BB 451 midterm 1 questions with
verified answers graded A+
energy sources for cells - correct answer ✔✔sugars from carbs
amino acids from proteins
fatty acids from fats
"beginning" of CAC - correct answer ✔✔entry of acetyl-CoA
cataplerotic - correct answer ✔✔amino acids producing intermediates that are
broken down in the CAC
anaplerotic - correct answer ✔✔producing ntermediates that can be used to
make amino acids
pyruvate dehydrogenase - correct answer ✔✔converts pyruvate into acetyl-CoA
for CAC
-in mitochondria
-requires pyruvate from cytoplasm to be transported to mitochondria
components of pyruvate dehydrogenase - correct answer ✔✔pyruvate
decarboxylase (E1)
dihyrolipoamid transaceetylase (E2)
,dihyrolipoamide dehydrogenase (E3)
pyruvate dehydrogenase regulation - correct answer ✔✔by:
-substrate level (NAD+/NADH_
-allosteric (ATP inactivates, AMP/ADP activate)
-covalent modification (de/phosphorylation)
kinase - correct answer ✔✔phosphorylates (puts on Pi) on PDH which inactivates
it
phosphatase - correct answer ✔✔dephosphorylates PDH, activating it
Citric Acid Cycle (CAC) - correct answer ✔✔-occurs in mitochondria
-3 NADH
-1 FADH2
-1 high energy phosphate (GTP animals, ATP plants/bac)
***for 1 acetyl-CoA (2 acetyl-CoA per 1 glucose = CAC 2x)
1st part of CAC - correct answer ✔✔release of CO2
2nd part of CAC - correct answer ✔✔conversion to oxaloacetate
oxaloacetate - correct answer ✔✔converted into citrate in CAC
, Glyoxylate Cycle - correct answer ✔✔-occurs in plants/bac
-needs isocitrate lyase and malate synthase
-plants/bac able to form glucose from acetyl-CoA (where animals can't) bc they
bypass decarboxylation s of CAC and convert acetyl-CoA into useful shit
isocitrate lyase - correct answer ✔✔catalyzes cleavage of isocitrate -> glyoxylate +
succinate
malate synthase - correct answer ✔✔catalyzes acetyl-CoA + glyoxylate = malate
CAC regulation - correct answer ✔✔low NAD+/high NADH = inhibit CAC
high NAD+/low NADH= favor CAC
glyoxylate cycle reguation - correct answer ✔✔preferred when NAD+ is low, bc
only needs 1 NAD+ and 1 FAD per turn of cycle
ketone body - correct answer ✔✔made from acetyl-CoA; important when there
isn't a lot of glucose in animals
-requires 3 acetyl-CoA, 1 is split off to make the 4-C acetoacetate
-soluble in aqueous environments aka blood; better quick energy sources than
fat/fatty acids
acetoacetate - correct answer ✔✔chemically unstable and readily convert to
acetone
verified answers graded A+
energy sources for cells - correct answer ✔✔sugars from carbs
amino acids from proteins
fatty acids from fats
"beginning" of CAC - correct answer ✔✔entry of acetyl-CoA
cataplerotic - correct answer ✔✔amino acids producing intermediates that are
broken down in the CAC
anaplerotic - correct answer ✔✔producing ntermediates that can be used to
make amino acids
pyruvate dehydrogenase - correct answer ✔✔converts pyruvate into acetyl-CoA
for CAC
-in mitochondria
-requires pyruvate from cytoplasm to be transported to mitochondria
components of pyruvate dehydrogenase - correct answer ✔✔pyruvate
decarboxylase (E1)
dihyrolipoamid transaceetylase (E2)
,dihyrolipoamide dehydrogenase (E3)
pyruvate dehydrogenase regulation - correct answer ✔✔by:
-substrate level (NAD+/NADH_
-allosteric (ATP inactivates, AMP/ADP activate)
-covalent modification (de/phosphorylation)
kinase - correct answer ✔✔phosphorylates (puts on Pi) on PDH which inactivates
it
phosphatase - correct answer ✔✔dephosphorylates PDH, activating it
Citric Acid Cycle (CAC) - correct answer ✔✔-occurs in mitochondria
-3 NADH
-1 FADH2
-1 high energy phosphate (GTP animals, ATP plants/bac)
***for 1 acetyl-CoA (2 acetyl-CoA per 1 glucose = CAC 2x)
1st part of CAC - correct answer ✔✔release of CO2
2nd part of CAC - correct answer ✔✔conversion to oxaloacetate
oxaloacetate - correct answer ✔✔converted into citrate in CAC
, Glyoxylate Cycle - correct answer ✔✔-occurs in plants/bac
-needs isocitrate lyase and malate synthase
-plants/bac able to form glucose from acetyl-CoA (where animals can't) bc they
bypass decarboxylation s of CAC and convert acetyl-CoA into useful shit
isocitrate lyase - correct answer ✔✔catalyzes cleavage of isocitrate -> glyoxylate +
succinate
malate synthase - correct answer ✔✔catalyzes acetyl-CoA + glyoxylate = malate
CAC regulation - correct answer ✔✔low NAD+/high NADH = inhibit CAC
high NAD+/low NADH= favor CAC
glyoxylate cycle reguation - correct answer ✔✔preferred when NAD+ is low, bc
only needs 1 NAD+ and 1 FAD per turn of cycle
ketone body - correct answer ✔✔made from acetyl-CoA; important when there
isn't a lot of glucose in animals
-requires 3 acetyl-CoA, 1 is split off to make the 4-C acetoacetate
-soluble in aqueous environments aka blood; better quick energy sources than
fat/fatty acids
acetoacetate - correct answer ✔✔chemically unstable and readily convert to
acetone
