Micro 1- metabolic reactions Flashcards
metabolic pathways are
sequences of enzymatically catalyzed chemical reactions in a cell
oxidation
removal of electrons
reduction
gain of electrons
redox reactions
an oxidation reaction paired with a reduction reaction
oxidative phosphorylation
electrons are transferred from one electron carrier to another along an electron transport chain (system) on a membrane that releases energy to generate ATP
catabolism
releases energy by oxidation of molecules
break down
anabolism
uses energy to synthesize macromolecules that make up the cell
(building)
carbohydrate catabolism is
the breakdown of carbohydrates to release energy
- glycolysis
- krebs cycle
- electron transport chain (system)
where does glycolysis occur and how many steps is it total
it occurs in the cytoplasm
-10 steps total
net gain in glycolysis
glycolysis is the breaking down of glucose sugar
-net gain of 2 ATP for 1 glucose oxidized
additional pathways to glycolysis
- pentose phosphate pathway
- entner-doudoroff pathway
pentose phosphate pathway
- uses pentoses and produces NADPH
- operates simultaneously with glycolysis
entner-doudoroff pathway
- produces NADPH and ATP
- does NOT involve glycolysis
- occurs in pseudomonas, rhizobium, and agrobacterium
Krebs cycle
- pyruvic acid from glycolysis is oxidized and decarboxylation (loss of CO2) occurs
- resulting 2 carbon compound attaches to coenzyme A, forming acetyl coA and NADH
- oxidation of acetyl CoA produces NADH, FADH2, and ATP, and liberates CO2 as waste
in Krebs cycle, 1 molecule of pyruvic acid results in
3 NADH
1 ATP
1FADH2
releases CO2
where does cellular respiration occur?
mitochondrial matrix of eukaryotes
cellular respiration
oxidation of molecules liberates electrons to operate an electron transport chain
-final electron acceptor comes from outside the cell and is inorganic (oxygen)
how is the ATP generated in cellular respiration
by oxidative phosphorylation
where does the electron transport chain system occur
- in the plasma membrane of prokaryotes
- in the mitochondrial matrix of eukaryotes
the electron transport chain is
a series of carrier molecules are oxidized and reduced as electrons are passed down the chain
-energy released is used to produce ATP by chemiosmosis
what is chemiosmosis
electrons (from NADH) pass down the electron transport chain while protons are pumped across the membrane
- establishes proton gradient (proton motive force)
- protons in higher concentration on one side of the membrane diffuse through ATP synthase
- release energy to synthesize ATP
what is the final electron acceptor in the electron transport chain
molecular oxygen (O2)
fermentation releases energy from
the oxidation of organic molecules
what is different about fermentation
- does not require oxygen
- does not use the Krebs cycle or ETC
- uses an organic molecule as the final electron acceptor
- only produces a small amount of ATP
lactic acid fermentation produces:
what 2 types
lactic acid
- homolactic- lactic acid only
- heterolactic- lactic acid and other compounds
what is glucose oxidized to
pyretic acid, which is then reduced by NADH
alcohol fermentation
produces ethanol and CO2
- glucose is oxidized to pyretic acid, pyruvic acid is converted to acetaldehyde and Co2
- NADH reduces acetaldehyde to ethanol
