Microbiology Chapter 7
A saprobe differs from a parasite In that
A saprobe derive nutrients from dead plants and animals , but a parasite drives nutrients from living plants and animals.
The movement of substance from lower to higher concentration across a semipermeable membrane via a specific protein carrier and cell expenditure of energy is called
Active transport
Which organism has a challenge to maintain cellular electrolyte and fluid balance in its environment
All of the above have problems in maintaining electrolyte and fluid balance within the cell
The methanogens , producers of methane gas , require environment that
Are anaerobic with hydrogen gas and CO2
Bacteria living in a freshwater stream that are transferred to ocean water would
Become dehydrated due to the loss of water
Growth factors
Cannot be synthesized by the organism
Facilitated diffusion is limited
Carrier proteins in the membrane
The movement of molecules from an area of high concentration to an area of lower concentration is called
Diffusion
You want experiment with microbial growth in various nutrients , so you inoculate a loopful of E. coli into a tube of honey. Which statement best describes what you expect to happen and why
E. coli does not grow because it has been dehydrated by honey.
Which of the following require the cell to use energy
Endocytosis
The movement of substance from higher to lower concentration across a semipermeable membrane via a specific protein carrier but without energy expenditure is called
Facilitated diffusion
An organism that grow slowly in the cold but has an optimum growth temperature of 32c is called an
Facultative psychrophile
Obligate saprobes can adapt to living host
False
Saprobes do not need a carbon source for growth and metabolism
False
Whether an organism is an autotroph or heterotroph depends on its source of nitrogen
False
The cell wall will help prevent the cell from bursting in conditions
Hypotonic
An important ion found in the cytochrome pigment of cellular respiration is
Iron
Microorganisms require large quantities of for use in cell structure and metabolism
Macronutrients
An important mineral ion that is a component of chlorophyll and serves as a stabilizer of membranes and ribosomes is
Magnesium
Most of the dry weight of a microbial cell is form
Organic compounds
Diffusion of water through a semipermeable membrane is called
Osmosis
When whole cells or large molecules in solution are engulfed by a cell this endocytosis specifically termed
Phagocytosis
This microbe is photosynthetic , but in the absence of light it can use organic compounds as an energy source. it carbon source is an organic compound. The appropriate classification for this organism would be
Photoautotroph
Mediated transport of polar molecules and one across the plasma membrane utilizes an carrier that binds to the substance and causes a conformational change to allow its movement across the membrane
Protein
Organisms that feed on dead organisms for nutrients are called
Saprobes
Calcium is required for bacteria because it
Stabilizes the cell wall
Many lake in the united states are suffering from periodic algae blooms , which can be thought of as an infection of the lake. although the algae are naturally-occurring in the lake . when adjacent farm fields are over-fertilized with diammonium phosphate. the run-off deposits these nutrients in lake , allowing the algae to grow without limit. which of the following statement is incorrect the overgrowth of algae?
The algae are heterotrophs
Microorganisms require small quantities of for enzyme function and maintenance of protein structure
Trace elements
Facilitated diffusion and active transport require a carrier protein to mediates the movement across the plasma membrane
True
Inorganic nitrogen must be converted to ammonia to be used by a cell
True
Lithoautotrophs use inorganic nutrients for carbon and energy sources
True
Phosphorus is one of the major elements needed in larger quantities by microorganisms
True
Whether an organism is a phototroph or a chemotroph depends on its source of energy
True
Contractile vacuoles are
Used to expel excess water from cells