Euan Morton and Jayden Jumbo
Period 5
Unit 2: Cell Structure and Function
Cell Classification
1. What is the difference between a prokaryote and a eukaryote? The difference
between a prokaryote and a eukaryote is that eukaryotes have a nucleus,
membrane-bound organelles, and DNA is enclosed within the nucleus; they are also
generally larger and more complex. Whereas prokaryotes lack a nucleus
membrane-bound organelles, and DNA is free-floating in the cytoplasm; they are also
usually smaller and simpler.
2. Give examples of each. An example of a prokaryote is Escherichia coli, a bacteria.
An example of a eukaryote is a liver cell in the human body, an animal cell.
3. Give four differences between plant and animal cells. Four differences between plant
and animal cells are; plant cells have a cell wall while animal cells do not, plant cells
have a chloroplast while animal cells do not, plant cells have a large central vacuole
while animal cells have smaller temporary vacuoles, and animal cells have centrioles
while plant cells do not.
Cell Membrane Structure
4. Draw a section of the plasma membrane. Label and provide the function of the
following structures: a. Phospholipids b. Hydrophilic heads c. Hydrophobic tails d.
Cholesterol e. Integral and transmembrane proteins: channel, transport, electron
transport (see chemiosmosis) f. Peripheral proteins: recognition, receptor, and
adhesion
Functions: a. Phospholipids: Form bilayer (hydrophilic heads face out, hydrophobic tails
in)
b. Hydrophilic heads: Attracted to water, face outward.
c. Hydrophobic tails: Repel water, face inward.
d. Cholesterol: Stabilizes membrane fluidity
e. Integral and transmembrane proteins: channel, transport, electron transport (see
chemiosmosis): Channel proteins; allow specific ions/molecules through, Transport
proteins; move substances across, and Electron transport proteins; part of cellular
respiration (in mitochondria).
f. Peripheral proteins: recognition, receptor, and adhesion: Recognition, identify cell
type, Receptor, receive signals, and Adhesion: helps cells stick together.
Cell organelles
5.Cut and paste a picture of the plant and the animal cell and beside each label listed
below, provide the functions of the organelles. You may need to draw some in. a.
Nucleus b. Ribosomes c. Rough ER d. Smooth ER e. Golgi body f. Vesicles g.
Mitochondria h. Chloroplasts i. Lysosomes j. Centrioles k. Vacuoles l. Flagella m. Cilia n.
Cell Wall
Function: a. Nucleus: Stores DNA; controls cell activities
b. Ribosomes: Synthesize proteins
c. Rough ER: Has ribosomes; processes proteins
d. Smooth ER: Synthesizes lipids; detoxifies
e. Golgi body: Modifies, packages, and ships proteins
f. Vesicles: Transport materials in the cell
g. Mitochondria: Produce energy (ATP) via cellular respiration
h. Chloroplasts: Photosynthesis (in plants)
i. Lysosomes: Digest waste and worn-out parts
j. Centrioles: Help in cell division (animal cells)
k. Vacuoles: Storage of water, nutrients, waste
l. Flagella: Tail-like; helps with movement
m. Cilia: Hair-like; move fluid or cell
n. Cell Wall: Provides structure and support (plant cells)
6.Provide the types of cell junctions and explain their importance.
Tight junctions; seal cells together to prevent any leakage through selective barriers that
maintain homeostasis by making sure proteins do not mix, for example in intestines.
Desmosomes: Strong adhesion; hold cells together under stress by acting as sort of
anchor that connects the cytoskeletons of cells together, for example skin cells. Gap
junctions: channels for communication between cells by facilitating the rapid movement
of molecules through small gaps, for example heart cells.
7.Describe the following components of a cell’s cytoskeleton: microtubules,
intermediate filaments, and microfilaments.
Microtubules: These are hollow tubes that maintain cell shape and help the cell in
division and transport. Intermediate filaments: These provide tensile strength to the cell
and stabilize the organelles within the cell. Microfilaments (Actin): These are thin fibers
that help in movement and shape changes in the cell.
Cell Membrane Function
8.What does it mean that the cell membrane is selectively permeable?
It means the cell membrane allows some substances to pass while at the same time
blocking others, this maintains the internal balance of the cell by making sure it can
intake what it needs and keep out what it does not.
9.Create a chart comparing the following processes: diffusion, osmosis, facilitated
diffusion, and active transport. Include the following in your chart: a. passive or active b.
with or against the gradient c. proteins or no proteins involved d. if proteins are involved,
what type e. substances moved by each process
Process Passive/Active With/Against Proteins Type of Substances
Gradient Used Proteins Moved
Diffusion Passive With No None Gases
Osmosis Passive With Yes/No Channel Water
(aquaporins
may help but
are not
needed)
Facilitated Passive With Yes Carrier/ Ions,
Diffusion Channel glucose
Active Active Against Yes Carrier Ions,
Transport nutrients
10.Draw and describe a cell in a hypertonic, hypotonic, and isotonic solution. Explain
osmosis in each solution.
Hypertonic: Too much water leaves cells causing the cell to shrink, examples are
crenation/plasmolysis. Hypotonic: Too much water enters causing the cell to swell, this
may lead to the cell bursting. Isotonic: There is no net water movement this causes the
cell stays same size
11.Describe the process of plasmolysis
In plasmolysis there is a loss of water from plant cells in a hypertonic solution that then
causes the cell membrane to pull away from the cell wall.
12.Vesicular transport: Draw and describe the processes of exocytosis, endocytosis
(phagocytosis and pinocytosis)
Exocytosis: The vesicle of the cell fuses with the cell membrane this releases the
contents of the vesicle outside the cell. Endocytosis: The membrane engulfs materials
which then forms the vesicle of the cell. Phagocytosis: This is pretty much cell eating
when a cell engulfs solid particles and then digests it. Pinocytosis: This is pretty much
cell drinking when a cell takes in extracellular liquids into itself.
