BIOCHEM

>>7970157
>what am I missing?

A better teacher.


Jk I just don't remember the one biochemical class I took.

They can be I'm pretty sure. It's just inefficient and rarely ever used. Amino acids are easier to make into glucose, so that's what your body does instead.

>>7970157
>Why cant fats be converted into glucose?

They probably can.
But the encoding the enzymes required to do so would be selected against, because it would be retarded to do so

>>7970160
PEP carboxykinase, which converts OAA to PEP for gluconeogenesis, is definitely present and even required to covert pyruvate back to glucose

File: 300px-Gluconeogenesis_pathway.png (19KB, 300x644px) Image search: [Google]

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>>7970157
Look over your organic chemistry again and then hit your biochemistry text book. Using fats is a very complex and wasteful method of making glucose in comparison. You'd have to spend a lot of energy turning a 2 carbon molecule into a 3 carbon molecule suitable for gluconeogensis.

>>7970215
>2 carbon molecule into a 3 carbon molecule suitable for gluconeogensis

all you need to do is convert OAA to PEP
which happens A LOT when pyruvate needs to be converted to PEP (pyruvate -> OAA -> PEP)

>>7970244
>all you need to do is convert OAA to PEP

*OAA from the citric acid cycle

>>7970157
no answer here
no answer on the internet
no good answer in textbooks

wasted my time
fuck this gay science
shouldve done physics

>>7970244
Still is fairly energy intensive to try to focus on breaking down fats. Biochemistry is for the most part random/redundant due to mutation but minimum effort when alternatives are possible.
>>7970314
Look in your textbook.

>>7970339
Look in your textbook again*
Focus on the reactions, not the words.

>>7970342
the only reasonable explanations i can find is

it does happen, but not often because it lowers citric acid cycle activity too

there is no net gain of any carbon molecules (two enter with acetyl-CoA and two leave as CO2), so technically the fats don't really produce glucose.
you're basically just using OAA to make glucose; resulting in lower citric acid cycle activity

File: FB_IMG_1458698691884.jpg (24KB, 480x378px) Image search: [Google]

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>>7970157

Ok OP here is the deal.

OAA is the first compound to be used in the neoglucogenesis metabolism
If you exclude Pyruvate.

OAA is ALSO the first compound of Krebs Cycle to be condensed with AcetylCoA, To create Citrate.

When you dont eat for a while, Your brain CANNOT consume fatty acid, It needs Glucose (as well as heart muscle). So the liver start producing glucose from Pyruvate That was left in the liver cell as well as OAA coming from Amin Acids That give some compounds of the Krebs Cycle via specific enzymes.
It would be "retarded" to reuse the OAA produced by AAs and pyruvate to condense another Acetyl CoA,
Acetyl CoA produced by fatty acids (this would be active if you were STARVING TO DEATH) start transform to Cetonic Compounds wich are usable by brain and heart unlike Fatty Acids
Brain and Heart are more important to keep than skelletal muscles and pyruvate used for the rest of the body is redirected through creation of Glucose.
I hope I answered your questions OP !

>>7970381
You're pretty much right
Its just not a great idea in comparison to the alternatives.