Download Cell Wall: Cell membranes surround every cell you will study. Cell

Name: ____________________________
Cell structure and function 1 H.W due Friday Sept. 16
Read the information below and answer the questions.
Cell membrane: According to cell theory, cells are the main unit of organization in biology. Whether you
are a single cell or a blue whale with trillions of cells, you are still made of cells. All cells are contained by a
cell membrane that keeps the pieces inside. When you think about a membrane, imagine it is like a big
plastic bag with some tiny holes. That bag holds all of the cell pieces and fluids inside the cell and keeps
any nasty things outside the cell. The holes are there to let some things move in and out of the cell. It is a
thin, structured layer of lipid and protein molecules that controls what moves in and out. In animal cells,
the membrane establishes this separation alone, whereas in yeast, bacteria and plants an additional cell
wall forms the outermost boundary, providing primarily mechanical support.
Cell Wall: Cell membranes surround every cell you will study. Cell walls made of cellulose are only found
around plant cells and a few other organisms. If a plant cell is like a water balloon, the cell wall is like a cardboard
box that protects the balloon. The balloon is protected from the outside world by a structure that provides
protection and support. While cell walls protect the cells, they also allow plants to grow to great heights. You
have a skeleton to hold you up. A 100-foot tall redwood tree does not. It uses the strong cell walls to maintain its
shape.
Cytoplasm: It is the fluid that fills a cell. This jelly that fills the inside of a cell is called cytoplasm. Cytoplasm
helps to hold the cell's organelles (small organs) in place. As you travel through the cell membrane and enter
the cell, you will find yourself floating in a kind of jelly. Cytoplasm also gives the cell structure. Think of a
balloon. An empty balloon does not have much structure. However, if we fill it with something, like water, it
begins to take shape.
Nucleus: The cell nucleus acts like the brain of the cell. It controls the activities of the cell. If it happens in a
cell, chances are the nucleus knows about it. The nucleus is not always in the center of the cell. It will be a big
dark spot somewhere in the middle of all of the cytoplasm (cytosol). You probably won't find it near the edge
of a cell because that might be a dangerous place for the nucleus to be. If you don't remember, the cytoplasm
is the fluid that fills cells. The nucleus holds genetic materials (DNA, genes, chromosomes) in plants and
animal cells.
Vacuoles are storage bubbles found in cells. They are found in both animal and plant cells but are much
larger in plant cells. Vacuoles might store food or any variety of nutrients a cell might need to survive. They
can even store waste products so the rest of the cell is protected from contamination. Eventually, those
waste products would be sent out of the cell. It is like a pantry that stores food and water. It also acts like
your stomach that stores food and water.
1. According to the cell theory, __________________ are made of __________.
2. What is the function (job) of the cell membrane?
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______________
3. The cell membrane is like a ___________________.
4. True/False. Every cell has a cell membrane. ___________.
5. True / False. Plant cell has a cell membrane. ___________.
6. What is the function of the cell wall?
____________________________________________________________________________________
____________________________________________________________________________________
7. The cell wall is like a ___________________.
8. True/False. Cell wall is found in an animal cell. __________
9. What is cytoplasm?
____________________________________________________________________________________
10. What is the function of the cytoplasm?
____________________________________________________________________________________
11. The cytoplasm is like a ___________________.
12. What is the function of the nucleus?
____________________________________________________________________________________
13. What does the nucleus hold? ______________________________________
14. Do plant cells have nucleus? _________________
15. What is the function of the vacuole?
____________________________________________________________________________________
16. Vacuole is like a ______________________.
17. True/False. Plant cells have a larger vacuole than animal cell. _________
Draw plant and animal cell and label the following structures: cell membrane, cell wall, cytoplasm, nucleus,
and vacuole.
Plant cell
http://www.biology4kids.com/files/cell_membrane.html
http://www.kids.net.au/encyclopedia-wiki/ce/Cell_membrane
Animal cell