Module 1: The Microbial World Flashcards
What are microorganisms?
Microscopic forms of life (organisms too small to see with the naked eye)
What ARENT microorganisms?
WHY?
Viruses
–> Because they technically aren’t living, they can’t be considered organisms
What organisms are considered microorganisms? (5)
1) Bacteria
2) Protozoa
3) Archaea
4) Fungi
5) Algae
What are microbes?
Refers to microorganisms AND viruses
What is microbiology?
The study of microbes
Ways in which microbes HELP humans: (6)
1) Food digestion
2) Protect from harmful microbial invaders
3) Used to advance understanding of molecular machinery (research models)
4) Provide nitrogen to plant roots (nitrogen fixing bacteria)
5) Carry out fermentation (Ex: yogurt/alcohol,etc.)
6) Medicine production (Ex: Insulin)
Ways in which microbes DONT help humans: (3)
1) Infectious diseases
2) Crop failure
3) Food rot
What are the characteristics of life?
1) Made up of cells
2) Capable of:
a) Growth
b) Reproduction
c) Metabolism
3) Contain Genetic Information (+ variation)
4) Respond to external stimuli and ADAPT to external environ.
5) Homeostasis
What is the working definition of life?
A set of characteristics specific to a self-organizing, self replicating, non-equilibrium system that preserves and reinforces its existence in a given environment
Growth
Increase in mass of biological material
Reproduction
Production of new copies of an organism
Metabolism
A controlled set of chemical reactions within cells that extract energy + nutrients from the environment and transform them into new biological materials
Homeostasis
Active regulation of internal environment to maintain relative constancy despite external changes
Homeostasis vs Equilibrium
Homeostasis = an active process
Equilibrium = a passive state of being
–> Homeostasis attempts to achieve an equilibrium state in different systems
Why is homeostasis a condition of life but equilibrium is not?
Equilibrium implies a static state where no net change occurs:
–> essentially, a living organism at equilibrium is considered “dead” as it cannot respond to environmental fluctuations
Whereas an organism in homeostasis is “alive” as it is constantly responding to the environment rather than existing in a static state
All cells are foundationally made up of…
Macromolecules
What are macromolecules?
Large, complex organic molecules made up of (polymerized) simple subunits
Dry Weight
Weight obtained after removing all water from something (like a cell)
Macromolecules account for _________% of cellular dry weight
> 90% of cellular dry weight
4 major macromolecules
1) Polypeptides (proteins)
2) Nucleic Acids
3) Polysaccharides
4) Lipids
Polypeptides
AKA proteins
–> Polymers of amino acids joined together by peptide bonds
(often fold into highly specific structures which determine their function)
Polypeptide Functions
1) Enzymes –> Catalysis of chemical reactions
2) Structural Support/Cell Motility –> Cytoskeleton
3) Material Movement –> Membrane protein channels and pumps
What % of cellular dry weight do polypeptides make up?
~50-55% of cellular dry weight
What is the most abundant macromolecule?
Proteins (~50-55%)