HES 032-Microbiology and Parasitology
College of Nursing
2022-2023
RAD Learning (AY:_________)
Group Leader: MASCARDO, ANNIKA SABRINA
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LAZAGA, LOUISE CARATOL
Group Members: _______________________________________
MAGSAYO, JILIAN TRICKSY SULA-SULA
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MAN-ON, ANGELA SWING
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MANGLE, SHANAIA NICOLE LOMA
_______________________________________
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ACTIVITY NO. 2: Bacterial Cell Structure and Function
LEARNING OBJECTIVE: At the end of the laboratory period, the student should be able to:
1. Illustrate and label the different structures of a bacterial cell.
2. Define and determine the functions of each structure of the bacterial cell.
3. Differentiate eukaryotic cell and prokaryotic cell.
DISCUSSION:
Cytology, the study of the structure and function of cells, has developed during the past 75
years with the aid of the electron microscope and sophisticated biochemical research. Among
clinically relevant organisms, bacteria are single-cell prokaryotic microorganisms. Fungi and
parasites are single-cell or multicellular eukaryotic organisms, as are plants and all higher
animals. Viruses are dependent on host cells for survival and therefore are not considered
cellular organisms but rather infectious agents or acellular microbes.
A notable characteristic of eukaryotic cells, such as those of parasites and fungi, is the presence
of membrane enclosed organelles that have specific cellular functions. Prokaryotes and
eukaryotes both contain nucleic acids, proteins, lipids, and carbohydrates. They use the same
kinds of chemical reactions to metabolize food, build proteins, and store energy. It is primarily
the structure of cell walls and membranes, and the absence of organelles (specialized cellular
structures that have specific functions), that distinguish prokaryotes from eukaryotes.
The structures of a prokaryotic cell consists of structures external to the cell wall, the cell wall,
and structures internal to the cell wall.
Compiled by: Claire Mae Caval, RMT
Microbiology and Parasitology – Instructor
Southwestern University PHINMA
References:
Engelkirk, P., & Engelkirk, J. (2015). Burton's Microbiology for the Health and Sciences. 10th ed., Philadelphia:
Lippincott Williams & Wilkins
Tille, P.M. (2014). Bailey & Scott’s Diagnostic Microbiology, 13th Edition. Amsterdam: Elsevier Mosby Inc.
Tortora G., F. B. (2016). Microbiology an Introduction, 12th Edition. United States of America: Pearson Education
OBSERVATIONS:
1. Illustrate and label the different structures of a bacterial cell.
Compiled by: Claire Mae Caval, RMT
Microbiology and Parasitology – Instructor
Southwestern University PHINMA
2. Define and determine the functions of each of the structure of a bacterial cell.
A. Structures external to the cell wall
1. Glycocalyx
a surface layer that covers the It enables certain bacteria to resist
cell membrane of many phagocytic engulfment by white blood cells
bacteria, epithelial cells or other in the body or protozoans in soil and water.
cells
2. Flagella
microscopic hair-like It enables movement and chemotaxis.
structures involved in the
locomotion of a cell.
3. Fimbrae and Pili
these are thin, protein tubes they have adhesion allowing bacteria to
originating from the cytoplasmic colonize environmental surfaces or cells
membrane of many bacteria. and resist flushing.
B. Cell Wall
a rigid, external layer that is It keeps the interior components of the
specifically designed to provide cell intact and safe from the external
structural support and rigidity. environment.
C. Plasma (Cytoplasmic) Membrane
the membrane found in all cells It provides protection for a cell. It also
that separates the interior of the transports nutrients into the cell and
cell from the outside also to transport toxic substances out
environment. of the cell.
Compiled by: Claire Mae Caval, RMT
Microbiology and Parasitology – Instructor
Southwestern University PHINMA
D. Structures internal to the cell wall
1. Nucleoid
an irregularly shaped space where It is essential for controlling the activity of the
the genetic material of the cell is cell and reproduction. It is where transcription
located. and replication of DNA take place.
2. Cytoplasm
the gelatinous liquid that fills the It provides a platform upon which other
inside of a cell. organelles can operate within the cell.
3. Ribosomes
an intercellular structure made of It decodes the message and the formation
both RNA and protein, and it is the of peptide bonds.
site of protein synthesis in the cell.
4. Inclusions- diverse intracellular non-living
substances (ergastic substances) that
are not bound by membranes.
a. Metachromatic granules It represents a storage form for inorganic
phosphate and energy.
b. Sulfur granules It uses hydrogen sulfide as an electron source.
c. Lipid Inclusions Development and progression of atherosclerosis,
for virus replication and recognition and as nutrient
source for intracellular pathogens.
d. Polysaccharide granules It is used to store energy in organisms.
5. Endospores
are seed-like formations produced It allows the bacterium to produce a dormant
within the bacteria. They are highly and highly resistant cell to preserve the cell's
resistant, designed to ensure genetic material in times of extreme stress.
survival and preserve the genetic
information under environmental
stress.
Compiled by: Claire Mae Caval, RMT
Microbiology and Parasitology – Instructor
Southwestern University PHINMA
STUDY GUIDE QUESTIONS:
1. Differentiate the structure of prokaryotic from eukaryotic cells (tabular form).
Prokaryote Eukaryote
Nucleus Absent Present
Membrane-bound organelles Absent Present
Cell structure Unicellular Mostly multicellular; some unicellular
Cell size Smaller (0.1-5 μm) Larger (10-100 μm)
Complexity Simpler More complex
DNA Form Circular Linear
Examples Bacteria, archaea Animals, plants, fungi, protists
2. Give the different arrangement of flagella and provide an example of each flagellar
arrangement. (Illustrate each flagellar arrangement).
Examples: Examples: Examples: Examples:
- Vibrio cholerae - Alcaligenes - Pseudomonas - Escherichia coli
- Caulobacter faecalis putida - Bacillus subtilis
crescentus - Aquaspirillum - Pseudomonas - S almonella
- Campylobacter serpens fluorescens enterica
- Campylobacter - Bartonella
jejuni bacilliformis
Compiled by: Claire Mae Caval, RMT
Microbiology and Parasitology – Instructor
Southwestern University PHINMA
