BIOC3022 Exam 4 Questions With Complete Solutions
how are acyl-CoA molecules transferred into the mitochondria?
Correct Answers by having a carnitine group added to it. From
CPT1. And then CACT (translocase for carnitine) transfers it
across the inner mito membrane.
How are amino acids joined together? Know the bond name and
the groups that are linked. Correct Answers individual amino
acids are linked with peptide bond to make up protein
alpha amino group of one amino acid is linked to nitrogen of a
second amino acid
how can DNA damage/repair contribute to cellular aging?
Correct Answers cellular senescence (lead to age issues):
accumulating DNA damage leads to cell cycle arrest (unable to
proliferate). DNA damaged cells also become resistant to
apoptosis and accumulate with aging.
Senolytics clear senescent cells can be a therapeutic.
defects of cellular functions and cell death & senescence lead to
aging and leads to decline the efficiency and accuracy of DNA
repair
How is cycling between fatty acid synthesis and degradation
avoided? why do we want to avoid it? Correct Answers
Quantities of malonyl CoA and citrate regulate whether
synthesis or oxidation is occurring
,Malonyl CoA is a regulatory molecule for Fatty acid synthesis
and also inhibits CPT1 allosterically.
Reduced malonyl CoA enables FFA oxidation and energy
production
Citrate also regulates PFK and glycolysis rates- excess signals to
glycolysis to slow down and pushes C through PPP producing
NADPH to make FFA
how is glycerol used? Correct Answers is converted to DHAP
and sent to gluconeogenesis
how is one carbon metabolism used? (broadly but know what
molecule donates carbons to purine/pyrimidine rings, and when
in each biosynthesis pathway it happens) Correct Answers
Know the serine/dTMP/thymidylate synthase reaction and
concepts of one carbon metabolism being required for
nucleotide synthesis, plus which carbons in the nucleotide rings
are donated by one carbon metabolism.
dTMP synthesis is linked to one-carbon metabolism.
one-carbon carrier+ dUMP reacted with Thymidylate
synthase** makes dTMP.
tetrahydrofolate also is a carrier that interacts with step 3 of
purine sysnthesis to make IMP??????????????
how is transaminase reaction stabilized? Correct Answers by
Pyridoxal phosphate (PLP):
1. PLP (enzyme bound) reacts with AA forming a Schiff base
(C=N)
, 2. Shift of double bond, a-keto acid is released through
hydrolysis of schiff base and PLP is produced
3. Pyridoxamine phosphate then forms a Schiff base with a-keto
acid
4. After double bond shifts, AA is released through hydrolysis of
the Schiff base and enzyme bound-PLP is regenerated.
---> amino group from first AA is transferred to second AA
how is triglyceride mobilized from adipocytes? Correct
Answers lipolysis.
Uses lipases to release fatty acids from triglycerides. Lipolysis
in adipose tissue is stimulated by hormones that respond to
fasting (glucagon) or stress (epinephrine)
Hormone stimulation of GPCR activates adenylyl cyclase,
increasing cAMP and activating PKA which then
phosphorylates lipases to activate. These reactions release fatty
acid from glycerol backbone
hormonal control of triacylglycerol lipase, then diacylglycerol
lipase, then monoacylglycerol lipase to liberate all 3 fatty acids
from glycerol backbone.
how is uric acid produced? Correct Answers purine metabolism
hypoxanthine is an intermediate product to uric acid
-Purine salvage pathway and xanthine oxidase makes uric acid.
AMP is starting product in making hypoxanthine. GMP is
starting product to make Xanthine.
-Hypoxanthine can be converted into xanthine using xanthine
oxidase
how are acyl-CoA molecules transferred into the mitochondria?
Correct Answers by having a carnitine group added to it. From
CPT1. And then CACT (translocase for carnitine) transfers it
across the inner mito membrane.
How are amino acids joined together? Know the bond name and
the groups that are linked. Correct Answers individual amino
acids are linked with peptide bond to make up protein
alpha amino group of one amino acid is linked to nitrogen of a
second amino acid
how can DNA damage/repair contribute to cellular aging?
Correct Answers cellular senescence (lead to age issues):
accumulating DNA damage leads to cell cycle arrest (unable to
proliferate). DNA damaged cells also become resistant to
apoptosis and accumulate with aging.
Senolytics clear senescent cells can be a therapeutic.
defects of cellular functions and cell death & senescence lead to
aging and leads to decline the efficiency and accuracy of DNA
repair
How is cycling between fatty acid synthesis and degradation
avoided? why do we want to avoid it? Correct Answers
Quantities of malonyl CoA and citrate regulate whether
synthesis or oxidation is occurring
,Malonyl CoA is a regulatory molecule for Fatty acid synthesis
and also inhibits CPT1 allosterically.
Reduced malonyl CoA enables FFA oxidation and energy
production
Citrate also regulates PFK and glycolysis rates- excess signals to
glycolysis to slow down and pushes C through PPP producing
NADPH to make FFA
how is glycerol used? Correct Answers is converted to DHAP
and sent to gluconeogenesis
how is one carbon metabolism used? (broadly but know what
molecule donates carbons to purine/pyrimidine rings, and when
in each biosynthesis pathway it happens) Correct Answers
Know the serine/dTMP/thymidylate synthase reaction and
concepts of one carbon metabolism being required for
nucleotide synthesis, plus which carbons in the nucleotide rings
are donated by one carbon metabolism.
dTMP synthesis is linked to one-carbon metabolism.
one-carbon carrier+ dUMP reacted with Thymidylate
synthase** makes dTMP.
tetrahydrofolate also is a carrier that interacts with step 3 of
purine sysnthesis to make IMP??????????????
how is transaminase reaction stabilized? Correct Answers by
Pyridoxal phosphate (PLP):
1. PLP (enzyme bound) reacts with AA forming a Schiff base
(C=N)
, 2. Shift of double bond, a-keto acid is released through
hydrolysis of schiff base and PLP is produced
3. Pyridoxamine phosphate then forms a Schiff base with a-keto
acid
4. After double bond shifts, AA is released through hydrolysis of
the Schiff base and enzyme bound-PLP is regenerated.
---> amino group from first AA is transferred to second AA
how is triglyceride mobilized from adipocytes? Correct
Answers lipolysis.
Uses lipases to release fatty acids from triglycerides. Lipolysis
in adipose tissue is stimulated by hormones that respond to
fasting (glucagon) or stress (epinephrine)
Hormone stimulation of GPCR activates adenylyl cyclase,
increasing cAMP and activating PKA which then
phosphorylates lipases to activate. These reactions release fatty
acid from glycerol backbone
hormonal control of triacylglycerol lipase, then diacylglycerol
lipase, then monoacylglycerol lipase to liberate all 3 fatty acids
from glycerol backbone.
how is uric acid produced? Correct Answers purine metabolism
hypoxanthine is an intermediate product to uric acid
-Purine salvage pathway and xanthine oxidase makes uric acid.
AMP is starting product in making hypoxanthine. GMP is
starting product to make Xanthine.
-Hypoxanthine can be converted into xanthine using xanthine
oxidase
