Micro Exam 1

Cell

Cell

a dynamic entity that forms the fundamental unit of life

Genome

A cell's full complement of genes

plasmids

help prokaryotes thrive in their environment

housekeeping genes

genes that are essential for the survival of a cell and are found on the proper chromosome

evolution

the process of change over time that results in new varieties and species of organism

phylogeny

evolutionary relationships between organisms

microbial communities

populations of microorganisms that exist in nature as interacting assemblages

ecosystem

all living organisms plus physical and chemical constituents of their environment

Robert Hooke

looked at the fruiting structures of molds

Antoni van Leeuwenhoek

Father of Microbiology

Ferdinand Cohn

discovered bacterial endospores

Louis Pasteur

disproved theory of spontaneous generation; beef broth experiment

Robert Koch

Father of infectious diseases (Koch's postulates)

applied research

research that was designed from the ground up, to solve a certain problem

basic research

research that is done just to answer basic questions, with no specific problem to solve

microbial systematics

the science of grouping and classifying microorganisms

microbial physiology

study of the nutrients that microbes require for metabolism and growth, and the products that microorganisms generate

cytoplasmic membrane

thin structure that surrounds the cell and its required in order to be a microorganism

integral proteins

one that spans the entire width of the membrane

peripheral proteins

one that is only on one side of the membrane and only spans about half of the membrane

simple transport

driven by the energy of the proton motive force, where H+ ions push the substance through the channel

group translocation

chemical modification of the transported substance driven by a protein that helps to push the molecule through the channel in the membrane

ABC transporter

periplasmic binding proteins are involved and energy comes from ATP

porins

pores that allow for diffusion to occur

gram negative cell

• One thin cell wall

• Pinkish orange stain

• 2 bilayers

gram positive cell

• -One thick cell wall

• Purple stain

• One bilayer

peptidoglycan

rigid layer that provides strength to the cell wall

teichoic acids

acidic substances that are only found embedded in the cell wall of the gram positive cells

periplasm

space located between the cytoplasmic and outer membrane

pseudomurein

polysaccharide that mimics peptidoglycan that is found in archaeal cell walls

s-layers

most common cell wall type in archaea and is arranged in a paracrystalline structure

capsules and slime layers

adhesion factors; formation of biofilms--can eventually become mineralized

fimbrae and pili

involved in adhesion, bacteria to bind together or to other surfaces

inclusions

energy stores

gas vesicles

aquatic bacteria can use these to position themselves in water

endospores

some bacteria produce these to help them survive very adverse conditions

flagella

extension for transport

survival spores

1:1 ratio where the parent cell dies and the spore becomes the new cell

replication spores

goal is to increase numbers of exact copies of the parent cell

taxis

directed movement in response to chemical or physical gradients

nutrients

supply of monomers required by cells for growth

growth factors

organic compounds required in small amounts by certain organisms

defined media

precise chemical composition is known

complex media

composed of digest of chemically undefined substances

enriched media

contain complex media but also excess nutrients for a certain microbe

selective media

contains compounds that selectively inhibit growth of some microbes but not others

differential media

contain an indicator that detects a chemical reaction that occurs during growth

pure cuture

culture containing only a single kind of microbe

contaminants

unwanted organisms in a culture

metabolism

the sum total of all of the chemical reactions that occur in a cell

catabolism

energy-releasing metabolic reactions

activation energy

energy required to bring all molecules in a chemical reaction into the reactive state

catalyst

substance that lowers the activation energy of a reaction

enzymes

biological catalysts; typically proteins; highly specific

active site

region of an enzyme that binds substrate

prosthetic groups

tightly bind to enzymes

coenzymes

loosely bound to enzymes

cofactors

help to shape the active site of enzymes

glycolysis

the breakdown of glucose into 2 pyruvates; ATP, NADH release

fermentation

substrate level phosphorylation, ATP is directly synthesized from an energy-rich intermediate

respiration

oxidation phosphorylation, ATP is produced from proton motive force formed by the transport of electrons

aerobic respiration

oxidation using O2 as the terminal electron acceptor

electron transport systems

move electrons in a series from one molecule to another

ATP synthase

complex that converts proton motive force into ATP

F1

multiprotein extramembrane complex, faces the cytoplasm

F0

proton-conducting intramembrane channel

citric acid cycle

pathway through which pyruvate is completely oxidized to CO2

ADPG

precursor for glycogen biosynthesis

UDPG

precursor of some glucose derivatives needed for biosynthesis of important polysaccharides

gluconeogenesis

synthesis of glucose from phosphoenolpyruvate

phytanyl chains

mimic fatty acid chains and can either be a bilayer or monolayer

growth

increase in the number of cells

binary fission

cell division following enlargement of a cell to twice its minimum size

Fts

essential for cell division in ALL prokaryotes and interact to form the divisome

FtsZ

forms ring around the center of the cell

ZipA

anchor that connects FtsZ ring to cytoplasmic membrane

FtsA

helps connect the FtsZ ring to the membrane and also recruits other divisome proteins

bactoprenol

carrier molecule that serves as an anchor for peptidoglycan synthesis

glycolases

enzymes that interact with bactoprenol, catalyze glycosidic bond formation, cut the backbone of the carbon chain and insert a new subunit

transpeptidation

final step in cell wall synthesis

batch culture

a closed system where nothing is added or taken out during the incubation period

optical density

how cloudy a culture is; can tell how dense a culture is with cells

Lag phase

no cell growth or binary fission; adjustment period to new media

Log phase

no limiting nutrients, maximum growth

Stationary phase

decrease in nutrients (limiting nutrient) no growth

death

linear decrease in number or live cells

continuous culture

an open-system where known amount of culture is taken out and the same amount of new broth is added

chemostat

most common type of continuous culture device, allows you to lock a culture into a single growth phase

microscopic counts

microscopic counts are done by grid plate and counted under microscope

viable cell counts

measurement of the colonies on a plate, which counts the living reproducing population

turbidity measurements

indirect, rapid and useful methods of measuring microbial growth

cardinal temperatures

the minimum, optimum, and maximum temperatures at which an organism grows

psychrophile

microorganism that prefers low temperatures for growth

mesophile

microorganism that prefers midrange temperatures for growth

thermophile

microorganism that prefers high temperatures for growth

hyperthermophile

microorganism that prefers very high temperatures for growth

neutrophiles

microorganisms that grow best at a pH between 6 and 8

acidophiles

microorganisms that grow best at low pH (<6)

alkaliphiles

microorganisms that grow best at high pH (>9)

minimum inhibitory concentration (MIC)

smallest amount of an agent needed to inhibit growth of a microorganism