Microbiology Chapter 7

Microorganisms require large quantities of this nutrient for use in cell structure and metabolism

Macronutrient

Microorganisms require small quantities of this nutrient for enzyme function and maintenance of protein structure

Trace element

Most of the dry weight of a microbial cell is from

Organic Compound

Which of the following is not a major element of a microbial cell

Copper

An organic nutrient that cannot be synthesized by the organism and must be provided is called a/an

Growth factor

An important mineral ion of the cytochrome pigments of cellular respiration is

Iron

An important mineral ion that is a component of chloroplasts and stabilizer of membranes and ribosomes is

Magnesium

Autotroph organism

Uses CO2 for its carbon source

Heterotroph organism

Must obtain organic compounds for its carbon needs

Calcium is required for bacteria because

It stabilizes the cell wall

Growth factors

cannot be synthesized by the organism

An organism that uses CO2 for its carbon needs and sunlight for its energy needs would be called a/an

Photoautotroph

The term phototroph refers to an organism that

Gets energy from sunlight

The term chemotroph refers to an organism that

Gets energy by oxidizing chemical compounds

The methanogens, producers of methane gas, require environments that

Are anaerobic with hydrogen gas and CO2

Organisms that feed on dead organisms for nutrients are called

Saprobes

The type of photosynthesis that does not produce oxygen

Occurs in purple and green sulfur bacteria

Archea as a group are not pathogens. This is because

Mammalian hosts do not meet their environmental requirement

Aerobic respiration is an example of

Chemoheterotrophy

Microorganisms that live in severe habitats, such as very hot, acidic or salty environments, are called

Extremophiles

Organisms called _____ live on or in the body of a host and cause some degree of harm.

Pathogens

The term obligate refers to

Existing in a very narrow niche

The term facultative refers to

The ability to exist in a wide range of conditions

The use of energy by a cell to enclose a substance in its membrane by forming a vacuole and engulfing it is called

Endocytosis

Which of the following microorganisms would find hypotonic conditions most detrimental?

Protozoa

Which of the following require the cell to use ATP?

Endocytosis

Contractile vacuoles are

Used to expel excess water from cells

Nutrient absorption is mediated by the

Cell membrane

Halobacteria regulate osmotic pressure by

Absorbing salt from the environment

Facilitated diffusion is limited by

Carrier proteins in the membrane

When whole cells or large molecules in solution are engulfed by a cell, this endocytosis is specifically termed

Phagocytosis

Mediated transport of polar molecules and ions across the plasma membrane utilizes a _____ _____ that will bind to the substance effecting a conformational change that allows movement across the membrane.

Protein carrier

In _____ conditions, the cell wall will help prevent the cell from bursting.

Hypotonic

Cultures of a bacterial species were incubated on the shelf of a refrigerator, out on a lab bench top, on the shelf of a 37 C incubator and on the shelf of a 50 C incubator. After incubation, there was no growth at 37 C and 50 C, slight growth out on the bench top and abundant growth at refrigeration. What term could be used for this species

Psychrophile

Cultures of a bacterial species were incubated out on the incubator shelf, in an anaerobic jar and in a candle jar. After incubation there was moderate growth of cultures in the candle and anaerobic jars, but heavy growth of the culture on the incubator shelf. This species is a/an

Facultative anaerobe

A microorganism that has an optimum growth temperature of 37 C, but can survive short exposure to high temperatures is called a(n)

Thermoduric

An organism that grows slowly in the cold but has an optimum growth temperature of 32 C is called a(n)

Facultative psychophile

An organism with a temperature growth range of 45 C to 60 C would be called a(n)

Thermophile

Human pathogens fall into the group

Mesophile

A microorganism that does not have catalase or superoxide dismutase would find it difficult to live in an environment with

Oxygen

A microaerophile

Requires a small amount of oxygen but won’t grow at normal atmospheric levels

The toxic superoxide ion is converted to harmless oxygen by two enzymes

Superoxide dismutase and catalase

An organism that can use gaseous oxygen in metabolism and has the enzymes to process toxic oxygen products is a(n)

aerobe

An organism that can exist in both oxygen and oxygen-less environments is a(n)

Facultative anaerobe

An organism that cannot tolerate an oxygen environment is a(n)

Obligate anaerobe

What type of media is used to demonstrate oxygen requirements of microbes?

Thioglycollate

A halophile would grow best in

Salt lakes

A barophile would grow best in

Deep oceans

The E. coli that normally live in the human large intestines and produce vitamin K that the body uses would be best termed a _____ relationship.

Mutualistic

The production of antibiotics is a form of antagonism called

Antibiosis

When microbes live independently but cooperate and share nutrients, it is called

Synergism

When microbes in close nutritional relationship and one benefits but the other is not harmed, it is called

Commensalism

A change in one partner in a close relationship that leads to a change in the other partner is

Coevolution

The time interval from parent cell to two new daughter cells is called the

Generation time

The phase of the bacterial growth curve in which the rate of multiplication equals the rate of cell death is the

Stationary phase

The phase of the bacterial growth curve in which newly inoculated cells are adjusting to their new environment, metabolizing but not growing is the

Lag phase

The phase of the bacterial growth curve that shows the maximum rate of cell division is the

Log phase

In the viable plate count method, a measured sample of a culture is evenly spread across an agar surface and incubated. Each _____ represents one _____ from the sample.

Colony, cell

When it is important to count the number of cells, determine cell size and differentiate between dead and live cells a ___ is used.

flow cytometer

Phosphorus is one of the major elements needed in larger quantities by microorganisms.

TRUE

Most microorganisms on earth can only live and survive in habitats that are similar to human body conditions.

FALSE

Inorganic nitrogen must be converted to ammonia to be used by a cell.

TRUE

Whether an organism is an autotroph or heterotroph depends on its source of nitrogen.

FALSE

Whether an organism is a phototroph or a chemotroph depends on its source of energy.

TRUE

Obligate saprobes can adapt to a living host

FALSE

A saprobe with a cell wall will utilize extracellular digestion.

TRUE

Saprobes do not need a carbon source for growth and metabolism.

FALSE

Lithoautotrophs use inorganic nutrients for carbon and energy sources.

TRUE

Facilitated diffusion and active transport require a carrier protein to mediate the movement across the plasma membrane.

TRUE

In a commensal relationship, the commensal benefits but the cohabitant is neither harmed nor benefited.

TRUE

Anaerobes can be cultured in a CO2 environment.

TRUE

The majority of microbes live and grow in habitats between pH 7 and 9.

FALSE

Bacteria have an average generation time of 24 hours.

FALSE

The time that it takes for a freshly inoculated agar culture to develop visible colonies is principally governed by that species’ generation time.

TRUE

Transverse binary fission results in 4 daughter cells from 1 parent cell.

FALSE

After binary fission, daughter cells will differ genetically.

FALSE

A closed culture system is used to determine a population growth curve.

FALSE

The degree of turbidity in a broth culture correlates to the amount of cell growth.

TRUE

The direct cell count, using a cytometer, can calculate viable cell numbers from a sample.

FALSE

A Coulter counter can count viable cells as well as determine the size.

FALSE

Bacterial biofilms stimulate the immune system differently than planktonic bacteria

TRUE

Planktonic bacteria are more susceptible to antibiotics as compared to biofilm microorganisms.

TRUE