glycolysis Flashcards
what is the main objective of glycolysis?
THE OBJECTIVE OF THE PATHWAY IS TO PHOSPHORYLATE ADP TO FORM ATP; PYRUVATE IS A WASTE PRODUCT, WHICH CAN BE USED FURTHER IN CERTAIN CONDITIONS
what are the products of glycolysis?
2ATP, 2 PYRUVATE AND 2NaDH
name and describe the two phases of glycolysis?
PREPARATORY PHASE: INVOLVES THE PHOSPHORYLATION OF GLUCOSE. THE PRODUCT IS THEN SPLIT TO YIELD TWO THREE-CARBON MOLECULES.
* PAYOFF PHASE: THIS IS PHASE WHERE ENERGY IS RELEASED, AS TWO MOLECULES OF 1,3-BISPHOSPHOGLYCERATE ARE CONVERTED TO TWO
MOLECULES OF PYRUVATE
what is the net production of ATP and how many are used in the preparatory phase?
THIS PATHWAY RESULTS IN THE PRODUCTION OF FOUR ATP MOLECULES PER MOLECULE OF GLUCOSE USED. HOWEVER, THE NET YIELD IS TWO ATP AS TWO WERE INVESTED IN THE FIRST PHASE
where is the phosphorylation of glucose carried out?
it is carried out in the liver by hexokiniase D type IV aka glucokinase.
name the first ATP producing reaction of glycolysis?
the conversion of 1,3 bisphosphoglycerate to 3 phosphoglycerate using the enzyme phosphoglycerate kinases (step 7 in glycolysis) (substrate level phosphorylation)
what is the second ATP forming reaction?
phosphoenolpyruvate to pyruvate catalyzed by mpyruvate kinase ( substrate level phosphorylation)
what is an allosteric enzyme and give an example in glycolysis.
an allosteric enxyme is an enzyme that has an additional site called a regulatory or allosteric site that allows binding of a regulatory molecule. for example phosphofrutokinase
how does phosphofrutikinase work
a high level of ATP inhibits the enzyme by decreasing its affinity to fructose 6 phosphate
what is fermentation
is the name given to glycolytic pathways
in which the excess electrons are dumped onto a waste
biomolecule. Anaerobic degradation of glucose or other
nutrients to obtain energy which is conserved as ATP
what are the different typers of fermentation?
Homolactic fermentation s when each of the two
molecules of pyruvate formed from glucose are given the
two electrons on NADH making two molecules of lactate
and two NAD+.
Ethanolic fermentation occurs when the pyruvate is first
decarboxylated before reduction.
say everything you know about fermentation.
FERMENTATION IS THE PROCESS BY WHICH LIVING
ORGANISMS RECYCLE NADH NAD+ IN THE ABSENCE OF
OXYGEN.
* USED TO REGENERATE NAD+ WHICH IS USED IN GLYCOLYSIS.
* ALL FERMENTATION PROCESSES OCCUR UNDER ANAEROBIC CONDITIONS AND BEGIN WITH PYRUVATE.
* FOR ANIMALS THIS PROCESS INVOLVES THE CONVERSION
OF PYRUVATE TO LACTATE.
* FOR MICROORGANISMS THERE ARE MANY PATHWAYS.
* MICROBIAL FERMENTATION ARE USED FOR THE PRESERVATION OF FOODSTUFF AND ALCOHOLIC BEVERAGES
examples: propionibacterium- propanoic acid to produce swiss cheese
aspergacillus lactobacillus streptococcus- lactic acid- cheddar cheese and yogurt
sacharomyces- ethanol- wine and beer
which enzyme is used in lactic acid fermentation
Lactate dehydrogenase producing NAD+ in the process
where and under what condition does lactic acid fermentation take place.
in hypoxic conditions in oxygen depleted muscles
describe the two steps in alcohol fermentation
step 1: PYRUVATE CONVERTED TO ACETALDEHYDE USING
THE ENZYME PYRUVATE DECARBOXYLASE AND RELEASING CO2
step 2: ACETALDEHYDE IS CONVERTED INTO ETHANOL
USING ALCOHOL DEHYDROGENASE AND PRODUCING
NAD+ IN THE PROCESS.
