Cells and Membranes Study Guide (Chapter 4 and 5)
When studying for your test tomorrow, review the following questions and review your notes, vocabulary worksheets, egg
osmosis lab, chapter 4 cell quiz, crossword puzzles, etc. The following are only examples of what you might see on your test.
Make sure you spend some time studying!
1. Discuss the similarities and differences between diffusion and osmosis.
Diffusion is the movement of molecules from an area of high to low concentration (in any medium...not
necessarily in liquid) either across a membrane or not.
Osmosis is the movement of water across a membrane from an area of high to low concentration.
2. Water generally travels from (hypertonic to hypotonic /
hypotonic to hypertonic) environments.
3. What would happen to a cell if placed in the following solutions?
a. Isotonic solution:cell mass stays same...water travels in and out equally
b. Hypotonic solution:cell mass increases...there is a net flow of water into the cell
c. Hypertonic solution:cell mass decreases...there is a net flow of water out of the cell
4. Intravenous solutions (IV Fluids) must be prepared so that they are isotonic to red blood cells. A 0.9 %
salt solution is isotonic to red blood cells.
a. Explain what will happen to a red blood cell placed in a solution of 99.3% water and 0.7% salt.
Since this is a hypotonic solution (lower amount of dissolved substances=higher amount of water),
water will flow into the cell. It will get larger and / or burst
b. Explain what would happen to a red blood cell placed in a solution of 90% water and 10% salt. Since
this is a hypertonic solution, water will flow out of the cell, and the cell will lose mass and shrivel.
c. What would happen to a red blood cell placed in a hypotonic solution? Same as letter “a” in this
problem
5. Describe a plant cell in a hypotonic solution. Why does it respond differently than an animal cell?
Since plant cells have cell walls, it is less likely for the plant cell to lyse (explode). The water just pushes
up against the cell wall and increases turgor pressure. This allows the plant to stand more rigid
6. Draw and describe a plant cell experiencing plasmolysis. What type of a solution (hypo, hyper, iso)
would cause plasmolysis?
A hypertonic solution causes plasmolysis.
Check out the diagrams to the left.
7. What are some ways animals have adapted to different osmotic conditions in their cells? (HINT: look in
your notes). 1. Your cells are bathed in blood (an isotonic solution) 2. Our kidneys help regulate the
water/salt balance 3. paramecium have a contractile vacuole that pumps water out if the cell's water
percentage gets too high. 4. Salt water fish are able to regulate salt balance by using their gills.
8. Explain, using pictures and terms mentioned in this sheet, what happens when salt is poured on a slug.
How will water move in relation to the slug's cells?
A) Water will move into the slug until an equilibrium is
reached.
B) Water will move out of the slug until an equilibrium
is reached.
C) Water will move into and out of the slug equally.
9. Use the following terms to create a concept map, an outline or a t-chart that shows how cells maintain
homeostasis: active transport, cell membrane transport, concentration gradient, diffusion,
endocytosis, exocytosis, facilitated diffusion, homeostasis, osmosis, passive transport, and sodiumpotassium pump, exocytosis, endocytosis, phagocytosis, pinocytosis
Cell Membrane Transport
I. Passive Transport: occurs with the concentration gradient
A. Diffusion: particles move from high to low until equilibrium is reached
B. Osmosis
C. Facilitated Diffusion
II. Active Transport: occurs against the concentration gradient
A. Endocytosis
i Phagocytosis
ii. Pinocytosis
B. Exocytosis
C. Protein and Ion pumps
I.Sodium-Potassium Pumps
10. Describe how a cell transports items out of the cell. Use words like active transport, vesicle, cell
membrane, exocytosis, etc. With very large items (sometimes) the cell needs to get rid of them.
Examples of items that need to exit the cell include wastes and hormones. The vesicle (with stuff
bundled inside) merges with the inside of the cell membrane. The membrane changes shape (which
requires energy aka active transport),and the items get “spit” out of the cell (aka exocytosis).
11. How does the sodium-potassium pump work? The sodium potassium pump pumps ___2___(#)
potassium ions (into / out of) the cell while it pumps __3___(#) sodium ions (into / out of) the cell.
12. Pumps are used by a cell to pump materials (up / down) their concentration gradient. Remember this
would mean from from a low concentration to a high concentration (the opposite of the way things
really work in nature)
13. Describe what happened to the shell-less eggs in hypotonic and hypertonic solutions. Eggs placed in a
(hypertonic / hypotonic) solution were likely to gain mass because water traveled (into / out of) the
egg.
14. When American pioneers moved west in the 19th century, they often preserved food, especially meat, by
burying it in casks of salt. Bacteria would land on the salt and would quickly die because water would
move out of them by osmosis. Dried, salted jerky is still very popular. How does the salt keep it
preserved? This is putting the cells into a hypertonic environments (high solutes, low water). Since
water moves from high to low, water will move out of the cell into the environment. And the cells
become “dehydrated” and preserved.
15. Know the parts and functions of the above cells AND words associated with cells including:
prokaryote, eukaryote, centriole, vacuole, ribosomes, rough ER, smooth ER, nucleus, nucleolus,
Golgi Complex, cytosol, cell wall, plasma membrane, capsule, fimbriae, flagella, plasmodesma,
chloroplast, central vacuole, lysosomes, peroxisomes, microtubules, microfilaments, vesicle,
cytoskeleton, nucleoid (bacteria), Cell Theory, etc.
Refer to various assignments/worksheets/etc. to study these
16. Try your hand at playing some of the review games too found at these links:
a. Flash cards (uncheck the box that says both sides and really quiz yourself!)
1. http://quizlet.com/5535796/holt-biology-chapter-3-cell-structure-flash-cards/
2. http://quizlet.com/1230402/passive-transport-flash-cards/
3. http://www.flashcardexchange.com/cards/pre-ap-biology-cell-parts-512482
b. You can also try out quiz games like the following:
1. http://www.quia.com/cb/25474.html
2. http://www.sciencegeek.net/Biology/review/U1Membranes.htm
17. You can also go to my website (near this week's lesson plans link) and open up the link that says “cell
parts memory game.” You can print out these cards, cut them out, and then test yourself matching them
over and over again. When you print them, functions will be correctly matched with the cell part!
18. Most importantly, refer to your cell quiz and your animal cell coloring. Also take a peek at your
bacterial cell coloring (prokaryote), your crosswords, and any other vocabulary items we completed
along the way.