micro quiz 6

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

macronutrient

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

superoxide dismutase and catalase.

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, very slight growth out o

psychrophile

Organisms that feed on dead organisms for nutrients are called

saprobes

Aerobic respiration is an example of

chemoheterotrophy

A barophile would grow best in

deep oceans

What compound has the highest concentration in a cell?

H2O

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

hypotonic

The term chemoheterotroph refers to an organism that

gets energy by oxidizing chemical compounds.

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

mutualistic

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

aerobe

Human pathogens fall into the group

mesophiles

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

commensalism

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

oxygen

The term facultative refers to

the ability to exist in a wide range of conditions.

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

The production of antibiotics is a form of antagonism called

antibiosis

The movement of molecules from an area of high concentration to an area of lower concentration is called

diffusion

Which of the following require the cell to use ATP?

endocytosis

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

parasites

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 term photoheterotroph refers to an organism that

gets energy from sunlight.

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

facultative anaerobe.

A microaerophile

requires a small amount of oxygen but won't grow at normal atmospheric levels.

Archaea, as a group, are not pathogens. This is because

mammalian hosts do not meet their environmental requirements.

Facilitated diffusion is limited by

carrier proteins in the membrane

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

exponential (log) phase.

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

phagocytosis

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

generation time.

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

endocytosis.

The movement of substances from higher to lower concentration across a semipermeable membrane that must have a specific protein carrier but no energy expenditure is called

facilitated diffusion.

Most of the dry weight of a microbial cell is from

organic compounds

All of the following could find a location in or on body tissues suitable for growth except

psychrophiles.

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

stationary phase.

Nutrient absorption is mediated by the

cell membrane

Bacteria living in a freshwater stream that are moved to salty seawater would

shrivel

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

synergism.

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

iron