1. Cell Discovery, Theory, & Organelles
Direct Instruction
Synthesize Notes on 26R

2. Cell Diversity and Size

3. First Sightings of Cells
Around 1590, the invention of the microscope made it possible for people to discover and learn about objects on the micro (µ) scale. Micro = 10-6

4. One of the first people to observe cells was Robert Hooke
One of the first people to observe cells was Robert Hooke. He looked at cork samples and named what he saw “cells”.

5. Robert Hook’s composite microscope

6. Anton von Leeuwenhoek was the first person to observe what are now called bacteria. 
Matthias Schleiden found that all plants are made of cells.

7. Theodor Schwann, found that all animals are made up of cells.
Rudolf Virchow proposed that new cells are formed only from existing cells

9. The Cell Theory One of the fundamental ideas of modern biology
Includes 3 principles:
1. All living organisms are composed of one or more cells
2. Cells are the basic unit of structure and organization of all living organisms
3. Cells arise only from previously existing cells

10. Remember 2 major cell types
Prokaryotes
Eukaryotes

12. Prokaryotic cells
Cells that do not contain a nucleus & membrane bound organelles
Prokaryotes contain DNA, but only a single, circular molecule
Which kingdoms contain living organisms with only prokaryotic cells?

13. PROKARYOTES UNICELLULAR ORGANISMS EXAMPLE= cyanobacteria
Fossil 2 billion years old (left) and living (right). Note the similarities in appearance. Interspersed among the cyanobacteria colonies are chains of rod-shaped bacteria.

14. Eukaryotic cells Contain a nucleus and membrane-bound organelles
More advanced – organelles allow specialized cell functions to take place in different parts of the cell at the same time
Which kingdoms contain eukaryotic cells?

15. INTERNAL ORGANIZATION
ORGANELLES:
CELL COMPONENT THAT PERFORMS SPECIFIC FUNCTIONS FOR THE CELL

16. Parts of the cell that both eukaryotes and prokaryotes have

17. Most cells have a: Cell Wall
Thick, rigid, mesh of fibers that surrounds the outside of the plasma membrane, protecting the cell and giving it support
Which Kingdom does NOT have a cell wall??
Make sure you know what each kingdom’s cell wall is composed of!!

18. All cells have a: Plasma membrane
Plasma membrane – flexible boundary that controls the movement of substances into and out of the cell

19. Plasma Membrane The plasma membrane has selective permeability:
Allows some substances to pass through while keeping others out

20. Structure of the plasma membrane
The plasma membrane can have this selective permeability because it is composed of a phospholipid bilayer
Phospholipid bilayer = two layers of phospholipid molecules arranged with polar heads facing outside and nonpolar tails facing inside

21. Plasma membrane – phospholipid bilayer

22. Plasma membrane continued…
Proteins are embedded in the phospholipid bilayer
Held in place by polar (charged)/non-polar attractions
Help cells recognize each other
Recognize & bind specific substances
Move substances in and out of cell

23. The phospholipids create a “sea” in which other molecules can float, like apples floating in a barrel of water.

25. All Cells Have CYTOPLASM: CELL GOO INSIDE CELL
WHERE THE ORGANELLES ARE LOCATED
ALSO CALLED CYTOSOL

26. Cytoplasm
Cytoplasm=
semifluid material inside the cell’s plasma membrane
In prokaryotes, all of the cell’s functions take place directly in the cytoplasm
In eukaryotes, all of the cell’s functions take place within organelles in their cytoplasm
Cytoplasm

27. Cytoskeleton
Supporting network of long, thin protein fibers that form a framework for the cell and provide an anchor for the organelles inside the cells

28. CYTOSKELETON NETWORK OF LONG PROTEIN STRANDS IN THE CYTOSOL
NO MEMBRANE
AIDS IN MOVEMENT OF ORGANELLES
MICROFILAMENTS:
THREADS OF A PROTEIN CALLED ACTIN.
SMALLEST STRAND MAKES UP CYTOSKELETON

29. ASSIST IN MOVEMENT OF CHROMOSOME DURING CELL DIVISION
MICROTUBLES:
LARGEST STRANDS
HOLLOW TUBES
WHEN CELL IS ABOUT TO DIVIDE BUNDLES COME TOGETHER AND EXTEND ACROSS THE CELL
SPINDLE FIBERS:
THICK BUNDLES
ASSIST IN MOVEMENT OF CHROMOSOME DURING CELL DIVISION

31. All cells have: RIBOSOMES
MAKES PROTEINS
MOST NUMEROUS ORGANELLE IN THE CELL
NO MEMBRANE
60% RNA AND 40% PROTEINS MAKE UP RIBOSOME'S

32. PRODUCED & ASSEMBLED IN THE NUCLEOLUS
Many Proteins are produced by a specialized cell, e.g. antibodies
transported and used elsewhere in the organism
WHEN RIBOSOMES ARE ATTACHED TO ER:
PROTEINS INSERTED TO MEMBRANES
PROTEINS EXPORTED FROM CELL
                                       
    
   
    
Electron Micrograph of ribosomes. The ribosomes operate in chains when translating a mRNA.

33. Proteins (AA chains) being made by ribosomes from mRNA
                                                                                                                   
              
Proteins (AA chains) being made by ribosomes from mRNA
Once amino acids bond together to form a chain, it is now a protein, and can be used by the body.
Simplified translation on the ribosome

34. Translation = the language of nucleic acids translated to the language of proteins
PROTEIN CHAIN
JHK
JHK
JHK
JHK
JHK
JHK
JHK
JHK
JHK
JHK
JHK
JHK
JHK
RIBOSOMES Allow PROTEIN CHAINS to be made correctly

35. Eukaryotes have organelles that prokaryotes do not have.

36. NUCLEUS: LARGE NEAR CENTER OF CELL CONTAINS MOST OF CELLS GENETIC INFO
DIRECTS MOST ACTIVITIES OF CELL

37. Nucleus
In eukaryotic cells, the central membrane-bound organelle that manages cellular functions and contains DNA
Surrounded by a nuclear envelope – a double membrane that has nuclear pores to allow substances in and out of the nucleus

38. NUCLEAR MATRIX= PROTEIN SKELETON
NUCLEAR ENVELOPE= DOUBLE MEMBRANE AROUND NUCLEUS
CHROMOSOME= DENSELY PACKED (“X”) CHROMATIN
CHROMATIN= COMBO OF DNA & PROTEIN (stretched out chromosome)
NUCLEAR PORE= SMALL HOLES (Doors)
NUCLEOLUS= RIBOSOME SYNTHESIS, PRODUCTION

39. nucleus
nuclear
pores

40. ENDOPLASMIC RETICULUM (ER)
A SYSTEM OF MEMBRANE BOUND SACS AND TUBULES
INTRACELLULAR “HIGHWAY”
MOLECULES MOVE FROM ONE PART OF CELL TO ANOTHER
2 TYPES OF ER:
SMOOTH ER= (no ribosomes)
ROUGH ER= (COVERED W/RIBOSOMES)

41. Endoplasmic reticulum
Highly folded membrane system in eukaryotic cells that is the site for protein and lipid synthesis

42. ROUGH ER:
MAKE PROTEINS
USED FOR EXPORT OUT OF THE CELL
ALSO TO BE INSERTED INTO THE CELL MEMBRANE
SMOOTH ER:
INVOLVED IN PRODUCTION (SYNTHESIS) OF STEROID GLAND CELLS
REGULATION OF CALCIUM LEVELS
BREAKDOWN OF TOXIC SUBSTANCES BY LIVER CELLS

43. ROUGH ER
SMOOTH ER

44. Golgi apparatus “UPS crew”
Flattened stacks or sacs of membranes that modifies, sorts, and packages proteins into sacs called vesicles
Vesicles can fuse with the cell’s plasma membrane to release proteins to the environment outside of the cell

45. GOLGI APPARATUS PROCESSING PACKAGING SECRETING ORGANELLE
SYSTEM OF MEMBRANES “PANCAKES”
MODIFIES PROTEINS FOR EXPORT BY CELL

47. Vacuoles “storage crew”
Membrane-bound vesicle for temporary storage of materials such as food, enzymes, and wastes

48. LYSOSOME “clean up crew”
SMALL
SPHERICAL ORGANELLE
ENCLOSE ENZYMES in a SINGLE MEMBRANES
DIGEST PROTEIN, CARBS., LIPIDS, DNA, RNA
When needed: OLD ORGANELLES, VIRUSES, BACTERIA THAT WERE INGESTED
RARE IN PLANT CELLS

49. MITOCHONDRIA CONTAIN THEIR OWN DNA (circular)
SURROUNDED BY A DOUBLE MEMBRANE

50. Mitochondria “Power-house” “Mighty Mouse”
Converts fuel (sugars) into the energy molecule ATP for the rest of the cell

51. MITOCHONDRIA IN HUMAN LIVER CELL
TRANSFER ENERGY FROM ORGANIC COMPOUNDS (pyruvate) TO ATP VIA CHEMICAL RXN’S
ATP = (AdenosineTriPhosphate) MOLECULE THAT MOST CELLS USE AS ENERGY CURRENCY
CAR (MITOCHONDRIA)
GASOLINE (CHEMICAL RXN)
GAS + ENGINE = CAR STARTS (ATP MADE)
CAR RUNS (ENERGY)
MITOCHONDRIA IN HUMAN LIVER CELL

52. SURROUNDED BY: 2 MEMBRANES CRISTAE: OUTER & INNER
THE LONG FOLDS OF THE INNER MEMBRANE
ENLARGE SURFACE AREA
WHERE CHEMICAL RXNS TAKE PLACE

53. HOW CELLS MOVE
CELLS USE HAIRLIKE STRUCTURES THAT EXTEND FROM THE SURFACE OF THE CELL
SHORT & IN LARGE QUANTITIES = CILIA
LONG & LESS NUMEROUS = FLAGELLA

54. Cilia and Flagella Flagella Cilia
Long, tail-like projection with a whiplike motion that helps a cell move through a watery environment
Cilia
Short, numerous projections that look like hair and function in cell movement

55. Plant cells have 3 structures that animal cell lack
1. Cell wall
2. Chloroplasts
3. Central vacuole

56. Chloroplast
Double membrane organelle that captures light energy and converts it to chemical energy through photosynthesis

57. Central vacuole
Membrane bound space that stores water; Aids in the rigidity of the cell

58. Draw/Color Animal Cell
Draw/Color Plant Cell
Draw/Color Animal Cell