Download Biology: Assignment #4 Cell Membrane

Biology: Assignment #4 Cell Membrane
Root Words: For the following root words, define the term and provide an example of a
biological term that incorporates the root word.
Term
1. Iso -
Definition
Example
2. -lys
3. Adip 4. Amphi 5. Ecto 6. Endo 7. Extra 8. Gluc 9. Hydr 10. Hypo 11. Hyper 12. Inter 13. Intra 14. Trans 15. Sacchar Vocabulary: For each word pair below, define both words, and then form a complete
sentence that uses both terms. The sentence must explain a concept.
1. Concentration Gradient – Passive Transport
a. Concentration Gradient Definition: _______________________________
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b. Passive Transport Definition: ___________________________________
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c. Sentence: __________________________________________________
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Biology: Assignment #4 Cell Membrane
2. Active Transport – ATP
a. Active Transport Definition: _____________________________________
___________________________________________________________
b. ATP Definition: ______________________________________________
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c. Sentence: __________________________________________________
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True/False: Determine whether the following statements are true or false. Correct the
underlined term of each false statement to make it a true statement.
1. _____ The cell wall regulates what enters and leaves the cell.
2. _____ Plant cell walls are comprised of cellulose.
3. _____ The process of particles moving from a high concentration to a lower
concentration is osmosis.
4. _____ Osmosis is the diffusion of salt through a membrane.
5. _____ Cell membranes are composed of a phospholipid trilayer.
6. _____ Passive transport requires ATP.
7. _____ In a hypertonic environment, plant cells wilt.
8. _____ In a hypertonic environment, animal cells lyse.
Biology: Assignment #4 Cell Membrane
Reading Comprehension: Read the following excerpt and answer the questions that
follow.
“All living things are made up of tiny units called cells. The cells are surrounded by a
covering called a membrane. The membrane controls what moves in and out of the cell.
Cells need many kinds of materials in order to thrive. They must have water, oxygen,
glucose (sugar), sodium, potassium and a variety of other minerals. The body has to
have a delivery system to get these materials where they need to go. In addition, every
cell produces waste materials that it needs to get rid of. The body has to have a method
of waste collection and disposal. Like a fleet of trucks form a transport system to the
pickup and deliver goods in the world, the body has a transport system, too. There are
two types of transport: active transport, and passive transport.
Passive transport is easiest for the cells because they don’t need to use any energy to
make it happen. Diffusion is the simplest and most common form of passive transport.
During the diffusion process, tiny particles of the materials that need to be delivered to
the cells are spread through either a gas, like oxygen, or a liquid, like water. Areas with
high concentrations of the materials slowly diffuse them to areas of low concentration of
the materials. Osmosis is a unique form of passive transport that allows water to pass
through the cell membrane but keeps most other materials out.
Active transport is used when the concentration of materials inside the cell is high, and
the cell needs to push materials out to areas of low concentration of the materials.
Unfortunately, this kind of transport requires the cell to work against the natural direction
of diffusion. This causes the cell use energy. One example of this is how nerve cells
work. They pump sodium out and pull potassium in. Although they must expend energy
in this process, doing so allows them to thrive.” –copyright ©2012 K12Reader, online
1. In this passage, terms are placed in bold print. What purpose do these serve in
readings like this?
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________________________________________________________________
2. Explain why it is easier for cells to carry out passive transport rather than active
transport.
________________________________________________________________
________________________________________________________________
3. Explain the term “concentration.” Why does the concentration gradient of
molecules determine whether active or passive transport must occur?
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Biology: Assignment #4 Cell Membrane
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Diagram: Create drawings in the spaces below that demonstrate what would happen to
the cell pictured in each of the following conditions. Be sure to label the solution as
isotonic, hypertonic, or hypotonic and include arrows that show the movement of water.
Recall that osmosis refers to the movement of water across a membrane!
Cell Water
Concentration:
15%
Draw and label a diagram of
what would happen to the cell
if it was placed into the
solution below.
Beaker: 10% water,
90% solute
Draw and label a diagram of
what would happen to the cell
if it was placed into the
solution below.
Draw and label a diagram of
what would happen to the cell
if it was placed into the
solution below.
Beaker: 45% water,
55% solute
Beaker: 85% solute
Multiple Choice Skills: For the following question, circle the correct answer. Underline
the word or phrase in the question or answer choice that led you to this decision. In the
box to the right, explain why the answer choice is correct or why the other choices are
incorrect.
1. A cell is placed into a salt solution. The salt
concentration is greater in the solution than inside
the cell. Which best describes what will most likely
happen?
Explanation:
Biology: Assignment #4 Cell Membrane
a.
b.
c.
d.
Water will flow into the cell by active transport.
Water will flow into the cell by passive transport.
Water will flow out of the cell by active transport.
Water will flow out of the cell by passive transport.