Ch 3 Cell Structure & Function Study Guide
1. Contrast 3 differences between prokaryotic and eukaryotic cells.
Prokaryotic - small, simple, no organelles.
Eukaryotic - large, complex, with organelles.
a. What is the most prominent difference?
SIZE
b. Identify 3 structures that are found in both prokaryotic and eukaryotic cells.
Flagella, plasma membrane, cytoplasm, ribosomes, chromosomes, DNA.
2. Define what is an organelle?
Wrapped in their own membrane inside the membrane surrounding the entire cell.
Perform specific functions.
Give some examples.
Mitochondria, lysosomes, nucleus, golgi complex, etc.
Is a ribosome an organelle?
No, it does not have its own membrane.
3. For the 3 main parts of a cell:
a. Identify the name of the structure that wraps around the cell.
1.) Plasma membrane
2.) Nucleus
3.) Cytoplasm
b. Identify the fluid that fills the inside of the cell, and the 2 components in the fluid:
Cytoplasm - 1.) Cytosol, 2.) organelles.
1
,c. Describe the composition of the cytosol:
Water and dissolved components.
i. What is the percent of water?
75-90%
4. Identify the general functions of the cytoskeleton protein filaments.
Cell support and shape.
Organization of chemical reactions.
Movement of molecules in cells.
5. For cytoskeleton microfilaments:
a. Identify an example of microfilament proteins and types of cells where they are found.
Composed of actin and myosin.
b. What is the function of the microfilament proteins for your example?
Involved in muscle contraction.
6. Identify a function of intermediate cytoskeleton filaments.
Glues cells together.
7. For microtubules:
a. Identify 3 movement structures composed of microtubules and examples of cells
where they are found.
1.) Spindles
2.) Cilia
3.) Flagella
Found in sperm.
b. Identify the microtubules that are formed by the centrioles and the purpose.
Centrosomes - Formation sight for mitotic spindles during cell division.
2
, 8. For ribosomes:
a. Describe the composition of the structure.
2 subunits - rRNA and protein
b. Identify the function of ribosomes.
Site for protein synthesis; connects amino acids using instructions from DNA genes.
c. Which monomers are connected by ribosomes?
Amino acids
d. Where do the instructions come from for this function?
DNA genes
e. Where are 2 places in the cell where ribosomes are found?
Inside cytoplasm (free ribosomes) and attached to endoplasmic reticulum (bound
ribosomes).
f. How many ribosomes are found in human cells?
1000’s
9. For endoplasmic reticulum (ER):
a. Where in the cell is ER found?
Surrounding the nucleus.
b. What is attached to some types of ER?
Ribosomes
c. What is the function of rough ER?
Modifies molecules and connects proteins with other molecules.
d. What is the function of smooth ER?
Detoxifies harmful substances like drugs and synthesizes steroids and fatty acids.
3
1. Contrast 3 differences between prokaryotic and eukaryotic cells.
Prokaryotic - small, simple, no organelles.
Eukaryotic - large, complex, with organelles.
a. What is the most prominent difference?
SIZE
b. Identify 3 structures that are found in both prokaryotic and eukaryotic cells.
Flagella, plasma membrane, cytoplasm, ribosomes, chromosomes, DNA.
2. Define what is an organelle?
Wrapped in their own membrane inside the membrane surrounding the entire cell.
Perform specific functions.
Give some examples.
Mitochondria, lysosomes, nucleus, golgi complex, etc.
Is a ribosome an organelle?
No, it does not have its own membrane.
3. For the 3 main parts of a cell:
a. Identify the name of the structure that wraps around the cell.
1.) Plasma membrane
2.) Nucleus
3.) Cytoplasm
b. Identify the fluid that fills the inside of the cell, and the 2 components in the fluid:
Cytoplasm - 1.) Cytosol, 2.) organelles.
1
,c. Describe the composition of the cytosol:
Water and dissolved components.
i. What is the percent of water?
75-90%
4. Identify the general functions of the cytoskeleton protein filaments.
Cell support and shape.
Organization of chemical reactions.
Movement of molecules in cells.
5. For cytoskeleton microfilaments:
a. Identify an example of microfilament proteins and types of cells where they are found.
Composed of actin and myosin.
b. What is the function of the microfilament proteins for your example?
Involved in muscle contraction.
6. Identify a function of intermediate cytoskeleton filaments.
Glues cells together.
7. For microtubules:
a. Identify 3 movement structures composed of microtubules and examples of cells
where they are found.
1.) Spindles
2.) Cilia
3.) Flagella
Found in sperm.
b. Identify the microtubules that are formed by the centrioles and the purpose.
Centrosomes - Formation sight for mitotic spindles during cell division.
2
, 8. For ribosomes:
a. Describe the composition of the structure.
2 subunits - rRNA and protein
b. Identify the function of ribosomes.
Site for protein synthesis; connects amino acids using instructions from DNA genes.
c. Which monomers are connected by ribosomes?
Amino acids
d. Where do the instructions come from for this function?
DNA genes
e. Where are 2 places in the cell where ribosomes are found?
Inside cytoplasm (free ribosomes) and attached to endoplasmic reticulum (bound
ribosomes).
f. How many ribosomes are found in human cells?
1000’s
9. For endoplasmic reticulum (ER):
a. Where in the cell is ER found?
Surrounding the nucleus.
b. What is attached to some types of ER?
Ribosomes
c. What is the function of rough ER?
Modifies molecules and connects proteins with other molecules.
d. What is the function of smooth ER?
Detoxifies harmful substances like drugs and synthesizes steroids and fatty acids.
3
