microbio test 2

catabolic reactions

energy releasing metabolic reactions

heterotroph

an organism requiring organic compounds as a carbon source

chemical potential

Energy stored in the bonds between atoms

-food

first law of thermodynamics

Energy can be transferred and transformed, but it cannot be created or destroyed.

second law of thermodynamics

Every energy transfer or transformation increases the entropy of the universe.

exergonic

Chemical reactions that release energy

-hydrolysis reactions

endergonic reaction

A non-spontaneous chemical reaction in which free energy is absorbed from the surroundings.

-dehydration synthesis reactions

Hydrolysis

Breaking down complex molecules by the chemical addition of water

Glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

-occurs in the cytoplasm and splits glucose in half, producing 2 ATP per glucose

Fermentation

Process by which cells release energy in the absence of oxygen

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

Respiration

oxidative phosphorylation; ATP is reduced from proton motive force formed by transport of electrons

aerobic respiration

Respiration that requires oxygen

anerobic respiration

use of electron acceptors other than oxygen

-less energy released compared to aerobic respiration

-dependent on electron transport, generation of a proton motive force, and ATPase activity

chemolithotrophy

uses inorganic chemicals as electron donors

-typically aerobic

-begins with oxidation of inorganic electron donor

-uses electron transport chain and proton motive force

a-Ketoglutarate and oxaloacetate

Precursors of several amino acids; Its converted to phosphoenolpyruvate, a precursor of glucose

Succinyl-CoA

required for synthesis of cytochromes, chlorophyll, and other tetrapyrrole compounds

Acetyl-CoA

necessary for fatty acid biosynthesis

Glyoxylate cycle

a modification of the citric acid cycle in which isocitrate is cleaved to form succinate and glyoxylate during growth on two-carbon electron donors such as acetate

-key intermediate

oxaloacetate

a precursor of several amino acids; OAA also converted to phosphoenolpyruvate, a precursor of glucose

Gluconeogenesis

synthesis of glucose from phosphoenolpyruvate

ADPG

adenosine diphosphoglucose -is a substrate widely used as a glucose donor

UDPG

uridine diphosphoglucose -the key substrate in the synthesis of both suc and polysaccharides

Nutrients

supply of monomers (or precursors of) required by cells for growth

Macronutrients

Nutrients required in large amounts

Micronutrients

nutrients required in trace amounts

carbon

required by all cells

-major element in all classes of macromolecules

nitrogen

key element in proteins, nucleic acids and many more cell constituents

kinetoplastids

A protist, such as a trypanosome, that has a single large mitochondrion that houses an organized mass of DNA.

-causes African sleeping sickness

Euglenids

nonpathogenic and phototrophic

-contain chloroplasts, can exist as heterotroph

-can feed on bacteria by phagocytosis

-Euglena

Alveolates

characterized by presence of alveoli which are sacs underneath the cytoplasmic membrane

-members are ciliates, dinoflagellates, and apicomplexans

ciliates

A group of protozoans that move by waving tiny, hair-like organelles called cilia.

dinoflagellates

plant-like protist that causes red tide

-fish kills and human poisoning(PSP)

apicomplexans

A type of parasitic protozoan

-cause serious human disease

-non motile

stramenopiles

Clade of protists with "hairy" flagellum includes water molds, diatoms, and brown algae

-organisms: oomycetes, diatoms, golden algae, and brown algae

Oomycetes

water molds based on their filamentous growth and the presence of coenocytic hyphae

diatoms

single-celled organisms. found in salt and fresh water. producers. make up a large percent of phytoplankton. cell walls contain cellulose and silica (frigid and glasslike). used in silver polish, toothpaste, filter and insulation

golden algae

A biflagellated, photosynthetic protist named for its color, which results from its yellow and brown carotenoids.

-chrysophyta

brown algae

One of a group of marine, multicellular, autotrophic protists, the most common type of seaweed.

rizaria

distinguished from other protists by their threadlike pseudopodia

-chlorarachniophytes: phototrophicc amoeba-like organism that has a flagellum for dispersal

-foraminifer: form shell like structures called tests, white cliffs of dover

amoebozoa

use pseudopodia for movement and feeding

-gymnamoebas, entamoeba, and slime molds

gymnamoebas

free living, inhabit soil and aquatic environments

Entamoebas

parasites of vertebrates and invertebrates

Slime molds

plasmodial and cellular

plasmodial slime molds

a type of protist that has ameboid cells, flagellated cells, and a plasmodial feeding stage in its life cycle

-hemitichia, physarum

cellular slime molds

A type of protist that has unicellular amoeboid cells and a multicellular reproductive body in its life cycle

-myxamoeba amoeboid: when food is plentiful

-psuedoplasmodium: slug like mass of cells with slime trail

-sorocarp: eventually produces spore

-Dictyostelium discoideum

dehydration synthesis

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

hydrolysis reaction

A chemical reaction that breaks apart a larger molecule by adding a molecule of water

exergonic reaction

A spontaneous chemical reaction in which there is a net release of free energy.

endergonic

A chemical reaction that requires the input of energy in order to proceed.

activation energy

energy that is needed to get a reaction started

oxidation reduction reaction

any chemical change in which one species is oxidized (loses electrons) and another species is reduced (gains electrons); also called redox reaction

glycolisis

occurs in cytoplasm; converts one glucose into 2 pyruvic acids, makes 2 ATP and NADH

Embden-Meyerhof pathway

Humans use this metabolic pathway for glycolysis:

ethanol fermentation

a form of anaerobic respiration found in yeast and bacteria

-pyruvate -> acetaldehyde + Co2

-Acetaldehyde -> ethanol

- NADH -> NAD

lactic acid fermentation

A series of anaerobic chemical reactions using pyruvic acid that supplies energy when oxygen is scarce

-lactobacillus, streptococcus

- sour cream, yogurt, sauerkraut, pickles, kimchee

mixed acid fermentation

Produces acetate, formate, lactate, and succinate, as well as ethanol, H2, and CO2

-Escherichia coli

butanediol fermentation

Converts pyruvic acid from glycolysis to many of the acidic products seen in mixed acid fermentation, but to a lesser extent and neutral end products such as butanediol and ethanol

-Enterobacter aerogenes

Phosphoroclastic Reaction

clostridium

glyoxylate cycle

a modification of the citric acid cycle in which isocitrate is cleaved to form succinate and glyoxylate during growth on two-carbon electron donors such as acetate

eletron transport chain

series of proteins embedded in a membrane along which energized electrons are transported

nitrate to nitrogen gas

Facutative anaerobes

-pseudomonas, bacillus, moraxella

Sulfate to Hydrogen Sulfide

strict anaerobe

-desulfovibrio

fumarate to succinate

(TCA cycle)

-escherichia coli, proteus, enterococcus

carbon dioxide to methane

greenhouse gases

Fe+3 to Fe+2

anaerobic respiration

-an element

phototrophy

uses light as energy source

Photophosphorylation

light-mediated ATP synthesis

Photoautotrophs

use ATP for assimilation of CO2 for biosynthesis

Photoheterotrophs

use ATP for assimilation of organic carbon for biosynthesis

cellulose to glucose

Enzyme - cellulase

Organisms - Clostridium, Actinomyces

Starch to glucose

enzyme- amylase

organism: bacillus subtillis

lactose to glucose and galactose

Enzyme - b -galactosidase

Organism - Escherichia coli

triglycerides to glycerol and fatty acids

enzyme- lipase

organism: bacillus subtillis, staphylococcus aureus

-media: spirit blue agar

phospholipids to phosphorylcholine and fatty acids

enzyme -phospholipase

Organism: clostridium perfringens

(gas gangrene)

media: egg yolk agar

Fatty acids

beta oxidation

Co A, FAD, NAD conveted to Acetyl Co A, FADH, NADH

protein to amino acids

enzyme - protease

Organism: Serratia marcescen

amino acid metabolism

Dehydrogenase -

Synthetase -

Transaminase -

Synthase -

Dehydrogenase

An enzyme that catalyzes a chemical reaction during which one or more hydrogen atoms are removed from a molecule.

-NH3 -> NH2

synthetase

Enzyme that adds amino acids to tRNA -an enzyme that catalyzes the linking together of two molecules

-NH2 + NH3 -> NH2 -NH2

Transaminase

Catalyzes the transfer of an amino group from one molecule to another

-NH2 + Oxalacetate -> Aspartate NH2

synthase

An enzyme that catalyzes the synthesis of a substance without involving the breakage of high energy phosphate bond

-NH2- NH2 -> NH2

pentose phosphate pathway

A metabolic process that produces NADPH and ribose 5-phosphate for nucleotide synthesis.

Biosynthesis of sugars

intermediate products of glycolysis are converted to complex sugars at the expense of ATP

- ADPG and UDPG

Biosynthesis of Amino Acids

- Carbon skeletons from intermediates in glycolysis or citric acid cycle

- Amino group derived from inorganic nitrogen source (ex. NH3)

Biosynthesis of fatty acids

fatty acids made 2 carbon atoms at a time

- requires acyl carrier protein (ACP)

- requires NADPH

synthesis of pentose sugar

an alternative to glycolysis and generates NADPH and pentoses. Phosphogluconate pathway

- Pentose phosphate pathway

- Hexose monophosphate shunt

pyrimidine biosynthesis

is responsible for synthesizing uracil nucleotide from cytosine and thymine. orotic acid precursor

-activated ribose is added

-there is UMP intermediate

-Products are CTP and TMP

purine biosynthesis

the metabolic pathways to synthesize and break down purines that are present in many organisms. starts from amino acids, Co2 and formyl groups

-Formyl groups added with the help of folic acid

-inosinic acid (IMP) intermediate

-AMP and GMP are formed from IMP

inhibitors of nucleotide synthesis

Methotrexate, aminopterin

-inhibits tetrahydrofolate to TMP

6-mercaptopurine

-inhibits conversion of IMP to AMP

5-fluoropyrimidine

-blocks conversion on UMP to TMP

sulfonamides block folic acid synthesis

Phosphorus

synthesis of nucleic acids and phospholipids

-macronutrients

potassium

required by enzymes for activity

-macronutrients

magnesium

stabilizes ribosomes, membranes, and nucleic acids

calcium

helps stabilize cell walls in microbes

-plays key role in heat stability of endospores

sodium

required by some microbes

growth factors

organic compounds required in small amounts by certain organisms

ex: vitamins, amino acids, purines, pyrimidines

culture media

Nutrient solutions used to grow microbes in the laboratory

defined media

precise chemical composition is known

complex media

composed of digests of chemically undefined substances

selective media

suppress unwanted microbes and encourage desired microbes

differential media

allows growth of several types of microbes and displays visible differences among those microbes