MICROBIOLOGY AND PARASITOLOGY
BSCI 106 | CHAPTER 6AND 7: MICROBIAL PHYSIOLOGY AND GENETICS
SECOND SEMESTER | 2023-2024 | PROF: ELIJAH JOY SULADAY, MSC
KRISTEL ANNE M. MUYUELA | BSN 1P
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KRISTEL ANNE M. MUYUELA, BSN 1PRISTEL ANNE M. MUYUELA
1
Introduction
Physiology is the study of the vital life processes of organisms.
Microbial physiology concerns the vital life processes of
microorganisms. Scientists can learn about human cells by
studying the nutritional needs of bacteria, their metabolic
pathways, and why they live, grow, multiply, or die under certain
conditions. Bacteria, fungi, and viruses are used extensively in
genetic studies because they produce generation after generation
so rapidly.
Microbial Nutritional Requirements
All living protoplasm contains six major chemical elements:
carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur
Combinations of these and other elements make up vital
macromolecules of life, including carbohydrates, lipids, proteins,
and nucleic acids.
Materials that organisms are unable to synthesize, but are
required for building macromolecules and sustaining life, are
termed essential nutrients (e.g., certain essential amino acids and
essential fatty acids).
Categorizing Microorganisms According To Their Energy And
Carbon Sources
Organism’s energy source:
>Phototrophs use light
>Chemotrophs use either inorganic or organic chemicals
a. Chemolithotrophs use inorganic chemicals
b. Chemoorganotrophs use organic chemicals
Organism’s carbon source:
>Autotrophs use carbon dioxide (CO2) as their sole source of
carbon.
>Heterotrophs use organic compounds other than CO2
Combine both energy and carbon source:
>Photoautotrophs use light (energy source) and CO2 (carbon
source)
>Photoheterotrophs use light (energy source) and organic
compounds other than CO2 (carbon source)
>Chemoautotrophs use chemicals (energy source) and CO2
(carbon source)
>Chemoheterotrophs use chemicals (energy source) and organic
compounds other than CO2 (carbon source)
Ecology is the study of the interactions between living
organisms and the world around them.
Ecosystem refers to the interactions between living organisms
and their nonliving environment.
Interrelationships among the different nutritional types are of
prime importance in the functioning of the ecosystem.
Example: Phototrophs, such as algae and plants, are the
producers of food and oxygen for chemoheterotrophs, such as
animals.
Metabolism refers to all of the chemical reactions that occur in
a cell. The chemical reactions are referred to as metabolic
reactions. Metabolic reactions are enhanced and regulated by
enzymes known as metabolic enzymes.
Biologic Catalysts
Enzymes are biologic catalysts; they are proteins that either
cause a particular chemical reaction to occur or accelerate it.
They are also specific, in that they catalyze only one particular
chemical reaction.
A particular enzyme can exert its effect on only one particular
substance, known as the substrate for that enzyme.
The unique three-dimensional shape of an enzyme enables it to
fit the combining site of the substrate like a key fits into a lock.
An enzyme does not become altered during the chemical
reaction it catalyzes. (They don’t last forever, however)
1.1 MICROBIAL PHYSIOLOGY
- Introduction
- Microbial Nutritional Requirements
- Categorizing Microorganisms According To Their
Energy And Carbon Sources
1.2 METABOLIC ENZYMES
- Biologic Catalysts
- Factors That Affect the Efficiency of Enzymes
1.3 METABOLISM
-Catabolism
-Anabolism
1.4 BACTERIAL GENETICS
-Mutations
-Ways in Which Bacteria Acquire New Genetic
Information
1.5 GENETIC ENGINEERING
1.6 GENE THERAPY
OUTLINE
1.1 MICROBIAL PHYSIOLOGY
1.2 METABOLIC ENZYMES
