test 3 Flashcards
in muscle and bacteria, pyruvate is reduced to…
lactate
one of most critical steps in EMP pathway
fructose bisphosphate aldolase
what happens to pyruvate in yeast?
cleaved to CO2 and acetaldehyde and then converted to ethanol
the three irreversible steps in EMP
- pyruvate kinase (PEP to pyruvate)
- phosphofructokinase (F-6-P to F-1,6-bP)
- hexokinase (Glu to G-6-P)
Glycogen synthesis uses which 2 enzymes?
- ADP glucose phosphorylase
2. glycogen synthase
Why does the pentose phosphate pathway generate NADPH?
for reducing power in converting alpha-ketoglutarate to glutamate OR incorporation of acetate into fatty acids
general equation of pentose phosphate pathway (PPP)?
3 G6P –> 2F6P + 1 Ga3P
glycogen is cleaved by
glycogen phosphorylase
starch is cleaved by
beta-amylase (cuts to maltose units)
maltose is cleaved by
amylotransferase, alpha-amylase, and 4-alpha-glucanotransferase
what happens to TCA intermediates?
they are used for anabolic reactions
purpose of the glyoxylate cycle?
replenishes oxaloacetate
glyoxylate shunt equation
2 acetyl CoA –> 1 malate
isocitrate lyase converts what to what
isocitrate to succinate and glyoxylate
what does malate synthase do?
couples acetyl coA and glyoxylate for form malate
role of F1F0 type ATP synthase
generation of ATP from the proton motive force (PMF)
two parts of F1F0 type ATP synthase
- F1 - attached to membrane by pore complex called F0 (synthesizes ATP)
- F0 - conductor of H+ across membrane
how many H+ to generate 1 ATP?
3-4
when ATPase works in reverse it pumps protons out of cell and generates PMF to drive what?
flagellar movement
energy yield depends on what factors?
- cytochrome system
- terminal electron acceptor type
- efficiency of ATP synthase
total yield per glucose molecule?
~38 ATP per glucose in respiring bacteria
chemoautotroph
obtains C from organic compounds but obtains E from oxidation of inorganic compounds
photoautotrophs
obtains C from organic compounds but obtains E from light
what is the sodium motive force and when is it used?
when ATPase couples ATP synthesis to movement of Na+ (NOT H+)
it occurs in alkaline conditions
photoautotroph bacteria
- carry out photosynthesis
- convert E from sun, CO2 and water to organic compounds
- use bacteriochlorophyll
- derive H from H2S
Photoheterotrophic bacteria
-combine photosynthetic and catabolic process for metabolism
-CANNOT fix CO2 to organic materials
use light for E
-contain bacteriochrolophyll and bacteriorhodopsin
2 branches of anaerobic TCA
- one branch acts as reductive pathway to reverse succinate to oxaloacetate
- another path converts oxaloacetate to alpha-ketoglutarate oxidatively
what is the purpose of fermentation?
to replenish NAD+ depleted during glycolysis
the phosphoketolase/monophosphate pathway produces?
lactate + ethanol + CO2
what is the Pasteur effect?
in resting yeast cell suspension fermenting glucose, introduction of O2 ceases ethanol formation
(not exhibited by growing yeast cells)
Two types of lactic acid fermentations:
- homofermentative: produce primarily lactic acid
2. heterofermentative: produce lactic acid + other product
Mixed acid fermentation
in anaerobic conditions and absence of alternate e acceptors, enterobacteriaceae ferment glucose to a mixture of:
- acetic acid
- formic acid
- lactic acid
- succinic acid
- ethanol
(Acetate and formate as major products)
