Exam 4 Flashcards
Rate of NADH oxidation to NAD+ will increase if…
Uncoupler is added
Muscle is active
Rate of NADH oxidation to NAD+ will decrease (buildup of NADH) if…
ATP Synthase inhibited
CO added
Muscle is resting
UCP-1 Found in
Brown Adipose Tissue, NOT white adipose tissue
True or False: Beta Subunits have different affinities for ADP, ATP and Pi
True, they make up the T, O, and L beta subunits
ACC uses _____ as coenzyme
Biotin
ATP Synthesis does not occur unless _____ levels are high
ADP…
Need ADP to convert to ATP. If ADP low, ATP synthesis won’t happen
Substrate for glycogen synthase
UDP-Glucose
What drives formation of UDP-Glucose
hydrolysis of pyrophosphate
UDP-Glucose-Pyrophosphorylase catalyzes!
ACC reaction is reversible or no?
It is irreversible, Malonyl CoA is committed to FAS
Steps of FAS:
- Formation of Malonyl CoA
- Condensation - CO2 Released
- Reduction of Carbonyl to get Alcohol with NADPH
- Dehydration - H2O released
- Reduction of Double Bond with NADPH
- Passing to Condensing Enzyme to grow chain
- Release of Palmitate
Is NADPH used in triglyceride or phospholipid biosynthesis
It is not used in either
Pyruvate carboxylase, function and regulation
Converts Pyruvate to Oxaloacetate, allosterically activated by Acetyl CoA
Acetyl CoA Carboxylase: function, requires ____
Rate limiting step in FAS, adds CO2 to Acetyl CoA to make Malonyl CoA, requires ATP
Sources of NADPH
- Malic Enzyme - breaks malate
2. G-6-P Dehydrogenase - PPP to turn glucose to 5-C ribulose
Allosteric Regulation of ACC
Citrate - Allosterically Activates
Palmitate/Palmitoyl CoA Depolymerizes/inactivates
NADPH is a coenzyme for
Fatty Acid Synthase
If oxygen still consumed, NAD+ accumulates, and something is added it is probably…
Uncoupler
If ETC stops and NADH accumulates, it is…
Either ATP Synthase inhibitor or ETC inhibitor
Respiratory control
Control of O2 consumption by ADP concentration – Control of ETC
What is protonated in the catalytic domain of ATP Synthase
Aspartic acid
Active cell, ATP/ADP/NAD+/NADH levels
Low in NADH, ATP
High in NAD+, ADP
Why is glycogen branched?
Faster synthesis and degradation as multiple enzymes can work at once
Glycogen synthase regulation
I/G ratio - high - activate protein phosphatase and deactivate glycogen synthase kinase.
Dephosphorylation = Active!
Glycogen synthase allosteric regulation
activated by G-6-P
Order of initial steps in Glycogen synthesis
G-6-P –> G-1-P
G-1-P + UTP –> UDP-Glucose
Pyrophosphate cleaved so that glycogenin (protein) can
synthesize the primer to start glycogen chain
Only enzyme in this exam that is active in phosphorylated form
Glycogen phosphorylase - degradation of glycogen. When protein phosphatase is activated, it dephosphorylates and inactivates glycogen phosphorylase
Primary source of carbons for FAS
Excess dietary carbs
FAS made from ____ End to ____ end
Omega (reducing) to Carboxylic acid (non-reducing) end
_______ requires activation steps, _______ does not
Phospholipid biosynthesis requires activation
Triglycerides synthesis does not
Cellulose contains
Only glucose, not fructose
Same with everything else
Glycogen synthesis occurs in
Liver, kidney, intestine, AND muscle
Branching Enzyme aka
It is a type of transferase
Transferase in glycogen degradation
bypass stearic hindrance
Chylomicrons have
Most [TAG], lowest density
LDL has
Most cholesterol content
HDL has
Lowest [TAG], highest density
Lipoprotein Lipase
Activated by insulin, allows for VLDL formation to transport lipoproteins to muscle and adipose tissue
What splits citrate in cytoplasm after transport
ATP Citrate Lyase
F0 Domain of ATP Synthase
Embedded in membrane, C ring
F1 Domain
Catalytic domain, Alpha (spacers) and beta subunits
Malate Aspartate Shuttle, Where, for what
Liver and Heart, to move electrons from cytoplasm to mitochondria
Net yield of ATP per glucose
+30
What drives reduction reactions in FAS
NADPH reducing power
What drives condensation (CO2 release) rxn
Decarboxylation
Pantothenic Acid
Cofactor for Acyl Carrier Protein ACP
Common intermediate for both TAG and phospholipids
Phosphatidate
In presence of uncoupler, fuel consumption ____
Increases
Nothing happens to oxidative phosphorylation though
Activation step of FAS
Add CO2 to Acetyl CoA to make Malonyl CoA
ATP-ADP Translocase
Brings ADP into mitochondria and ATP out to cytoplasm
Name some respiratory inhibitors (different from respiratory CONTROL)
Retenone, Amytal, Antimycin A, CN- (Cyanide), N3 (azide), CO
Coupled with ATP Synthase, so both are inhibited
Inhibitors of ATP Synthase
Oligomycin
DCCD
Coupled with ETC, so both are inhibited
Uncouplers
Shuttle protons across membrane, based on pH gradient
Ex. dinitrophenol
Alpha linkage
Alcohol is TRANS to aldehyde
Beta Linkage
Alcohol is CIS to aldehyde
Alcohol + ketone =
Hemiketal
Where does Liver get glycerol for TAG synthesis
Glycerol Kinase
Where does Adipose tissue get glycerol
Relies only on glycolysis to produce Dihydroxyacetone phosphate DHAP
Important functional group in ACP
Sulfhydryl group
