MET :O Flashcards
which immune cells do you find in the liver? [1]
which cells make bile? [1]
what is composition of bile? [lots]
which immune cells do you find in the liver? [1]
kupffer
bile made by hepatocytes
Water
Bilirubin cholesterol Fatty acids
Lecithin
Ions
Bile salts:
Synthesised from cholesterol -> cholate/chenodeoxycholate
These are conjugated as glycine/taurine and then secreted as sodium salts.
Have detergent properties
This allows them to help is absorb lipophilic substances:
Secretin secretion is caused by acid chyme in the duodenum
This stimulates biliary ductal cells to release bile to neutralise the acid.
what is bilirubin?
what is jaundice?
Bilirubin:
•RBC breakdown in spleen
•Bilirubin bound to albumin
Jaundice: Yellowing of skin and sclera due to excess bilirubin
which vitamins are stored in the liver? [3]
A, D & B12
explain urea cycle xx
where does it occur? [2]
when is ketone metabolism triggered? [1] & turned off? [1]
how does it occur?
Ketones are an alternative to glucose
Their synthesis is turned on by starvation, turned off by insulin
The point of this is to provide a constant supply of energy to the brain.
Lipids broken down -> ketone bodies -> brain -> A-CoA in the brain
This keeps the brains metabolic pathways running.
how does lipolysis work ?
triglycerides –> 3xFA chains and glycerol via lipase
Fatty acid metabolism
Once triglycerides are broken down to FA, the FA is attached to albumin straight away bc FA in blood is toxic. goes to liver or muscle:
- FA -> Fatty A-CoA (on outer mitochondrial membrane) by acyl CoA synthase
- Fatty A CoA -> mitochondrial matrix by the carnitine shuttle. enzyme carnitine acyl- transferase (CATI)
- Beta oxidation of fatty: A-CoA -> A-CoA + NADH/FADH2 -> Krebs cycle and ETC respectively
net ATP from FA breakdown?
NET = 129 ATP
B-oxidation occurs in all tissues other than? [2]
B-oxidation occurs in all tissues other than:
Brain - risk of oxidative stress form super oxides.
RBC - no mitochondria.
explain the process of lipogenesis
what is the role of Malonyl CoA?
Glucose -> pyruvate -> citrate -> ACoA -> Malonyl CoA -> > complex fatty acids.
Malonyl CoA is a 2C elongator.
regulating step of lipogenesis?
Regulating step:
ACoA – acetyl CoA carboxylase (ACC) –> malonyl-CoA
when are ketones produced? [1]
which 3 ketones are produced in liver by FA breakdown?
Three ketones produced in liver from FA breakdown. Created via ketogenesis from A-CoA, ONLY IN LIVER.
3 main ketones:
(Acetone)- only in small amounts
Acetoacetate
3-Hydroxybutyric acid -
what is overall ketogensis?
which is rate limiting step?
Triglycerides –lipolysis-> Fatty acids -B-ox.-> A-CoA -ketogenesis–> Ketone bodies.
The rate limiting step is catalysed by HMG synthase
