BIOS 242 Week 2 Active Learning Template: Cells

Student Name

Chamberlain University

BIOS-242 Fundamentals of Microbiology

Prof. Name

Date

Active Learning Template: Cells

Draw an image of a Prokaryotic Cell

Question: Draw an image of a Prokaryotic cell in the space below. Label all the organelles and structures present in a typical prokaryotic cell.
Answer: A prokaryotic cell consists of several essential structures that allow it to function and survive. These include:

Fimbriae: Hair-like projections that enable the cell to attach to surfaces and other cells.
Ribosome: Small structures responsible for protein synthesis.
Nucleoid: The region where the genetic material (DNA) is located, since prokaryotes lack a true nucleus.
Flagellum: A whip-like structure that facilitates mobility.
Cell Wall: Provides structural support and protection to the cell.
Plasma Membrane: Controls the entry and exit of substances in and out of the cell.

Organelles and Structures in Prokaryotic Cells

Question: Complete the following table by listing various organelles and structures commonly found in a prokaryotic cell and describe their functions in 1–2 sentences.

Answer:

Organelle/Structure	Function
Fimbriae	Allow bacterial cells to adhere to surfaces or other cells, aiding in colonization and infection.
Ribosome	Facilitate protein synthesis by translating genetic information from RNA.
Nucleoid	Houses the genetic material (DNA) in a single circular chromosome.
Flagellum	Provides motility, allowing the cell to move toward nutrients or away from harmful environments.
Cell Wall	Maintains cell shape, prevents lysis, and protects against external stress.
Plasma Membrane	Regulates transport of molecules in and out of the cell, maintaining homeostasis.
Cytoplasm	A gel-like substance that contains enzymes, ions, and molecules essential for metabolic processes.
Capsule (when present)	Protects the cell from immune responses and desiccation, enhancing survival.
Plasmid	Small DNA molecules carrying additional genes, often linked to antibiotic resistance.

Prokaryotic and Eukaryotic Cells

Cells are the fundamental units of life. They exist in two main forms: prokaryotic and eukaryotic. Prokaryotic cells are generally smaller, less complex, and lack membrane-bound organelles, whereas eukaryotic cells are larger, structurally complex, and contain specialized organelles enclosed by membranes.

In a typical prokaryotic cell, each structure contributes to survival. For example, the capsule offers protection against phagocytosis, while the cell wall provides rigidity. Structures like pili allow attachment to surfaces, whereas flagella assist in mobility. Genetic material is located in the nucleoid, while plasmids offer additional traits, such as antibiotic resistance. Ribosomes play a crucial role in protein synthesis, and the plasma membrane manages material exchange.

By contrast, eukaryotic cells possess highly specialized organelles. The nucleus safeguards DNA and coordinates activities such as growth and reproduction. The mitochondria function as the powerhouses of the cell, generating ATP through cellular respiration. In plant cells, chloroplasts capture sunlight for photosynthesis. Vacuoles provide storage for nutrients and waste, while lysosomes contain enzymes for the breakdown of biomolecules. Together, these organelles allow eukaryotic cells to perform complex functions that support multicellular life.

Similarities Between Prokaryotic and Eukaryotic Cells

Similarities
Both types of cells carry out essential life functions.
Both contain DNA as their genetic material.
Both have ribosomes for protein synthesis.
Both may exist as unicellular organisms (e.g., bacteria, yeast, amoeba).
Both contain vacuoles for storage of water, nutrients, or waste.

Differences Between Prokaryotic and Eukaryotic Cells

Feature	Prokaryotic Cells	Eukaryotic Cells
Nucleus	Absent; DNA found in nucleoid	Present; enclosed within a nuclear membrane
Membrane-bound organelles	Absent	Present (e.g., mitochondria, chloroplasts, lysosomes)
DNA Structure	Single circular DNA molecule	Multiple linear chromosomes
Size	Smaller (1–10 µm)	Larger (10–100 µm)
Complexity	Relatively simple	Highly complex
Mitochondria	Absent	Present

References

Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K., & Walter, P. (2015). Molecular biology of the cell (6th ed.). Garland Science.

BIOS 242 Week 2 Active Learning Template: Cells

Madigan, M. T., Bender, K. S., Buckley, D. H., Sattley, W. M., & Stahl, D. A. (2018). Brock biology of microorganisms (15th ed.). Pearson.