Systems Biology Notes (Chapter 3, Pages 87-115) Name



Biology CP ’12-13 Name________________________________

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|Cellular Biology: PART C-Cells- Structure and Function |

|All organisms are made of cells. |

|Despite the different variety of cells, their structure is remarkably similar. |

The History of Cell Theory

Consider the inorganic and organic chemicals that we have studied. Are they living?__________

Could you fill a jar with the same number of inorganic and organic molecules normally found in the human body and expect the contents of the jar to be living?_______________________________

______________________________________________________________________________

From the smallest bacterium to the largest redwood tree, all organisms are composed of:

Cells:_________________________________________________________________________

______________________________________________________________________________

The First Microscopes:

The human eye can see items as small as a pencil dot on a page (100(m). The average cell is only 20(m in diameter. How is it that we know so much about cells?

Robert Hooke: In 1665, this English scientist was building compound microscopes made of two or three lenses. He observed a thin section of cork (the outer, dead layer of a cork tree that forms the bark) and described a “great number of tiny little boxes” which he called cells. They were actually the cell walls remaining from dead cells. Hook is credited with being the first scientist to view and name cells.

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|. . . I could exceedingly plainly perceive it to be all perforated and porous. . . these pores,or|

|cells, . . . were indeed the first microscopical pores I ever saw, and perhaps, that were ever |

|seen, for I had not met with any Writer or Person, that had made any mention of them before this.|

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|Robert Hooke in Micrographia (1685) |

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Anton van Leeuwenhoek: In 1674, this Dutch lens maker built a much better lens with which he was able to observe living cells. He observed organisms in rainwater, pond water, blood and in the grime he scraped off his teeth! He called the small organisms he observed “animalcules” or little animals. Leeuvenhoek is credited with observing the first living cells.

Matthias Schleiden: In 1838, this German botanist (plant scientist) had the benefit of much more powerful lenses. He concluded that all plants are made of cells.

Theodor Schwann: In 1839, this German Zoologist (animal scientist) independently concluded that all living things are made of cells.

Rudloph Virchow: In 1858, this German scientist studied the causes of diseases. He concluded that all cells come from existing cells. This is also called the theory of Biogenesis.

The ideas of Schleiden, Schwann and Virchow form the basis for The Cell Theory.

The Cell Theory:

1.

2.

3.

| Form Leads to Function |

Cells of complex organisms display a wide diversity of structural formations. Each different structure is directly related to the functioning of the cell.

Pick any two cell types from the previous diagram – compare and contrast their specialized structure, and relate this to the cells’ function in the body.

|Prokaryotic and Eukaryotic Cells |

Cells fall into two major categories depending the complexity of their internal structures:

A. Prokaryotic Cells: _____________________________________________________________

____________________________________________________________

Examples:

B. Eukaryotic Cells: ______________________________________________________________

_____________________________________________________________

Examples (includes all cells other than bacteria):

1) ________________________ 3) ____________________________

2) ________________________ 4) ____________________________

* Differences and Similarities Between the Two Cell Types: (+ present, -- absent)

|Cell Characteristic |Prokaryotic Cell |Eukaryotic Cell |

|outer cell membrane | | |

|cytoplasm-cellular fluid | | |

|ribosomes-structures which form proteins | | |

|nucleus | | |

|chromosomes (DNA or RNA) | | |

|membrane bound organelles (little organs) | | |

|cells carry out life processes | | |

|average size of cells |1-10 (m |2-1,000(m |

|time of evolution |3.5 billion years ago |1.5 billion years ago |

|organisms exhibiting this type of cell | | |

|general shape of the cell |spherical, rod shaped, spiral |wide variety of shapes depending on |

| | |function |

|The Cell Membrane (Plasma Membrane) |

Let’s review… Fluid Mosaic Model-The cell membrane is made of 2 layers. The membrane is actually more like a fluid than a solid. Proteins “bob” like floats within the phospholipid bilayer.

Proteins may serve as transport proteins, receptor proteins, or enzymes. _________________ molecules on the outer surface serve as markers (specific to the individual organism) to help identify the cell.

* Functions of the plasma membrane:

1. Boundary between the cell __________________________________

2. Selectively permeable: ____________________________________________________

________________________________________________________________________

3. Helps cell to maintain ____________________________ so the correct amounts of solutes and solvents can be found within the cell.

|Cell Wall |

* Don’t confuse a cell wall with the cell membrane. The cell wall is located outside the cell membrane and is only present in certain organisms:

1. __________________________________________________

2. __________________________________________________

3. __________________________________________________

4. __________________________________________________

* Structure:

1. Is inflexible without breaking.

2. Is composed of multiple layers of carbohydrates and other molecules.

3. Have openings that allow small molecules in or out. Not selectively permeable.

* Function: 1) semipermeable ____________________________________________________

2) provides __________________________________________________________

Not found in animals because we need to be _________________________________________

|Nucleus |

* Structure of the Nucleus:

1. Largest structure__________________________________________________________

2. Surrounded by a double membrane that is also called the nuclear envelope.

* semi permeable: 1) Covered with small nuclear pores or openings.

2) Pores keep DNA within the nucleus but allow smaller molecules

like RNA and proteins out.

3. Contain one or more nucleoli (nucleolus is singular) which are areas composed of sections of condensed DNA and proteins (they look dark when viewed through the microscope).

* Function of the Nucleus:

1. Controls _________________________________________________________________

2. Storage center for ___________________________

3. Nucleoli function as the site for ______________________________________

Label the following eukaryotic cells:

A

B

C

D

E

AB

AC

AD

AE

BC

BD

BE

CE

Which cell – the one on the right or the left – is the Animal cell?_________ Plant cell?___________

|Cytoplasm |

* Material between the nuclear membrane and the cell membrane.

* Location: ALL CELLS (prokaryotic AND eukaryotic)

* Structure: composed of a solution that contains important solutes involved in metabolic reactions as well as organelles which function to help the cell survive. .

Examples: reactants _____________________ products ______________________________

What is the solvent of this solution? _______________________________________

* Function: 1) Area within the cell where most _______________________________ take place.

2) Holds solutes and solvents that are reactants and products of metabolic processes

ex. _____________________________________________________________

______________________________________________________________

3) Holds organelles that function as the site of the above processes: _____________

__________________________________________________________________

|Mitochondrion |

* Site of ______________________________________________

* Location: cytoplasm of all eukaryotic cells

* Structure:

* Contains its own unique DNA, proteins and ribosomes; can self-replicate.

* Contains a fluid (“matrix”) and a highly folded inner membrane (“cristae”) for the reactions of cellular respiration.

* Function of the Mitochondria:

Cellular respiration:___________________________________________________________

Which do you think would contain more mitochondria- a heart muscle cell or a skin cell?

Why? _____

_____

_____

|Chloroplast |

* Site of Photosynthesis

* Location: cytoplasm of eukaryotic autotrophs ex)

* Structure:

Contains a green colored pigment called _________________________ which captures light energy to power the reactions of ____________________.

Contains a fluid (“stroma”) and stacks (“granum”) of folded membranes (“thylakoids”) for the reactions of photosynthesis.

Photosynthesis:__________________________________________________

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* If the pigment chlorophyll causes the green color in plants, do all plant parts contain chlorophyll? ___________________________________________________________________________________

* Some prokaryotic bacteria are photosynthetic. Do they contain chloroplasts?______________________

_____________________________________________________________________________

|Vacuoles and Vesicles |

* Location: vacuoles and vesicles are both found in cytoplasm of all eukaryotic cells

* Structure: Membrane-bound, fluid filled compartment in the cell

* Functions: The primary function of vacuoles and vesicles is to STORE and TRANSPORT materials throughout the cell.

1) Plant cells typically have one large central vacuole for the storage of water, nutrients, wastes and enzymes, helps in maintaining turgor pressure

2) Animal cells may contain a varying number of smaller vacuoles/vesicles that generally function to store large molecules such as food brought in through ___________________ or molecules to be released through ________________ such as large proteins or waste particles

Food vacuoles formed during endocytosis and vacuoles formed during exocytosis contain large food or waste particles.

3) Many unicellular aquatic organisms have specialized vacuoles (“contractile vacuoles”) which function to pump out excess water from the cell’s cytoplasm. Thinking back to our unit on cell transport – why is this a necessary structure in these organisms?

|Lysosomes | | Site of Cellular Hydrolysis (Digestion)

* Location: cytoplasm of all animal cells, but rare in plant cells. Plant cells store their digestive enzymes in the large, central water vacuole.

* Structure: membrane-bound sac filled with digestive enzymes. Produced by the Golgi apparatus.

* Function: 1) The site of cellular digestion or ____________________________________

2) Compartment that maintains the correct pH for the enzymes while protecting the cell from the digestive enzymes that might break down organelles.

Ribosomes | |

* Only organelle which is found in both ________________ and __________________ cells.

* Produced by the _______________________ .

* Location:

Can be found attached to the_________________________

or floating free in __________________________________

* Structure:

One large, and one small subunit of RNA bound with proteins.

Not surrounded by a membrane but still considered an organelle.

* Function: The site of ___________________________________.

Endoplasmic Reticulum | |Structure: network of membranous tubes and sacks. It is a very dynamic organelle, constantly forming and breaking down.

* Location: Cytoplasm of all eukaryotic cells.

* Two Types of ER: 1) rough ER (RER) ____________________________________________

2) smooth ER (SER) ___________________________________________

* Functions:

Rough ER |Smooth ER | |

Ribosomes attached to the rough ER are the site of protein synthesis.

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Site of detoxification of drugs like alcohol and sedatives. Cells in people who use these drugs form large amounts of smooth ER. | |

ER membranes act as transport channels to move proteins and other solutes throughout the cell.

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Also functions in synthesis of lipids.

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Golgi Apparatus or Golgi Bodies | | |

* Structure: series of sack-like membranes that look, in drawings, like stacks of pita bread. The margins of the stacks have bubble-like secretory vesicles, which form from the main stacks of membranes. Lysosomes are formed from Golgi vesicles.

* Location: Cytoplasm (often found between Rough ER and cell membrane) of all eukaryotic cells.

* Function:

Microtubules | |

• Structure:

Hollow tubes composed of ___________________ which make up various structures in different types of cells. Can be synthesized or broken down as needed.

• Functions of different types structures composed of microtubules:

1) Cytoskeleton: In animal cells which lack cell walls and large, central vacuoles, microtubules form the cytoskeleton.

The cytoskeleton provides shape and support to the cell and a channel or track for organelles to travel on as they move about the cell.

2) Centrioles:

3) Flagella:

4) Cilia:

Summary of Cell Structure: | |Directions: Place a + in the space if the structure is present. Place a -- if it is absent.

Cell Structure

|Prokaryotic Cell

(Bacteria) |Eukaryotic Plant Cell (Elodea) |Eukaryotic Animal Cell (Cheek Epithelial) | |Cell Wall | | | | |Cell Membrane | | | | |Cytoplasm | | | | |Chromosomes

(DNA RNA) | | | | |Nucleus | | | | |Nucleolus | | | | |Mitochondria | | | | |Chloroplasts | | | | |Vacuoles or Vesicles | | | | |Lysosomes | | | | |Ribosomes | | | | |Smooth and Rough Endoplasmic Reticulum | | | | |Golgi Apparatus | | | | |Cytoskeleton | | | | |Centrioles | | | | |

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