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Section 3-Cells and the Cell Cycle: Part a
Take a narrated adventure inside the Cell!
Bio vision - Harvard university
Molecular and cellular biology learning center
CarnegieMellon - Cell Flash tutorials
What are the origins of cells? How did they come into existence?
Common features: All cells (prokaryotes & Eukaryotes) have several basic features in common.
1. All bound by a membrane - plasma membrane
2. All have genes made of DNA
3. All contain ribosomes - tiny structures that make proteins
Types of cells:
Prokaryotic cell - click on cell for larger image
1. Nucleoid region - coiled DNA
2. Cell wall - outside plasma membrane
3. Capsule - only in some, outside cell wall, sticky coating
4. Pili - short projections, help attach cell to surface
5. Flagella - propel cell through liquid environment
6. Ribosomes - protein production
7. Cytoplasm - inter membrane fluid
* Plant cells and animal cells are similar, but do not have exactly the same cell parts and shape.
Eukaryotic Cells - Click on each for enlarged view
Cell organelles: components of cells with specific functions.
1. Cell membrane (click on image)
A complex barrier of lipid molecules separating the cell from its external environment.
These molecules can move apart to allow larger particles to move in or out of the cell.
The "selectively permeable" cell membrane regulates what passes in and out of the cell.
A thick, aqueous solution of salts surrounding the organelles inside the cell membrane
Nutrients and minerals spread through the cytoplasm to all parts of the cell.
The structure inside the cell that directs cell activities.
Contains the DNA of a cell.
4. Cell wall
On the outside of some cells, bacteria and plants, this structure functions for support and protection.
There are pores in the cell wall allowing substances to come in contact with the cell membrane.
Types of cell walls:
Primary cell wall - formed during cell growth, it is composed of parallel layers of cellulose and pectin. This structure allows the cell to expand as it grows. While it does provide support, it is not nearly as strong as the secondary cell wall.
Secondary cell wall - formed after cell growth stops, it is composed of interwoven cellulose and lignin fibers. This structure is very strong, but does not give. It gives plants their "woody" characteristic.
The sites of protein synthesis in a cell.
These small, spherical structures are the most numerous organelles in almost all cells.
Some ribosome's produce protein to be used within the cell and some produce protein that is "exported" to other parts of an organism.
A membrane system of folded sacs and tunnels in the cytoplasm.
Rough "ER" is covered with ribosome's. It is common in cells that export proteins and directs the proteins flow.
Smooth "ER" as few or no ribosome's. It functions as a pathway for molecules to follow.
A stack of membranes or sacs that acts to prepare substances for export from the cell.
Once the Golgi apparatus has enclosed the final product in a vesicle, or pouch, the product is sent through the cell membrane.
Large organelles scattered through most cells, they are most numerous in cells that use a lot of energy like liver and muscle cells.
Respiration centers of a cell.
Digestive centers of a cell.
They contain many different types of enzymes and digest things from food particles (macromolecules) to a cell's own worn out parts.
Most common in plant cells, they are storage sites within a cell.
11. Chloroplast (Mostly found in plant cells and algae)
Performs photosynthesis - converting light energy into chemical energy.
Internal meshwork of protein fibers the provide structural support and involved in various types of cell movement.
Three mains types:
microfilaments - thinnest type, solid rods composed of actin (globular protein) twisted double chain, support cell shape
microtubules - thickest type, straight hollow tubes composed of globular proteins called tubulins, disassemble and reassemble, act as tracks for organelles
intermediate filaments - in between in thickness, made of fibrous protein, rope like structure, reinforce cell shape and anchor certain organelles
Flagella and Cilia - composed of microtubules wrapped in an extension of the plasma membrane
Provides locomotion in eukaryotic cells
1. Who developed the cell theory and in what year? What is the bases for this theory?
2. What hypothesis or theories suggest where cells originated? Protocells is one idea can you find another? Explain
3. What are the differences between a prokaryotic cell and eukaryotic cell. Include a diagram of each to support your answer.
4. Compare and contrast animal and plant cells, structurally how are they different?
5. Right click on this The living cell and "save target as" to your desk top. Once it has finished downloading view the video and complete the video quiz. Write the video quiz questions and answers with today’s assignment.
1. Visit this virtual cell web page Read the "how to use link" Using the virtual cell web page and the “School bus” link to complete this handout: Word doc. format pdf format: (when finished attached to the back of this assignment)
You have just been hired as an organelle sales person at Cell-to-Cells Sales Ind. You will be tasked with selling a particular cell organelle. How well do you know the function of cell organelles? Well you are going to need to know your organelles and cells because you are about to become a dealer in the competitive market of cell organelle sales.
As a side job to make extra cash you will also be working for Survivor Cells Corporation as a cell organelle buyer and construction manager. You will be be asked to develop a construction proposal to build a specific type of cell for the clients of Survivor Cells Corporation. Your CEO Steve Stemcell has more information on this task a this link .
|Section 3-Cells and the Cell Cycle: Part b|
Movement of substances in and out of the cell
Some substances, like water, move freely through the cell membrane by a process known as osmosis. In osmosis, particles move easily from an area of high concentration to an area of low concentration by molecular motion only. Cells can push particles in the opposite direction, from low concentration to high, but it will take energy from the cell to do this.
Passive Transport-Passive transport does not require energy.
Types of passive transport:
Active Transport- requires energy.
Other types of Transport
Practice with Diffusion and Osmosis
Check out these videos that will help you understand the complex cell membrane
Assignment 1.3b - Cells and the Cell Cycle
1. Read through Membrane Structure concept 1 and the review.
2. Read through Osmosis concept 2 and the review.
3. Read through Selective Permeability of Membranes concept 3 and the review.
4. Read through Passive and Active Transport concept 4 and the review.
5. Concept 5 Mechanisms of Active Transport goes above and beyond what is required for this class but you can take a look at it if you would like.
6. Complete the practice quiz at the end and write your answers here (questions 10, 11, 14, & 15 come from concept 5 and can be done to go above and beyond what is required)
Section 3-Cells and the Cell Cycle: Part c
What group of cells in the human body does not have a nucleus?
Size of living things:
The smallest known living thing on Earth is a bacteria in the genus Coxiella. These bacteria are about 8 millionths of an inch (0.2 micrometers) in diameter. Their small size means these bacteria contain only 100 million to 120 million atoms. While this may seem like a large number, keep in mind that the human body has over 5 Billion cells. It is believed that fewer atoms would be unable to build the structures needed to store information and carry out the metabolic processes needed for life.
The largest known animal is the blue whale, Balaenoptera musculus. It is known to reach lengths over 100 feet (30+ meters) and weigh 120 tons. The chart below indicates that all animal cells are about 10 micrometers in diameter. This means that the cells of a blue whale and a human are essentially the same size.
Assignment 1.3c - Cells
and the Cell Cycle
Honors biology: Read honors section below first.
Question: Would a cell survive if it grew to be the size of your head?
Explain your hypothesis:
1. Draw a table like this one on your paper or print this word doc. of the table and use your data and calculations to complete it.
2. Measure and record the diameter of a large marble, a ping-pong ball, and a baseball, in centimeters.
3. Calculate the surface area and volume of each object.
1. Show how you set up the following calculations on your paper.
2. Use 3.14 for in these calculations.
3. The formula for calculating the surface area of a sphere is
surface area = 4 r 2
4. The formula for calculating the volume of a sphere is
V = 4/3 r 3
*After completing the table, use your findings to write an explanation and conclusion for the question.
Honors biology: Instead of doing the table above print out this Cell size lab for class. Word doc. or web page version. Read the lab carefully and complete the pre-lab portion before we begin the experiment portion.
Webcytology Simulation - Create your own unicellular species
Cellular Biology - Altruis Biomedical Network
Biology 100 - Wayne's World
The Cell - Thinkquest
Cell Structure - Carroll College
Cell Biochemistry - Carroll College
Virtual Cell - Virtual Cell
The Cell Nucleus - University of Texas Medical Branch at Galveston
Cell Membranes - Texas A&M University
Cells Alive - By James A. Sullivan
Cell & Molecular Biology Online - Links by Pamela Gannon
Cell Biology Hypertextbook - Massachusetts Institute of Technology
Digital Learning Center for Microbial Ecology - Michigan State University
Cell Membrane Tutorial - The Biology Project
Red blood cells do not have a
They are produced in the "flat" bones of the body, live for about 120 days, and die without reproducing. Their sole purpose is to carry oxygen and carbon dioxide in the blood.