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CellsIntro.notebook
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January 18, 2011
Nov 1610:26 PM
Aim: What are cells and the Cell Theory?
Do Now: List & describe as many parts of a cell as you can.
Homework: Read pp. 151 155P. 155 # 1,2,5
Define: cell membrane, cytoplasm, ribosome, prokaryote, eukaryote, nucleus, organelle, Cell Theory, Anton von Leeuwenhoek, Robert Hook, Schleiden, Schwann, Virchow, Surface area
LE1 & 3 12/10/10
Nov 2311:50 AM
Class Notes LE5
Nov 2310:12 AM
Class Notes LE 1 11/23/09
Nov 248:30 AM
Aim: What is the cell theory? What defines the shape & size of cells?
11/24/09
Do Now: What is the difference between prokaryotic and eukaryotic cells?Homework: Rd 151155P.155 # 15Quiz Wednesday Cells Parts, Theory
Nov 248:30 AM
Aim: What is the cell theory? What defines the shape & size of cells?
11/24/09
Do Now: What is the difference between prokaryotic and eukaryotic cells?
Homework: Rd 151155P.155 # 15
Nov 248:38 AM
CellsIntro.notebook
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January 18, 2011
Nov 248:42 AM Dec 1312:02 PM
LE 3 12/13/2010
Nov 1610:38 PM
Cell Discovery & Cell Theory
Robert Hook (1665): Under crude microscope looks at slices of cork magnified 30x observed little boxes, called them "Cells"
Cell Theory (1838 1839)• Schleiden, Botanist (German): observes that all plants made of cells
• Schwann, Zoologist (German): discovers that all animals appear to be made of cells
• Virchow, Physician (German): determinethat cells come only from existing cells
Cell Theory states:1. All living things are made up of one or more cells2. Cells are the basic unit of structure & function in oganisms3. All cells come from previously existing cells
LE 1 &3 12/10/10
Nov 248:40 AM
LE3 12/10/10
Nov 248:39 AM Nov 248:40 AM
CellsIntro.notebook
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January 18, 2011
Nov 248:40 AM Dec 1312:52 PM
Aim: What are the characteristics of cells?
Do Now: What are the 3 parts of the cell theory?
Homework:Rd pp.156158P.158 # 2,3Quiz on cells Wednesday
Dec 147:55 AM Dec 1411:08 PM
Aim: What are the structures and functions of cell organelles?
Do Now: Quiz on Cell Intro
Homework
Dec 1411:10 PM
1. Cell's shape reflects its function
2. At least 200 types of cells in human body
Cell Characteristics
Dec 1411:09 PM
Cell membraneAll cells are surrounded by a cell membrane.Functions:• separates the contents of the cell from its environment • regulates the passage of molecules into and out of the cellStructure• contains proteins that have a variety of functions• some proteins are receptors which can detect the presence of certain kinds of molecules in the surrounding fluid
Surface Area to Volume Ratio• Cell needs a large surface area.• Cells are limited in size because larger cells have a smaller surface to volume ratio• Cells that are specialized for absorption (ex: intestinal cells) have folds • in the plasma membrane called microvilli that increase the surface area.• Pseudopodia are temporary extensions of the plasma membrane used for movement or to engulf particles (Amoeba)
CellsIntro.notebook
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January 18, 2011
Nov 1610:48 PM
Why don't cells just keep growing into giant blobs?Why is every cell microscopic?
Cell size is limited by a cell's surface area to volume ratio• as a cell gets larger, it uses more nutrients & makes more wastes• the longer it will take for these substances to travel in a larger cell• A cell's ability to exchange material is estimated by calculating the Surface Area to Volume Ratio (SA: V)
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Cells with a greater Surface Area to Volume Ratio can exchange substances more efficiently
Cells with the same shape compared show this!
1. Calculate the surface area of each cell. (SA= area x 6)2. Calculate volume (L x W x H)3. Determine the distance from the center of cell to the cell membrane.4. Show the ratio of SA: V
Grandma's bedroom empty
Nov 239:10 AM
Comparing Surface Area: Volume ratios of cells
Nov 239:25 AM
Dec 1411:14 PM
Cell WallThe cell wall functions to support and protect the cell.• Plants have cell walls composed of cellulose • Fungi have walls composed of chitin • The cell walls of these onion skin cells can be easily seen:
Dec 1411:15 PM
Nucleus :The nuclei can be seen in the photograph of human cheek cells
• Nucleus contains DNA• DNA contains instructions needed to produce proteins that control metabolism and other cell functions
CellsIntro.notebook
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January 18, 2011
Dec 1411:19 PM
CytoplasmCytoplasm is the material enclosed by the plasma membrane, excluding the nucleus.
Dec 1411:21 PM
RibosomesRibosomes read the code in mRNA and synthesize protein accordingly.
=Ribosome
Protein Synthesis (Making)• The ribosome attaches to the mRNA• As ribosomes move along messenger RNA (mRNA), the amino acids are added to a growing chain to form a particular protein• When the ribosome reaches the end of the genetic message, it will become detached from the mRNA• A ribosome is composed of 2 subunits. In eukaryotic cells, the subunits are synthesized in the nucleolus and move into the cytoplasm.• During the process of protein synthesis, two subunits will come together along with mRNA
Dec 1411:30 PM
NucleolusThe nucleolus is a structure within the nucleus where the ribosomal subunits are produced.In cells that have been stained, it appears darker than the nucleus.
Dec 1411:30 PM
Endoplasmic ReticulumThe endoplasmic reticulum is a membranous network that extends throughout the cell.It is continuous with the nuclear envelope and the plasma membrane.
Rough Endoplasmic ReticulumThe rough appearance of rough endoplasmic reticulum is due to the presence of ribosomes on the membrane.The rough ER functions in protein synthesis, especially proteins that are to be secreted to outside the cell (example: hormones). Proteins enter the lumen (interior) of the endoplasmic reticulum while being synthesized. In addition to protein synthesis, the rough endoplasmic reticulum also functions in the modification of newly formed proteins. Example: some enzymes may add carbohydrate chains forming glycoproteins. Molecular chaperones are enzymes that function to fold the newlysynthesized proteins into their proper shape.Vesicles are small sacs that pinch off the endoplasmic reticulum or Golgi apparatus (discussed below) and transport molecules to other parts of the cell.
Smooth Endoplasmic ReticulumThe smooth endoplasmic reticulum contains passages that appear to be tubular in structure. The outer surface does not contain ribosomes so it appears to be smooth.
Smooth endoplasmic reticula are connected to rough endoplasmic reticula and, in most cells, the endoplasmic reticula are continuous with the nuclear envelope.
The smooth endoplasmic reticula have a variety of different functions. One important function is to produce lipid compounds such as phospholipids, steroids, and fatty acids.
Certain kinds of cells have smooth endoplasmic reticulum with a specialized function. The following are some examples: adrenal cortex and the testes where it produces steroid hormones.
The smooth endoplasmic reticulum of liver cells helps detoxify drugs in the blood.
Dec 1411:34 PM Dec 1411:34 PM
Golgi Complex (also Golgi Apparatus or Golgi Body)"FedEx of the Cell"
The Golgi complex is a stack of 3 to 20 flattened, slightly curved saccules which appear like a stack of pancakes.
Vesicles containing molecules from the endoplasmic reticulum arrive at the golgi complex. Chemical reactions within the Golgi complex modify the molecules
CellsIntro.notebook
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January 18, 2011
Nov 2411:18 AM
Aim: To create a "Help Wanted " poster for an organelle of a cell.
Include:Job Description
Experience
Job Requirements/ Abilities
Who (other cell parts) you need to work with
An illustration!Finish for homework
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Nov 249:56 AM
Nov 2410:02 AM Nov 249:22 AM
Nov 249:31 AM Nov 248:56 AM
• The endoplasmic reticulum (ER) is responsible for the production of the protein and lipid components of most of the cell's organelles. • ER contains a great amount of folds but the membrane forms a single sheet enclosing a single closed sac.
• Rough ER is the site of protein synthesis.• Smooth ER is where the vesicles carrying newly synthesized proteins (from the rough ER) are budded off.
CellsIntro.notebook
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January 18, 2011
Nov 248:39 AM Nov 2411:23 AM
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