Biol 12
Review: Structures of the Cell and Cell Membranes
Sections 1-1, (1-4-phospholipids), 1-5
1
A. Review Questions: With the exception of the blanks, you are not required to answer this set
of questions. However, I highly recommend you go through the questions, and be sure that
you are ABLE to answer them.
1.
2.
3.
4.
5.
List the major chemical components found in animal cell membranes.
Which part of the cell functions as a control centre? Which molecule directs protein synthesis?
What is the difference between chromatin and chromosomes?
What is the role of the nucleoli in the cell?
are the dense granules composed of
subunits that contain both RNA and
.
They are the sites of
synthesis. When several ribosomes are making the same protein, they
are arranged in a functional group called a
.
6. What is the structural difference between rough and smooth endoplasmic reticulum?
7. List 2 functions of smooth endoplasmic reticulum.
8. Ribosomes attached to the endoplasmic reticulum produce protein that is destined for
.
9. How does the ER server as a transport system?
10. Describe the appearance and give the function of the Golgi apparatus.
11. What is the difference between a vacuole and a vesicle?
12. Lysosomes contain
enzymes that digest macromolecules. Why is autodigestion important?
13. List the 2 energy-related organelles of the cell?
14. Describe the structure of the mitochondria. Why is it important to the cell?
B. Objective Test - completion and short answer questions.
1. Nucleus. The nucleus is enclosed by the (a)
, which contains (b)
that open into the cytoplasm. At the time of cell division, chromatin (c)
to form chromosomes. The relationship between the nucleoli and
ribosomes is (d)
. DNA within the nucleus
controls (e)
.
2. Name the organelles in this drawing of an animal cell.
Review: Structures of the Cell and Cell Membranes
Sections 1-1, (1-4-phospholipids), 1-5
Biol 12
3. Which
structures in a cell contain DNA?
RNA?
5. What are hydrolytic enzymes, and which organelle contains them?
6. How is the cell membrane and the nuclear membrane similar? How are they
different?
7. Togetherness. How do these organelles work together?
a. lysosomes and vacuoles.
b. endoplasmic reticulum + membranes
c. ribosomes and endoplasmic reticulum.
d. chloroplasts and mitochondria.
e. Golgi Bodies and Endoplasmic Reticulum.
c. Matching
packaging and secretion
a. mitochondria
hydrolytic enzymes
b. ribosomes
energy production
c. lysosomes
protein synthesis
d. rough endoplasmic reticulum
membrane synthesis
e. Golgi Apparatus
protein transport
f. smooth endoplasmic reticulum
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3
Review: Structures of the Cell and Cell Membranes
Sections 1-1, (1-4-phospholipids), 1-5
Biol 12
d. Fill in the Blanks
1.
is an organelle that is thought to have a roll in detoxification of drugs.
2.
enzymes.
is an organelle in which digestion takes place due to the action of powerful hydrolytic
3.
is a threadlike network in the nucleus that is made up of DNA and proteins.
4.
is a structure that is made up of phospholipids, cholesterol and proteins.
5.
is the component of cell membranes that causes them to have a consistency of light oil.
6. The cristae in mitochondria are used for the production of
by means of
respiration.
Cell Membranes: Review Questions:
1. In particular, what does the cell membrane regulate? What is it largely responsible for?
2. Describe the fluid mosaic model. Which part of the phospholipid faces outward and is attracted to water?
3. The basic structure of the cell membrane is determined by the
but the various
functions of the membrane are carried out by the cell membrane
.
4. Give 4 functions of proteins in the membrane.
5. Which type of molecule is easiest to cross a cell membrane, a small non-charged substance soluble in lipid, or
a large, charged molecule?
6. Why is the cell membrane said to be differentially permeable? What is the difference between a passive and
active means in order to assist the passage of molecules across the cell membrane?
7. Is the cell membrane positively or negatively charged on the outside? On the inside?
8. Define diffusion and give an example.
9. Why do lipid-soluble molecules, such as alcohol and gases, diffuse through the cell membrane?
10. Explain why water molecules pass into and out of the cell membrane with relative ease.
11. Define osmosis.
12. What is an isotonic solution? Will water leave the cell?
13. What is a hypotonic solution? Will more water enter or leave the cell? What will happen to an animal cell?
What term is used to describe disrupted red blood cells?
14. What is a hypertonic solution? Will more water enter or leave the cell? What will happen to an animal cell?
What term is used to describe the shrinking of the cytoplasm due to osmosis?
15. Carrier proteins in a cell membrane are required for what 2 types of transport?
16. Describe facilitated diffusion. Does it require energy? Do the molecules move down or up the concentration
gradient?
17. Define active transport. Does it require energy? Do molecules move down the concentration gradient?
18. The sodium-potassium pump will create a high concentration of
ions outside the cell and
ions inside the cell.
19. What is the difference between endocytosis and exocytosis?
20. Explain the difference between phagocytosis and pinocytosis. Give an example of each.
21. Name the organelle that will form vesicles used for exocytosis. Exocytosis is required for
.
B. Objective Test - Completion and short answer Questions.
1. Diffusion is the movement of molecules from the area of
to the area of
concentration.
concentration
Biol 12
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Review: Structures of the Cell and Cell Membranes
Sections 1-1, (1-4-phospholipids), 1-5
2. Osmosis is the movement of
across a differentially permeable membrane.
3. A cell is isotonic to a solution of 0.01% sugar. A concentration that is hypertonic is
, whereas a concentration that is hypotonic is
.
4. If an animal cell is placed in a hypotonic solution, it would
whereas an animal cell placed in hypertonic solution would
.
5. Cells engaged in the process of actively transporting substances across the
membrane expend
.
6. Label this diagram of the cell membrane:
8. Give an example of :
a. diffusion in the body:
b. facilitated diffusion:
c. active transport:
9. List three ways in which active transport differs from the process of diffusion across a
cell membrane.
a.
b.
c.
Biol 12
Review: Structures of the Cell and Cell Membranes
Sections 1-1, (1-4-phospholipids), 1-5
10. List two ways in which facilitated diffusion differs from active transport.
a.
b.
11. By which method would you predict that these molecules would enter a cell?
a. oxygen
b. glucose
+
c. potassium (K )
c. water
12. Consider this diagram. The membrane is differentially permeable to glucose and
water but not to protein.
a. Will the concentration of water stay the same on side A or become greater or less
with time?
b. Will the concentration of protein on side A stay the same or become greater or less
with time?
c. Glucose will cross the membrane in which direction?
d. On which side will the hydrostatic pressure increase?
e. What will happen to the level of the solution on each side?
14. Red blood cells neither gain nor lose water when put into 0.9% NaCl.
a. What term is used to designate the tonicity of 0.9% NaCl for red blood cell?
b. Are the solutions below hypertonic or hypotonic to red blood cells?
15% NaCl
0.001% NaCl
c. Beside the words below write either 0.9% NaCl, 15% NaCl, or 0.001% NaCl.
Hemolysis
crenation
neither of these
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Biol 12
Review: Structures of the Cell and Cell Membranes
Sections 1-1, (1-4-phospholipids), 1-5
6
15. Sea urchin egg are isotonic to seawater. Consider these conditions:
(1) Eggs are in seawater.
(2) Eggs are in 65% seawater (35% distilled water)
(3) Eggs are in pure distilled.
True (T) or False (F)
a. Under condition 1, the system is already in equilibrium.
b. Under condition 2, the eggs will swell.
c. Under condition 3, the eggs will shrink.
16. Transport
a. A scientist notes that of three monosaccharides - glucose, mannose, and galactose glucose enters cells much faster than the other two. What process is at work?
b. A scientist determines that the concentration of phosphates outside a cell is 5 mg/L
and inside the cell it is 75 mg/L. By the law of diffusion, which way would you predict
phosphate to go - in or out of the cell?
The scientist notes that the cell
continues to accumulate phosphates. What mechanism is at work?
Completion Question.
17.
is a fluid such as water that dissolves solutes.
18.
is the contraction of cell contents due to loss of water.
19.
is the movement of molecules from an area of greater
concentration to an area of lesser concentration.
20.
is a lipid molecule that lends stability to the
phospholipid bilayer.
True or False.
If you believe the statement to be false, then rewrite the statement as a true one.
22. If a red blood cell is placed in distilled water, it will shrink.
Answer:
Restatement:
23. If a red blood cell is placed in a high salt solution, salt will enter the cells, giving them
a strange appearance.
Answer:
Restatement:
24. If a cell uses active transport to take in salts, then osmosis will follow.
Answer:
Restatement: