Exam 1 Learning Objectives Flashcards
Macro
A nutrient that an organism needs in larger quantity. 6 Macros Carbon, Nitrogen, Phosphorus, Hydrogen, Oxygen and Sulfur make up the carbs, lipids, nucleic acids, and proteins of the cell.
Micro Nutrients
A nutrient that an organism needs in smaller quantity, typically a vitamin or a mineral. *Cobalt, Manganese, Molybdenum, Nickle, Zinc, and ambitious trace contaminants on glassware and in water. **Not added to media in labs, sufficient amount already present.
Cofactors
A metallic ion or a coenzyme required by an enzyme to perform normal catalysis such as Cobalt needed for B12.
What are the different types of microbial metabolism?
Heterotrophy Autotroph Phototroph Chemolithotroph Organotroph
Heterotrophy
those catabolizing reduced organic molecules (proteins, carbohydrates, amino acids, and fatty acids)
Autotroph
The metabolic reduction of carbon dioxide to produce organic carbon for biosynthesis.
Organotroph
The metabolic oxidation of organic compounds to yield energy without light absorption.
An organotroph is an organism that obtains hydrogen or electrons from organic substrates. i.e., animals and bacteria
Phototroph
The fixation of single-carbon compounds into organic biomass, using light as an energy source.
An organism that manufactures its own food from inorganic substances using light for energy. Green plants, certain algae, and photosynthetic bacteria are phototrophs.
Chemolithotroph
Metabolism in which single-carbon compounds are fixed into organic biomass, using energy from chemical reactions without light absorption.
**Organic compounds contain a carbon molecule and usually a hydrogen molecule, whereas inorganic compounds contain neither of those.
An organism that is able to use inorganic reduced compounds as a source of energy
Biosynthesis
The production of complex molecules within living organisms or cells… basically takes things and turns them into macros. Biosynthesis is essential because the products it produces are essential for life.
Membrane Potential
Is a potential gradient that forces ions to passively move in one direction
compares whats inside to whats outside
Proton Motive Force
The inwardly directed proton gradient is called proton motive force.
Is the force that promotes movement of protons across membranes downhill the electrochemical potential.
ATP Synthase
A protein complex that synthesizes ATP from ADP and inorganic phosphate using energy derived from the transmembrane proton potential. It is located in the prokaryotic cell membrane and in the mitochondrial inner membrane.
Nutrient Uptake
In order to support its’ activities, a cell must bring in nutrients from the external environment across the cell membrane. In bacteria and archaea, several different transport mechanisms exist.
Coupled Transport:
The movement of a substance against its electrochemical gradient using the energy provided by the simultaneous movement of a different chemical down its electrochemical gradient.
ABC Transport:
An ATP-powered transport system that contains an ATP binding cassette.
Siderophores:
Are secreted to bind ferric iron and transport it into the cell, where it is reduced to the more useful ferrous form. Siderophore-iron complexes enter cells with the help of ABC transporters.
Binary Fission
The process of replication in which one cell divides to form two genetically equivalent daughter cells of equal size.
Doubling Time:
The generation time of bacteria in culture. The amount of time it takes for the population to double.
Generation Time:
The species-specific time period for doubling of a population in a given environment, assuming no depletion of resources.
What are the bacterial growth curve phases?
- -Lag Phase
- -Log Phase
- -Stationary Phase
- -Death Phase
Lag Phase
“Prep” they are not growing yet but they are ensuring they have the nutrients they need, making enzymes and repairing any damage. *preparing cell machinery for growth.
Log Phase
Growth approximates an exponential curve
Stationary Phase:
: #dividing cells = #dying cells –> cells stop growing and shut down their growth machinery while turning on stress responses to retain viability. They are making too much waste, and the environment is getting toxic.
Death Phase
Dying cells are more than dividing cells, cells die with a “half-life” similar to that of radioactive decay, a negative exponential curve.
Continuous Culture
Can be used to sustain a population of bacteria at a specified growth rate and cell density. (chemostat is the most common)
Heat-Shock Response
Produces a series of protective proteins in organisms exposed to temperatures near the upper edge of their growth range.
Water Activity
A measure of how much water in a solution is available for a microbe to use.
Osmolarity
The measure of the number of solute molecules in solution.
Halophile
An organism that requires a high extracellular sodium chloride concentration for optimal growth.
Reactive Oxygen Species (ROS)
A type of unstable molecule that can lead to cell death or damage
Which microbes can utilize oxygen for energy production?
- -Obligate Aerobes
- -Facultative Anaerobes
- -Microaerophiles
