Sinclair Community College | Bio 2205 Exam 3

What are the essential nutrients of a bacterial cell?

Carbon

Hydrogen

Oxygen

Nitrogen

Phosphorus

Sulfur

Sodium

Iron

Calcium

Magnesium

Zinc

What are the differences between macronutrients and micronutrients?

Macronutrients: A chemical substance required in large quantities. | Ex. Hydrogen, Carbon, & Oxygen

Micronutrients: A chemical substance required in small quantities. | Ex. Manganese, Zinc, & Nickel.

What terms describe an organism's sources of carbon and energy?

Energy Sources: Phototrophs, Chemotrophs,

Carbon Sources: Autotrophs , Heterotrophs

Combinations of Energy and Carbon Sources: Photoautotrophs, Chemoautotrophs, chemoorganic autotrophs, chemolithoautotrophic, heterotroph, photoheterotroph, chemoheterotroph,

Other: saprobe, parasite

Define Saprobe

An organism that feeds on dead organisms

Define parasite

An organism which lives on and feeds on another organism and causes it harm

What is diffusion?

The movement of particles from an area of high concentration to an area of low concentration.

What is osmosis and how does it work?

A type of diffusion, It is when the concentration of water in a cell and outside of a cell is different (not equal). So, water moves to equalize the concentration. Osmosis works in the same way as diffusion, but within and outside of a cell. Osmosis occurs in both plant and animal cells.

What happens to a cell in isotonic conditions?

The solute concentration is balanced on both sides of the plasma membrane, and there is no net movement of water into or out of the cell.

What happens to a cell in hypotonic conditions?

A cell placed in this solution will swell and expand until it eventually bursts through a process called cytolysis

What happens to a cell is hypertonic conditions?

A cell placed in this solution will shrivel and die by a process known as plasmolysis.

What are the different types of active and passive transport ?

Passive Transport: Simple Diffusion & Facilitated Diffusion

Active Transport: Carrier-mediated Active Transport, Group Translocation, & Endocytosis

What are five types of bacteria based on their temperature prefences?

Psychrophiles, Psychrotrophs, Mesophiles, Thermophiles, Hyperthermophiles

Explain how different organisms deal with oxygen

Obligate Aerobes

Facultative Anaerobes

Microaerophiles

Aerotolerant Anaerobes

Strict Obligate Anaerobes

Name three other physical facts that microbes must contend with

Temperature

Oxygen

pH

Relative Humidity

Osmotic Pressure

Other Physical Facts: light intensity, radiation, and pressure.

List five types of associations microbes can have with their hosts

Mutualistic

Commensalistic

Pathogenic

Symbiotic

Dysbiosis

discuss characteristics of biofilms that differentiate them from planktonic bacteria

Different genes are utilized in the two situations. The same chemical cells secrete during quorum sensing are responsible for some gene expression changes.

Describe the major way that bacteria divide; name another way used by fewer bacteria

Binary Fission,

Budding

Define doubling time and how it relates to exponential growth

Time required for a complete binary fission cycle from parent cell to two new daughter cells. also called generation time.

identify three methods besides a growth curve to count bacteria.

Turbidity

Direct Cell Count

Automated Devices; coulter counter, flow cytometer

What are the four phases of a growth curve in a bacterial culture?

Lag Phase

Exponential Growth Phase - Log Phase

Stationary Phase

Death Phase

What happens during a bacterial culture's Lag Phase of a growth curve?

Newly inoculated cells adjust to their new environments and grow in size; they may also adhere to surfaces.

What happens during a bacterial culture's Exponential growth Phase of a growth curve?

Peak growth of the bacteria; food and space are plentiful so no limiting factors are affecting the growth; this is the best time to culture or make slides from the bacteria.

What happens during a bacterial culture's Stationary Phase of a growth curve?

Growth is slowed or stopped; nutrients have begun to be depleted and most space is already occupied; as some bacteria die as others replace them

What happens during a bacterial culture's death Phase of a growth curve?

Nutrients or other limiting factors have run out; the bacteria begin to die off at an exponential rate; can be extended by slowing the bacteria's metabolism (such as refrigeration).

Define Acidophillic

An organism whose optimal growth pH is 2.0 or lower.

Define Active Transport

Movement across cell membrane--from low to high concentration--requires energy

Define Aerobe

A microorganisms that lives and grows in the presence of free gaseous oxygen (O2)

Define Aerobic Respiration

Respiration in which the final electron acceptor in the electron transport chain in oxygen (O2). This type of respiration makes the most ATP per glucose molecule

Define aerotolerant anaerobes

Can tolerate air , but usually does NOT want oxygen

Define Anaerobe

A microorganism that grows best, or exclusively, in the absence of oxygen

Define anatagonism

A relationship in which microorganisms compete for survival in a common environment by taking actions that inhibit or destroy another organisms

Define Autotroph

A microorganism that requires only inorganic nutrients and whose sole source of carbon is atmospheric carbon dioxide.

Define Barophile

A microogranism that thrives under high (usually hydrostatic) pressure

Define Binary Fission

The formation of two new bacterial cells of approximately equal size as the result of parent cell division.

Define Chemoautotroph

Organism that makes organic carbon molecules from carbon dioxide using energy from chemical reactions

Define Chemotroph

Organism that oxidizes compounds to feed on nutrients

Define Coevolution

A biological process whereby a change in the genetic composition in one organism leads to a chagne in the genetics of another organism.

Define Commensalism

An unequal symbiotic relationship in which one species derives benefit without harming the other.

Define Death phase

Cell growth ends due to a lack of nutrition, environmental depletion, and waste accumulation. Populations of cells begin to die.

Define Direct (total) cell count

Counting total number of individual cells being viewed with magnification. Counting isolated colonies of organisms growing on a plate of media as a way to determine population size.

Define Endocytosis

The process whereby solid and liquid materials are taken into the cell through membrane invagination and engulfment into a vesicle.

Define Essential Nutrient

Any ingredient such as a certain amino acid, fatty acid, or vitamin, or mineral that cannot be formed by an organisms and must be supplied in the diet. A growth Factor

Define Extremophiles

Organisms capable of living in harsh enviornments, such as extreme heat or cold

Define Facilitated Diffusion

The passive movement of a substance accross a plasma membrane from an area of higher concentration to an area of lower concentration utilizing specialized carrier protients. No ATP is required for this process.

Define Facultative Anaerobe

Does not require oxygen for its metabolism and is capable of growth in the absence of it.

Define Generation Time

Time required for a complete fission cycle from parent cel lto two new daughter cells. Also called doubling time.

Define Growth Curve

A graphical representation of the change in population size overtime. This graph has four periods known as lag phase, exponential or log phase, stationary phase, and death phase

Define Halophile

A microbe whose growth is either stimulated by salt or requires a high concentration of salt for growth

Define Hetertroph

An organism that relies upon consuming organic compounds for its carbon and energy needs

Define Hyperthermophile

An organism whose optimal growth temperature is above 800c (1760F), with a temperature range from 600c to 1130c

Define Hypertonic

Having a greater osmotic pressure than a reference solution.

Define Hypotonic

Having a lower osmotic pressure that a reference solution

Define Isotonic

Two solutions having the same osmotic pressure such that, when separated by a semipermeable membrane, there is not net movement of solvent in either direction.

Define Macronutrients

A chemical substance required in large quantities (phosphate, for example)

Define Maximum Temperature

The highest Temperature at which an organisms will grow

Define Mesophile

Microorganisms that grow at intermediate temperatures

Define Methanogens

Methane Producers

Define Microaerophile

an anerobic bacterium that requires oxygen at a concentration less than that in the atmosphere

Define Micronutrients

A chemical substance required in small quantities ( trace metals, for example)

Define Minimum Temperatrue

The lowest temperature at which an organisms will grow

Define Mutualism

A symbiotic relationship in which organism live in an obligatory but mutually beneficial relationship.

Define Normal Microbiota

The native microbial forms than at individual harbors

Define Nutrition

The acquisition of chemcial substances by a cell or organism for use as an energy source or as building blocks of cellular structures

Define obligate

without alternative; restricted to a particular characteristic

Define optimum temperature

the temperature at which a species shows the most rapid growth rate

Define Osmophile

A microogramism that thrives in a medium having high osmotic pressure

Define Parasites

an organism that lives on or within another organism (the host), from which it obtains nutrients and enjoys protection. It produces some degree of harm in the host.

Define Parasitism

A symbiotic relationship between two organisms in which the colonizer benefits and the other is harmed

Define Pathogen

Any agent (usually a virus, bacterium, fungus, protozoan, or helminth) that causes disease

Define pH

A system for rating acidity and alkalinity that looks at the hydrogen ion concentraion

Define Phagocytosis

A type of endocytosis in which the cell membrane actively engulfs large particles or cells into vesicles

Define photoautotrophs

an organism that uses light for its energy and carbon dioxide chiefly for its carbon needs.

Define phototrophs

microbes that use photosynthesis to feed

Define pinocytosis

the engulfment or endocytosis, of liquids by extensions of the cell membrane

define psychrophile

microorganism that thrives at low temperatures (00c - 200c), with a temperature optimum of 00c - 150c

Define quorum sensing

the ability of bacteria to regulate their gene expression in response to sensing bacterial density

define satalitism

a commensal interaction between two microbes in which one can grow in the vicinity of the other due to nutrients or protective factors release by the substrate

Define saturation

the complete occupation of the active site of a carrier protein or enzyme by the substatrate, no more substrate can be handled by the enzyme.

define symbiosis

an intimate association between individuals from two species can benefit both individuals, help one and harm the other or help one and not effect the other

define termophile

a microorganism that thrives at a temperature of 500c or higher

Define trace elements

micronutrients (zinc, nickel, and manganese) that occur in small amounts and are involved in enzyme function and maintenance of protein strucutre.

Define Obligate Aerobes

require oxygen for aerobic respiration. they have enzymes that neutralize toxic forms of oxygen.

Define Strict Obligate Anaerobes

Can't use oxygen and can't grow or survive in its presence, oxygen can poisent them.

Define Dysbiosis

Imbalance in bacterial composition, changes in bacterial metabolic activities, or changes in bacterial distribution within the gut.

Define Turbidity

cloudiness of a solution, usually due to suspended particles

What does the root word -litho mean?

stone

what does the root word troph- mean

food

what does the root word -phile mean

love

what does the root word -obe mean

to live

what does the root word hetero- mean

other

what does the root word auto- mean

self

what does the root word photo- mean

light

what does the root word chemo- mean

chemical

what does the root word sapro- mean

rotten

what does the root word halo- mean

salt

what does the root word thermo- mean

heat

what does the root word psychro- mean

cold

what does the root word aero- mean

air

what does the root word -tonic mean

tension

what does the root word iso- mean

same