Micro Exam 2: Notes

macro

micro

required in relatively large amounts

components of CHO, lipids, proteins, nucleic acids

required in trace amounts, often adequately supplied in water

silicilic acid

enzyme activity

heat resistance

cofactor for enzymes and complexes with ATP

cofactor for enzymes and electron-carrying proteins

CO₂

preformed organic molecules

• 1. energy source
• 2. process of breaking down and using energy (electron source)

• use light as their energy source
• from oxidation of organic and inorganic compounds

• -use reduced inorganic compounds as electron source
• -use reduced organic compounds as electron source

• a. use light energy and CO₂ as carbon source
• b. eucaryotic

• a. purple-green bacteria
• b. common inhabitants of polluted lakes and streams
• c. use organic matter as electron donor and carbon source

• a. oxidizes reduced inotganic compounds; eg. Fe, N, S molecules
• b. chemical transformation of elements; eg. NH₄⁺to NO₃^- (N-cycle)

• O - 20%
• N - 78%

fix their own nitrogen (root microbes)

• 1. demonstrate great metabolic flexibility
• 2. Alter metabolic paths in response to environmental changes
• 3. nonsulfur bacteria

photoorganotrophic heterophytes under anaerobic conditions, but oxidize organic molecules and function chemolithotrophically at normal O₂ levels

• a. present in nucleic acids, phospholipids, nucleotides (ATP) and others
• b. direct OP uptake by transport proteins
• c. most use inorganic

• 1. needed in the synthsis of certain amino acids
• eg. cysteine & methionine
• 2. meets requirements by assimilatory sulfate reduction

• a. a phenomenon inn which molecules move from an area of high concentration to an area of low concentration because of random thermal agitation
• b. requires a large concentration gradient for significant levels of uptake
• c. limited only to a few small molecules (eg.: O₂, H₂O, CO₂, glycerol)

• a. a process that involves a carrier molecule (permease) to increase the rate of diffusion
• b. net effect is limited to movement from an area of higher concentration to an area of lower concentration
• - requires smaller concentration gradient than passive diffusion
• - generally more important in eucaryotes
• - rate plateus when carrier becomes saturated

• 1. process in which metabolic energy is used to move molecules to the cell's interior where solute concentration is already higher (against con. gradient)
• 2. incolces carrier proteins (permeases) with specificity for binding solutes transported

• a. saturable uptake rate (similar to facilitated diffusion)
• b. requires expenditure as metabolic energy
• c. concentrates molecules inside the cell even when the concentration inside is already higher

ATP-binding cassette transport (ABC transporters)

• type of active transport- linked transport of two substances in the same direction (inward or outward)
• eg. E. Coli permease- transports lactose & a proton inward

• a. linked transport of two substances in opposite directions
• eg. E. Coli Na⁺ transport system pumps Na⁺ outwards in response to inward movement of protons

• a. Fe ³⁺ and its derivatices are extremely insoluable, little free iron available
• b. Sidererophores (low MW) complex with very insoluble ferric ion, which is then transported into the cell
• c. secreted when little iron is available in medium

the breakdown of larger, more complex molecules into smaller, simpler ones during which energy is released, reapped, and made available for work

the synthesis of complex molecules from simpler ones during which energy is added as input

chemical work, transport work, nutrient work

synthesis of complex molecules

nutrient uptake, waste elimination, ion balance

internal and external movement

• a. major source of biological energy
• b. photoautotrophs and chemolithoautotrophs trap energy
• c. use some to produce organic molecules from CO₂

• a. total energy in the universe remains constant
• b. energy may be redustributed either within a system or between the system and its surroundings
• c. energy is measured in calories

the amount of heat energy needed to raise 1.0 gram of water from 14.5 to 15.5*C

physical and chemical processes proceed in such a manner that disorder of the universe increases to the max possible

disorder

endergonic

positive standard free energy

phosphate group transfer potential

ADP + P_i

• protein catalysts with great specificity
• a. a caralyst is a substance that increases the rate of a reaction without being permanently altered

0- 5.5

5.5- 8.0

8.5- 11.5

10 or higher

pH=-log [H⁺] = log (1/[H⁺])

the end product inhibits the pacemaker enzyme

• 1. fermentation
• 2. aerobic respiration
• 3. anaerobic respiration

organic energy source oxidized and degraded without the use of an exogenous electron acceptor

electron acceptor: endogenous organic electron acceptor

O₂ as the final electron acceptor

• molecule other than O₂ as the final electron acceptor
• electron acceptor: NO₃^-, SO₄^2-, CO₂, fumerate

Inroganic electron donor

O_2, SO₄^2-, NO₃^-

• - glycolysis
• - pentose phosphate pathway
• - Entner-Duodoroff pathway

• (Embden-meyerhof pathway)
• For each 3C produce 2 ATP
• 1. 6-C sugar; glucose is phosphorylated twice ---> fructose 1,6-biphosphate using 2 ATPs
• 2. 3-C sugar; fructose 1,6 biphosphate cleaves into two 3-C molecules, each processed to pyruvate
• Each 3-C yields: 2 ATPs (total of 4 ATPs, net gain of 2 ATPs per glucose)

• 1. produces a cariety of 3-, 4-, 5-, 6-, & 7-C sugar PO₄³
• 2. converts 3 G-6-PO₄ to 2 fructose-6-PO₄ & a glyceraldehyde 3-PO₄
• 3. Produces NADPH & source of electrons for biosynthesis
• 4. 4- & 5- skeletons can be used for synthesis of macromolecules (amino acids; nucleic acids)

• 1. most bacteria use the glycolytic and pentose pathways, but some substitute the E-D for glycolysis
• 2. produces ATP, NADPH, and NADH

• 1. an energy-yielding process in which an energy substrate is oxidized without an exogenous electron acceptor
• 2. regeneration of NAD⁺ used during oxidation of glyceraldehyde 3-PO₄ to 1,3-biphosphoglycerate

ethanol and CO₂

• a) homolactic fermentors reduce pyruvate to lactate
• b) heterolactic fermentors form sustantial amounts of products other than lactate

produces either mixed or butane diol

• 1. pyruvate can be degraded to CO₂ by the TCA cycle after first being converted to acetyl-CoA
• 2. The reaction is accomplished by loss of one carbon atom as CO₂
• 3. ATP is produced in substrate-level phosphorylation
• 4. 3 molecules of NADH and 1 of FADH₂ are produced

2 ATPs

2 to 38 ATPs

time required to double population

• 1. ability to adapt to adverse conditions
• 2. procaryotes present where life can exist
• a. extremophiles grow in harsh environmental conditions that kills most othe organisms

• 1. solutes and water activity
• 2. pH
• 3. temperature
• 4. O₂ levels
• 5. pressure
• 6. radiation

an increase in cellular constituents that may result in an increase in cell size, an increase in cell number, or both

Microbiologists forllow changes in total population numbers

• 1. period of apparent inactivity during which the cells are adapting to a new environment and preparing for reproductive growth
• 2. cells may be synthesizing new cell components

meaning of or related to life, are living factors. Plants, animals, fungi, protist and bacteria are all biotic or living factors

meaning not alive, are nonliving factors that affect living organisms. Environmental factors such habitat (pond, lake, ocean, desert, mountain) or weather such as temperature, cloud cover, rain, snow, hurricanes, etc. are abiotic factors

• 1. period during which the m.o.s are growing @ maximal rate possible given their genetic potential, nature of medium & conditions
• 2. population is most uniform in terms of chemical and physical properties @ this stage
• 3. balanced growth
• 4. microbe growth limited by low concentration of required nutrient
• 5. increase in yield results when the limiting nutrients is supplied - Law of Limiting Factor
• 6. growth rate increase with increasing nutrient concentration to point of diminishing returns

• 1. period in which number of viable microorganisms remains constant either because,
• a. metabolically active cells stopped reproducing
• b. reproductive rate = death rate

• a. nutrient limitation
• b. toxic waste accumulation (alcohol=13%
• c. cell density (space)

• 1. cells irreversible loss of ability to reproduce
• 2. period during which cells are dying at an exponential rate
• 3. available H₂O can be reduced by:
• -osmotic effect
• -matric effect

interaction with solutes

absorption to solids

amount of water available to microorganisms

A_w= V_p(solution)/ V_p of pure water

can grow in solutions of both high and low A_w

enviroment of low A_w (high osmotic pressure, due to salt concentration)