Chapter 5 Flashcards
microorganisms use nutrients from their environmnt to produce macromolecules and chemicals required for (3)
growth, survival and replication
what is catabolism
generation of ATP and reducing power (NADH) from nutrients. By- products catabolism may be used as precursors molecules for anabolism
what is anabolism
poduction of macromolecules from building block and energy (ATP). Reducing power is provided by NADH
3 products from catabolism where 2 can be used by anabolism
- lost heat
* can be used by anabolism: - useful forms of energy
- the many building blocks for biosynthesis
7 essentials nutrients and their % for all microorganisms
C 50% O 17% N 13% H 8,2% P 2,5% S 1,8% Se less than 0,01%
5 essential cations and anions for most microorganism
Na Cl Mg K Ca
what are the macromolecular composition of a cell + their % of dry weight (6)
- protein, 55%
- lipid, 9,1%
- polysaccharide, 5,0% (in peptidoglycan)
- lipopolysaccharide, 3,4% (on the surface of Gram-negative bacteria)
- DNA, 3,1%
- RNA, (20,5%)
difference between a defined and a complex culture medium
in defined, we exactly know the components and the quantity of each nutrients
in complex, we know approximatively, but not exactly sure of every quantity
why leuconostoc mesenteroides is a fastidious organism
because it has vey specific nutrient demands because they have a lot of things they can’t make by themeselves
what is activation energy
energy needed to put all molecules in a reactive state
what is a catalyst
substance that lowers the activation energy, it does not affect the free energy, affects the rate
redox couples always written so that ______ form on the left, _______ form on the right
oxidized
reduced
the chemical reaction of the couple reaction releases energy but the how much energy that is released depends on what
the difference in reduction potential between the donor and the acceptor (the bigger is the difference, the bigger the enrgy released will be)
complete name of NAD
nicotinamide adenine dinucleotide
5 energy-rich compund
ATP (adenosine triphosphate) Aceytl CoA glucose 6-phosphate phosphoenolpyruvate acetyl phosphate
what are the three basic catabolic pathways that are required in most organisms to produce all of the precursors (carbon compounds and energy) needed for anabolism
- glycolytic pathway (glycolysis, Embden-Meyerhof pathway)
- pentose phosphate pathway (hexose monophosphate pathway)
- tricarboxylic acid pathway (TCA, citric acid circle, Krebs cycle)
2 possibilities for ATP synthesis
- fermentation: organic compunds are electron acceptor and electron donors. ATP is produced by substrate-level phosphorylation
- respiration: organic compunds are oxidized to CO2 with O2 (or substitue) as the electron acceptor. most of the ATP is produced by oxydative phosphorylation.
3 stages of glycolysis
- use energy (ATP) to create high energy molecules
- take advatange of the high energy molecules to create ATP
* * net yield of 2 ATP , 2 NADH + H+ and 2 pyruvates - fermentation: regeneration of NAD+ by creating waste product such as ethanol and lactate
2 ways that we can use GTP in the citric acid cycle
- can be used to phosphorylate ADP to create ATP
2. can be used for anabolic reactions
2 functions of TCA cycle
it has both energetic and biosynthetic functions (oxaloacetate must be regenerated (anapleurotic pathway), otherwise the TCA cycle will stop
the net effect of TCA cycle is the complete oxidation of the acetyl group of the acetyl-coA and the production of (4)
2 CO2
1 GTP (ATP)
3 NADH
1 FADH2
difference between aerobic and anaerobic respiration
aerobic: O2 is the final electron acceptor
anaerobic: other compunds act as terminal electrons acceptor, under anoxic conditions
name of the process that uses the energy produced by respiration to synthesize ATP
oxidative phosphorylation
what is a respiratory chain
series of hydrogen and electron carriers that can undergo oxidation-reduction
composition of complex 1
NADH dehydrogenase, FMN (hydrogen carrier), Fe-S center (electron carrier)
what is Q
quinone, hydrogen carrier
what is complex 2
succinate dehydrogenase, FAD (hydrogen carrier)
what is complex 3
cytochrome bc1, Fe-S (electron carrier)
what is cytochrome c
electron carrier
what is complex 4
electron carrier, terminal oxidase
in eukaryotes, where are the electron transport chain and the TCA enzymes
transport chain: in the mitochondria
TCA enzymes: inside the mitochondria
the proton motive force is used to drive other energy requiring reactions (3)
- flagellum rotation (in bacteria)
- transport accross the membrane
- synthesized of ATP
how many protons are necessary to phosphorylate ADP to ATP
3-4
what are the physical and the chemical components of the proton motive force (pmf)
physical: membrane potential (mV)
chemical: transmembrane pH gradient
why some bacteria (even if they don’t do oxidative phosphorylation) still have ATPase
because ATPase are reversible so they can used it to generate a proton motive force
net yield of energy in the glycolysis
8 ATP
- substrate-level phosphorylation: 2 ATP
- oxidative phosphorylation: (2NADH= 6 ATP)
net yield of energy in the citric acid cycle
15 ATP x 2 = 30 ATP
- substrale-level phosphorylation = 1 GTP (ATP)
- oxidative phosphorylation (4 NADH = 12 ATP + 1 FADH2 = 2 ATP donc 14 ATP)
total of net yield of energy
38 ATP
what happens to the succinate if there is no terminal electron acceptor
the succinate can’t be oxidize by the succinate dehydrogenase in the respiratory chain
net yield of ATP in fermentation
2 ATP
in the absence of oxygen, how the grow of the yeast is affected
the yeast population grows very slowly because fermentation yields only a fraction of ATP produced by respiration
example of fermentation
in yeast, production of ethanol and CO2 is inversely proportional to the concentration of oxygen
