Catabolism of fatty acids- beta oxidation Flashcards
what are fatty acids
are fuel molecules stored as triacylglycerols
what are triacylglycerols
uncharged esters of fatty acids with glycerol
what is created during the oxidation of fatty acids
energy
what is formed during fasting/ uncontrolled type 1 diabetes
ketosis and ketoacidosis
what is lipolysis
the hydrolysis of triacylglyerol stored in adipose tissue to fatty acids
where are triacylglycerol stored
in adipose tissue
what does lipolysis depend on
our hormone sensitive lipids
what can the glycerol from lipolysis be converted into
DHAP which can be converted back into GAP for our aerobic respiration cycle
what is the relationship between free fatty acids and the time exercising
as the time exercising increases the amount of free fatty acid conc in the blood also increases
what hormones can influence free fatty acid conc in the blood
adrenaline and glucagon
describe the b oxidation overview
fatty acids are highly reduced
they can be oxidised bY nad+ and FAD and they can enter the ETC
also can be converted into Acetyl COA and oxidised by NAD+ and FAD in the TCA cycle
how are fatty acids activated
1.COA+ fatty acid—-> acyl COa( via acyl coa synthase)
which uses ATP and form AMP + PPi—-> 2Pi via the enzyme pyrophosphatase
2.acyl coA is bought into the mitochondrial space and needs to be bought into the matrix for beta oxidation
3. Acyl CoA + CARNATINE—> acylcarnatine +CoA via carnitine acyltransferase
4. use acyl carnation translocase to shuttle across into the inner membrane
5.acylcarnatine—-> acylCoA + carnatine via carnitine acyltransferase II
what are the steps of beta oxidation in oxidation stage 1.
- oxidation- from acyl CoA via Acyl CoA dehydrogenase to form trans delta2 enoyl CoA and producing reduced
FAD
what are the steps of beta oxidation in hydration stage 2.
trans delta2 enoyl CoA is converted into hydroxyacyl CoA via hydrolysis and enoyl CoA hydratase
what are the steps of beta oxidation in oxidation stage 3.
hydroxyacyl CoA concerted into B hydroxyacyl CoA dehydrogenase and produces 1 NADH and ketoacyl CoA
what are the steps of beta oxidation in thiolysis stage 4
ketoacyl CoA converted into acyl coA and myristol coA( back to step 1) via ketoacyl CoA thiolase and using CoA-SH
what is the step 1 oxidation for myristol CoA
myristol coA converted into
how much ATP does one NADH made
2.5 ATP
what double bonds do natural unsaturated fatty acids have
cis double bonds
what does vitamin b12 deficiency cause
anaemic due to effects on folic acid metabolism
what can cause neurological disorders
build up of metabolic products from odd c fatty acids metabolism and they accumulate in myelin sheaths
how do we regulate b oxidation
from hormone sensitive lipase when converts triacylglycerol into glycerol and fatty acids
how do hormone sensitive lipase work q
- activated by adding a phosphate group on the lipase
2. inactivated by removing the phosphate group via phosphatase
what hormone effects (up regulates) phosphatase activity
insulin
what can activate hormone sensitive lipase
protein kinase which uses ATP this is unregulated by CAMP
what molecule is protein kinase upregulated by
cAMP
what molecule up regulates cAMP
glucagon
adrenaline
noradrenaline
what inhibits cAMP
insulin
which molecule inhibits carnitine acyltransferase 1
malonyl CoA
what are ketone bodies
they transport liver acetyl CoA in the blood to other organs for use as fuel for brain, heart and muscle
what is ketosis
normal physiological response to fasting or low carb diet
what is ketoacidosis
abnormally high levels of ketone bodies in the blood reduces the ph and causes coma and death( typically in type 1 diabetes or low carb diet)
what is the characteristic when there is a high amount of ketone bodies in the liver
fruity smell breath
describe diabetic ketoacidosis
blood glucose levels very high due to the inability to take up glucose and liver is running gluconeogensis
because there is no insulin the liver thinks the patient is fasting and causes the flooding of ketone bodies in the blood
what does xs ketone bodies in the blood cause
drop the pH confusion abdominal pain unconsciousness and possibly death kussmaul breathing also causes a lot of water and electrolyte loss leading to dehydration
how do we help patients with diabetic ketoacidosis
fluids electrolytes to restore salt and dilution of ketone bodies
and insulin injections