TCA Cycle Flashcards
Where is the TCA cycle located in prok and euk?
the complete cycle is present in?
If microbes lack a complete cycle then they usually have?
pro- cytoplasmic matrix
euk- mitochondrial matrix
aerobic bacteria, protists, and fungi
the most important cycle enzymes because the TCA cycle is an important source of intermediates for biosynthesis.
AEC controls what?
regulates what?
Anabolic enzymes activated?
What represses catabolic rxs, and what activates them?
AMP is hydrolyzed to?
AEC controls the overall growth of the microbe,
regulating catabolism which synthesizes ATP and anabolism which consumes it
Anabolic enyzmes activated by high EC value
catabolic rxns are repressed by ATP, activated by ADP and AMP
AMP is hydrolyzed to adenosine, for example when nutrients are low this maintains a high EC value and a low rate of ATP synthesis
second law of thermodynamics?
cell’s reponse?
systems change from states of higher order to lesser order (sponetanously)
Cell’s response: order out of chaos, stealing energy from the environment to increase order
Why does this happen? Biosynthesis, entry mechanisms, and survival
entropy measures?
chemical rxns that cause an increase in entropy are?
rxns that cause a decrease in entropy do?
gibbs free energy does what?
entropy is a measure of disorder
chemical rxns that cause an increase in entropy are favored and release of energy
rxns that cause a decrease in entropy increase order (require energy)
Gibbs free energy (G) accounting device used to deduce the entropy change that occurs following a rxn
free energy (delta G) of the reaction is?
(+)=
(-)=
goal is to?
G of the products minus the G of the starting materials, is a measure of disorder created when the rxn occurs
(+)= create order (biosynthesis)
(-)= energy release
goal is to harness the -deltaG that results from converting glucose into CO2 and H2O and use that energy to drive biosynthetic rxns that have a +deltaG
ATP is the fuel for?
for the synthesis of ATP what needs to happen?
ATP is the fuel used for most anabolic rcns, therefore its synthesis is a major objective in a cell.
energy release from glucose needs to be coupled to the synthesis of ATP
substrate level phosphorylation generates energy in the form of ATP (2)
1) oxidative steps in glycolysis gives rise to energy
2) oxidation of G3P and the addition of Pi results in 1,3 diphosphoglycerate – the energy in one of the phosphate bonds is used to transfer the Pi to ADP to form ATP
when a carb is oxidized via respiration what happens?
the energy then?
when a carb is oxidized via respiration energy is generated by passing electrons through a series of electron acceptors and donors until they reach a final electron acceptor (oxygen or nitrate)
the energy is then gradually released during a series of redox rxns and used to pump protons out of the cell via membrane-bound cytochrome systems.
two components that can be changed according to cellular needs?
electrical charge and chemical (pH) components
