Biology: Unit 3: Cells Study Guide
Use your notes and your knowledge of Biology to define the following terms:
Osmosis-movement of water molecules from
an area of high to low concentration without
energy.
Passive Transport-the movement of molecules
from high concentration to low concentration
without energy.
Pinocytosis-The most common form of
endocytosis, that takes in dissolved
molecules in water through a vesicle. “Cell
drinking”
Phagocytosis-when large molecules such as
food, bacteria, etc. are taken into the cell
through vesicles and referred to as “Cell
Eating”
Prokaryote- Have very few organelles (parts),
they don’t have a nucleus, and they are
primitive cells (bacteria).
Endocytosis- molecules move in the cell.
Concentration Gradient- is the difference in the
concentration of a substance between two
areas
Hypotonic- have less amount of solute (salt)
outside of the cell compared to inside.
Exocytosis- takes out large molecules from the
cell that are manufactured in the cell.
Eukaryote- Have many organelles (parts),
they have a nucleus, and they are modern
cells (Plants and animals).
Simple Diffusion- the movement of small and
the large hydrophobic, or lipid soluble
molecules from an area of high to low
concentration without energy.
Facilitated Diffusion- the movement of large or
small hydrophilic, or ion molecules from an
area of high to low concentration through
transport proteins without energy.
Isotonic- an equal amount of solute (salt)
outside and inside the cell.
Active Transport- Molecules move from low
concentration to high concentration with
energy (ATP), and against the concentration
gradient.
Selectively Permeable- Feature of the plasma
membrane that maintains homeostasis with a
cell by allowing some molecules to pass
through the cell membrane while keeping
others out.
Hypertonic- have a greater amount of solutes
(salt) on the outside of the cell compared to
the inside.
Use your notes and your knowledge of Biology to answer the following questions:
History of Cells
1. What is the cell theory?
a.
That all living things are made of cells.
b. That cells are the basic unit of structure and function of living things
c. New cells come from pre-existing cells.
2. Match the Scientist to their contribution to the cell theory:
a. Hans and Jansen
_b___ Named cells
b. Hooke
__c__ Bacteria
Biology: Unit 3: Cells Study Guide
c.
d.
e.
f.
Leeuwenhoek
Schleilden
Schwann
Virchow
__f__
_a___
__e__
_d___
Cells come from pre-existing cells
First compound microscope
Animals are made of cells
Plants are made of cells
Cell Organelles: Match the organelles to their functions
a. Cilia
motion
b. Plastid
c. Cytoplasm
d. Flagella
e. Cell Wall
f. Nuclear Membrane
g. Cell Membrane
h. Nucleus
i. Nucleolus
j. Endoplasmic Reticulum
k. Golgi Apparatus
powerhouse
l. Chloroplast
m. Ribosome
n. Vacuole
o. Lysosome
p. Mitochondria
_a___ Hair like projections that aid with
_c___
_o___
_d___
_b___
_i___
_l___
_e___
_h___
_k___
__p__
Jelly-like fluid that surrounds cell
Cleans up waste in cell, digestion
Long tail like structure for movement
Small structure that stores food
Small body in nucleus, makes ribosomes
Converts energy through photosynthesis
Rigid, porous outer layer of the plant cell
Directs cell’s activities, contains DNA
Packages and ships
Energy is created for the cell,
_f___
_j___
__g__
_m__
_n___
Surrounds and protects the nucleus
Transports proteins around the cell
Controls what enters/exits cell
Synthesizes proteins
Stores water
Cell Membrane
1. What are the reasons the plasma membrane is referred to as a fluid mosaic structure?
Fluid, because individual phospholipids and proteins can move side-to-side as if they are in liquid
and a mosaic, because of the collection of components that make it up. ____________
2. How does the cell membrane function to help a cell maintain homeostasis?
The cell membrane functions include protecting the cell, allowing molecules to enter and exit the
cell, and it allows cell to cell communication.____________________
3. How do molecules enter and exit the cell? __
The cell membrane is permeable
4. How are the phospholipids uniquely positioned to allow hydrophobic molecules through?
Across the Cell (Plasma) Membrane: The structure of the lipid bilayer allows small, uncharged
substances such as oxygen and carbon dioxide, and hydrophobic molecules such as lipids, to pass
through the cell membrane, down their concentration gradient, by simple diffusion.
_____________________ _
5. What is the difference between hydrophobic heads and hydrophilic tails?
Hydrophobic heads are non-polar and doesn’t let water through and hydrophilic tails is polar and
likes water so it lets it through
Biology: Unit 3: Cells Study Guide
6. How do the large molecules enter and exit the cell?
Large polar and ion molecules use the transport proteins that serve as a pathway. ___________
7. How do cells communicate with one another?
Carbohydrates are the receptors on the cell membrane surface that allow cell to cell
communication.
Cell Transport
1. What are the two types of cell transport? _____passive and active
transport_____________________
2. How do molecules move by passive transport? __molecules move from high concentration to
low concentration without energy by using their natural kinetic energy and go with the
concentration gradient____
3. How do molecules move by active transport? _molecules move from low concentration to high
concentration with energy (ATP) and against the concentration with the concentration
gradient_________________________
4. Which type of transport requires energy (ATP)? ______active
transport________________________________
5. What are the different forms of passive transport? ___simple diffusion and facilitated
diffusion______
6. What do channel proteins do? __They are embedded in the cell membrane and have pore for
materials to cross___
7. What do carrier proteins do? _They can change shape and bond to molecules to move them
from one side to the other__
8. What type of passive transport moves from high to low concentration without energy and
without an aid? _simple diffusion
9. What type of passive transport moves from high to low concentration without energy, but
contains larger molecules so they need an aid (transport protein) to help them pass?
___________ facilitated diffusion____________
***When reviewing and completing your test, pay close attention to where the higher
concentration of the MOLECULES are and decide whether it is active or passive transport. Would
it require energy because it is going from a lower to a higher concentration, etc. Look for ATP in
pictures, look for transport proteins, count the number of molcules, etc. ***
10. Does diffusion ever stop? Why? __It never stops since molecules always have natural kinetic
energy________
11. Can dynamic equilibrium ever be reached? Why? _No, since molecules always have natural
kinetic energy________
Biology: Unit 3: Cells Study Guide
12. Is osmosis passive or active transport? Why? ___Osmosis is passive because the water
molecules move from an area of high to low concentration without
energy_______________________________________
13. List whether the following pictures are hypotonic, isotonic, or hypertonic and show which way
the water is moving.
______hypertonic__________
______hypotonic_________ _____isotonic______
14. Why don’t plant cells burst from osmosis? ____because they have a cell
wall______________________________________
15. Where did someone go swimming if their blood cells are shriveled up? _salt
water__________________
16. Where did someone go swimming if their blood cells are swollen? ___fresh
water____________________
17. What are the different types of active transport for the movement of large molecules?
___endocytosis-molecules move in the cell and Exocytosis- molecules move out of the
cell______
Surface Area and Volume
1. How does the size of the elephant and the mouse cells compare? They have the same cell size
2. Which organism is better able to maintain homeostasis, an organism with one large cell or an
organism with several smaller cells? Why? _the smaller and more abundant cells are able to
maintain homeostasis because there is more of them to work together at maintaining cell
homeostasis_________
3. Which cell below do you think has more surface area, assuming they have the same volume?
First one
4. Why is it best that cells divide rather than grow in size? ___if cells grow in size would be less
cells to work together to maintain homeostasis and the larger cells are less efficient at
transporting molecules______________________________