a flagellum Some can swim very fast with cilia

44 Pseudopods means “fake feet” extensions of cell membrane
example: ameoba

45 Flagellum/flagella large whiplike tail
pushes or pulls cell through water can be single, or a pair

46 Cilia fine, hairlike extensions attached to cell membrane
beat in unison

47 How did organelles evolve?
many scientists theorize that eukaryotes evolved from prokaryote ancestors. in 1981, Lynn Margulis popularized the “endosymbiont theory.”

48 Endosymbiont theory: a prokaryote ancestor “eats” a smaller prokaryote
the smaller prokaryote evolves a way to avoid being digested, and lives inside its new “host” cell kind of like a pet.

49 Endo = inside Symbiont = friend

50 the small prokaryotes that can do photosynthesis evolve into chloroplasts, and “pay” their host with glucose. The smaller prokaryotes that can do aerobic respiration evolve into mitochondria, and convert the glucose into energy the cell can use. Both the host and the symbiont benefit from the relationship

51 Chlorella are tiny green cells that live inside some amoeba
Chlorella are tiny green cells that live inside some amoeba... endosymbiosis may still be evolving today!


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