Unit II Fat Synthesis Flashcards
What are the two glucose transporters for getting it into a cell?
Sodium independent glucosetransporters (GLUT) and sodium-monosaccharide co-transport system (SGLT)
Of the two glucose transporters which one requires ATP?
SGLT
Which glucose transporter trasnports against the gradient?
SGLT
In what tissue will GLUT4 be most present?
Muscle tissue
In what tissue will GLUT2 be most present?
Liver tissue
What hormone is GLUT4 regulated by?
insulin
Which GLUT transporter only deals with glucose?
GLUT4
Which GLUT transporter will carry glucose, galactose, and fructose?
GLUT2
The transporter that works via facillitated diffusion
GLUT4
Where does about 90% of insulin stimulated glucose uptake occur?
in skeletal muscle
Exercise will stimulate the accumulation of which transporter for 1-2 hours post-exercise?
GLUT4
Adding a phosphate to glucose in a muscle cell will allow what to happen?
That phosphate will help keep glucose concentrations low and for more glucose to keep flowing in
What will happen to gluocse-6-phosphate in a muscle cell with a low energy charge?
G-6-P will run through glycolysis, a prep step, andkrebs and make more ATP
What will happen to G-6-P when muscle glycogen is low?
G-6-P gets converted to glycogen
In a muscle cell, if there is a lot of gycogen and energy, what will be inhibited?
PFK
In a muscle cell, if G-6-P has accumulated, what will be inhibited?
hexokinase
In a muscle cell, when glucose accumulates, what will be inhibited?
facillitated diffusion of glucose is inhibited
If the muscle cell is full of glucose, where will the extra be sent to?
the liver
In the liver, wht enzyme will setup glucose for use in building fat?
glucokinase
What stimulates glucokinase?
insulin and fructose
As G-6-P accumulates, would it inhibit glucokinase?
no it does not
In what tissue would fructokinase and triokinase be most expressed?
the liver
After running through the Fructose-1-Phosphate pathway, how will fructose enter glycolysis?
As glyceraldehyde-3-Phosphate (G-3-P)
In what tissue is the primary metabolism site of fructose?
the liver
In what tissue is the primary site of fatty acid synthesis?
the liver
What specific siteof a cell does fatty acid synthesis takeplace?
the cytosol
What is the main coenzyme of fatty acid synthesis?
NADPH
In order to get acetyl-CoA from the matrix into the cytosol, what must it be converted to?
citrate
What enzyme combiones acetyl CoA and oxaloacetate to make citrate?
citrate synthase
What does citrate spilling into the cytosol signal?
high energy in the cell
What enzyme creates OAA and acetyl- CoA from cytosolic citrate?
citrate lyase
What enzyme creates Malonyl CoA from acetyl CoA?
acetyl CoA carboxylase (ACC)
What coenzyme is required for ACC to run?
biotin
Besides a coenzyme what else does the carboxylation of acetyl CoA require?
CO2 and ATP
What is the rate limiting step of FA synthesis?
ACC
In inactive form, what is ACC?
a protomer
What inactivates ACC?
long chain fatty acid acyl CoA
What compounds can phosphorylate and inactivate ACC?
AMPkinase and cAMP
What hormone can activate ACC?
insulin
List the inhibitors of ACC
malonyl CoA, palmitate, epinephrine, and glucaon
List the stimulators of ACC
insulin and citrate
What multienzyme complex will combine malonyl and acetyl?
Fatty acid synthase (FAS)
What portion of FAS does the comining of malonyl and acetyl?
acyl carrier protein (ACP)
To create Acetoacetyl-ACP, what enzyme will combine acetyl ACP and malonyl ACP?
Beta-ketoacyl-ACP SYNTHASE
What enzyme will create D-3-Hydroxybutyryl-ACP from acetoacetyl-ACP?
Beta-Ketoacyl-ACP REDUCTASE
What enzyme will createCrtonyl-ACP from D-3-Hydroxybutyryl-ACP?
Beta-hydroxyacyl-ACP DEHYDRASE
What enzyme will create Butyryl-ACP from noyl-Crotonyl-ACP?
Enoyl-ACP REDUCTASE
What is the final stepo of FA synthesis?
Palmitate (16:0)
Which two steps of FAS will use NADPH?
the reduction steps
What enzyme will release palmitate from FAS?
palmitoyl thioesterase
The elongation of palmitate is accomplished by what enzyme?
elongases
What coenzyme is required with elongase?
NADPH
The desaturation and creation of a double bond in palmitate is accomplished by what enzyme?
desaturases
