chapter 7-metabolism Flashcards
what is metabolism
the sum of all chemical rxns that occur in the body
what is carbolic rxns and anabolic runs
- Catabolic rxn: breaks down chemicals and release energy
- Anabolic rxn: synthesize chemicals and require energy
what is cellular respiration
describes the biochemical conversion of chemical energy stored in molecular bonds into usable energy (ATP)
-A catabolic process
what are the 2 major pathways of cellular respiration
anaerobic and aerobic respiration
what is internal and external respiration
- internal respiration: exchange of gas between individual cells and the extracellular fluid
- External respiration: inhaling and exhaling of air into and out of the lungs as well as the exchange of gas between alveoli and the blood
which mc are the favoured fuel mc and why
carbohydrates and fats bc of the high # of energy rich C-H bonds
end products of metabolisms are?
H2O and CO2 –> low energy bonds
during cellular respiration the oxidation of what releases energy
C to Co2
what does glycolysis literally mean and what does it lead to
- sugar breaking
- leads to the oxidative breakdown of glucose into 2 mc of pyruvate, the production of ATP and the reduction of NAD+ to NADH
what gets reduced and what get oxidized during glycolysis
glucose is reduced and NAD+ is oxidized
where does glycolysis occur
cytoplasms
can prokaryotic and eukaryotic cells undergo glycolysis
yes
glycolysis is divided into 3 stages what are they
1) energy investment stage
2) cleavage stage
3) energy payout stage
what is the energy investment stage during glycolysis
-2 ATPs are used to add 2 phosphate groups to glucose producing fructose 1, 6 biphosphate ( 6 C) and these actions are completed by kinases
oGlucose glucose 6 phosphate fructose 1,6 biphosphate
what is the cleavage stage of glycolysis
-splits fructose 1,6 biphosphate into glyceraldehyde 3 phosphate and dihydroxyacetone phosphate
oglyceraldehyde 3 phosphate (PGAL) and dihydroxyacetone phosphate (DHAP) are 3 C cpd with a phosphate added
oDHAP is then isomerized to form a second PGAL
what is the energy payout stage
results in the production of ATP
o PGAL–> 1,3 diphosphoglycerate–> 3-phosphoglycerate –>2-phosphoglycerate phosphoenolpyruvate–>pyruvate
oWhen pyruvate gets formed the reduction of NAD+ to NADH occurs which is catalyzed by dehydrogenase) and the production of 2 ATP catalyzed by kinases
o this stage occurs 2 times per mc of glucose
what catalyzes the reduction of NAD+ to NADH during glycolysis
dehydrogenase
what catalyzes the production of ATP during the energy payout stage of glycolysis
kinase
1 mc of ATP produce
1 ) __ mc of pyruvate
2) __ ATP
2 and 2
what is substrate level phosphorylation and an ex
ATP synthesis is directly coupled with the oxidation of glucose without participation of an intermediate mc such as NADH or FADH2
- ex is the product of ATP from glycolysis
what is substrate level phosphorylation
does require an intermediate e carrier such as NADH or FADH2
what is the net rxn of glycolysis
glucose + 2ADP + 2Pi + 2NAD+–> 2 pyruvate + 2ATP + 2 NADH + 2H+ + 2H2O
what are 2 things that can happen to pyruvate after glycolysis
- pyruvate can be reduced during fermentation
- pyruvate is further oxidized during cellular respiration in the mitochondria
what occurs to pyruvate during anaerobic respiration
-NAD+ must be regenerated for glycolysis to continue in the absence of O2 which is done by reducing pyruvate into ethanol or lactic acid via fermentation
what are the 2 types of fermentation that occurs to pyruvate
alcohol fermentation and lactic acid fermentation
what is alcohol fermentation
it occurs in yeast and some bacteria
-The pyruvate produced in glycolysis is converted to ethanol in this way NAD+ is regenerated and glycolysis can continue
what is lactic acid fermentation
occurs in certain fungi and bacteria and in human muscles during strenuous activity
- When O2 supply to muscle cells lag behind the rate of glucose catabolism, the pyruvate generated is reduced to lactic acid
- The NAD+ is regenerated when pyruvate gets reduced
how many ATP are produced during aerobic respiration and anaerobic respiration
36-38 and 2
aerobic respiration an be divided into 3 stages what are they
pyruvate decarboxylation, the citric acid cycle, ETC
where does pyruvate decarboxylation, the citric acid cycle, ETC occur in EUK and PROk
mitochondria, cytoplasm
what electron carriers
NadH and FADH2
what occurs during citric acid cycle
Acetyl-coA then undergoes the citric acid cycle producing electron carriers NadH and FADH2 and regenerating oxaloacetate then repeat of cycle
where is the ETC located
inter membrane space
where in prokaryotes ETC is located
on the bacterial membrane itself