Ketone Bodies (mini-test 1 AND 2) Flashcards
Once glycogen is gone, proteins in skeletal muscle gets broken down to AAs to make glucose and in this process, malate will be shuttled out of the mitochondria and converted to OAA. So after a week of fasting and protein breakdown….
there will be low malate and OAA in TCA cycle and it needs to be replaced!
Are ketone bodies made in fed state or fasting state?
fasting state
What are ketones used for?
brain fuel (the brain only likes glucose or ketone bodies)
During fasting state what gets used up to help fuel the brain and for how long?
1) liver glycogen is used within 12 hours
2) muscles break down to AAs (muscles provide 50% of energy to the brain)
3) lipids will provide very little energy, but will still be used
4) after 1 week, fat is broken down to ketone bodies
If insulin is high, then will ketone bodies be generated?
NO
During fasting state what gets used up to help fuel the muscles in order?
1) ATP
2) creatinine-P
3) glucose
4) muscle glycogen
5) FAs
6) ketone bodies
3 molecules are ketone bodies. What are the 3?
1) acetoacetate (2 acetones)
2) beta hydroxybutyrate (4C, beta carbon has OH)
3) acetone
You can convert one ketone body to another. Acetoacetate to beta hydoxybutyrate is what type of reaction?
reduction reaction
You can convert one ketone body to another. Beta hydroxybutyrate to acetoacetate is what type of reaction?
oxidation reaction
You can convert one ketone body to another. acetoacetate to acetone is what type of reaction?
spontaneous decarboxylation
Ketone bodies are ________ soluble fuels, so they can enter the brain
water
Ketone bodies are typically exported by the liver and produced naturally at ____ levels
low
Ketone bodies are acidic, so if theres a buildup then it can cause….
ketoacidosis (or less severe version is ketosis)
When are ketone bodies overproduced?
when theres a depletion of OAA
-so starvation mode or untreated DM (body thinks its starving)
What diet is dangerous for diabetics?
keto/atkins diet
What organ generates/produces ketone bodies but CANNOT use them?
liver
How is ketosis diagnosed?
sweet smell of acetone through a person’s breath
What tissues cannot use ketone bodies?
1) liver bc TCA is not working due to ketone bodies built up
2) RBCs bc theres no mitochondria
Ketone bodies are formed from what molecule?
acetyl CoA
Ketone bodies are exported out of liver as energy source to the….
-heart
-skeletal muscles
-kidneys
-brain
During starvation or keto/atkins diet, OAA is mainly used for….
gluconeogenesis in the liver