Chapter 7 - Microbial Nutrition, Ecology, and Growth Flashcards
What are nutrients?
Nutrients are acquired from the environment and used for cellular activities
What is a substance called, whether in elemental or molecular form, that must be provided to an organism?
Essential nutrient
_____________ are required in relatively large quantities, and play a principal role in ____ ________ and ____________.
Macronutrients
cell structure
Metabolism
What is another name fro trace elements?
Micronutrients
___________ are present in smaller amounts, involved in _______ function and maintenance of ______ ________.
Micronutrients
enzyme
protein structure
What is an atom or simple molecule that contains a combination of atoms other than carbon and hydrogen called?
Inorganic nutrients
What is the name of a nutrient that contains carbon and hydrogen atoms, that is usually the product of living things?
Organic Nutrients
Examples of Principal Inorganic Reservoir of Elements.
Manganese, molybdenum, cobalt, nickel, zinc, copper, other trace elements— various geologic sediments
What is a Heterotrophs?
An organism that must obtain its carbon in organic form
What is formed by aerobic respiration and dependent on other life forms?
Heterotroph
_________ are carbon sources that exist in a form simple enough for ________, larger molecules must be ________ by the cell before absorption.
Heterotrophs
absorption
digested
What is called a “Self-feeder”, is an organism that uses inorganic CO2 as its carbon source, has the capacity to convert CO2 into carbon compounds, and is not nutritional dependent on other living things?
Autotroph
What is a phototroph?
Microbes that photosynthesize
What are microbes that gain energy from chemical compounds called?
Chemotroph
What captures energy from light rays and transform it into chemical energy that can be used for cell metabolism?
Photoautotrophs
Photoautotrophs produce what that can be used by themselves and heterotrophs?
Organic molecules
What uses organic compounds for energy and inorganic compounds as a carbon source?
Chemoautotrophs
What is lithoautotrophs?
Require neither sunlight nor organic nutrients and rely totally on inorganic materials
How are methanogens formed?
Formed in anaerobic, hydrogen-containing microenvironments of soil, swamps, mud, or intestines of some animals
Chemoautotrophs that produce methane from hydrogen gas and carbon dioxide are called?
Methanogens
Methanogens can be used for ?
Fuel and plays a role as a greenhouse gas
What are a majority of heterotrophic microorganisms called?
Chemoheterotrophs
Chemoheterotrophs get energy how?
By oxidizing chemical compounds
Chemoheterotrophs derive both carbon and energy from what?
Organic compounds
What is complementary to photosynthesis, and Earth’s balance of energy and metabolic gases is dependent on this reaction?
Aerobic Respiration
Aerobic Respiration is what principal pathway in animals, protozoa, fungi, and aerobic bacteria for obtaining?
Principal Energy Yielding Pathway
What is a Decomposers of plant litter, animal matter, and dead microbes, and Important in recycling nutrients held in organic materials?
Saprobic Microorganisms
Most saprobes have what and cannot do what with food?
Rigid cell wall and cannot engulf large particles of food
Saprobic Microorganisms release ______ into the environment to _____ food into smaller particles that can be ____________ into the cell.
enzymes
digest
transported
What must be taken into the cell and what must be taken out?
Necessary nutrients in and waster materials out
What is too nonselective to screen the entrance or exit of molecules?
Cell wall
What is diffusion?
The movement of molecules in a gradient from an area of higher density or concentration to an area of lower density or concentration
Diffusion across a cell membrane is determined by the ___________ _________ and the _________ of the substance.
concentration gradient
permeability
What is Osmosis?
The movement of water across a selectively permeable membrane.
What does it mean when a membrane is selectively or differential permeable?
The membrane has passageways that allow the passage of water but not other dissolved molecules
What are the conditions called when the solute concentration in the external environment is equal to the cell’s internal environment, Diffusion of water proceeds at the same rate in both directions, and are generally the most stable environments for cells, already in an osmotic steady state with the cell?
Isotonic Conditions
Hypotonic conditions cause a cell without walls to _______ and can _____.
Swell
Burst
What kind of condition is present when Solute concentration of the external environment is lower than that of the cell’s internal environment?
Hypotonic Conditions
What is the most hypotonic environment and why?
Pure water is the most hypotonic environment because it has no dissolved solutes
What are Hypertonic Conditions?
Environment outside the cell has a slightly higher concentration of solutes than inside the cell.
What does it mean when the cell has High osmotic pressure?
High osmotic pressure forces water to diffuse out of the cell and Limits the growth of microbes
Hypertonic conditions are the principle behind using what to preserve food?
Concentrated salt and sugar solutions
What is it called when there is little stress on cells?
Isotonic Conditions
Where do bacteria and amoeba live?
Fresh water ponds or Hypotonic environments
How does a amoeba move excess water out of the cell?
Utilize a contractile vacuole that constantly moves excess water out of the cell; requires energy
In hypertonic environments Cells must ______ the loss of water to the environment or increase the _______ of their internal environment.
restrict
salinity
What is Facilitated diffusion?
It is a mediated transport.
What Utilizes a carrier protein that will bind a specific substance and where Binding changes the conformation of the carrier proteins so that the substance is moved across the membrane?
Facilitated diffusion
What does it mean when a carrier proteins exhibit specificity?
They bind and transport only one or a few types of molecules
What is Active Transport?
Transport of nutrients against the diffusion gradient or in the same direction as the natural gradient but at a rate faster than by diffusion alone