Flashcards in Biochemical Aspects of Liver Metabolism Deck (77)
Where is the first destination of most nutrients and xenobiotics absorbed from the GI tract?
What does the liver produce?
Name a plasma protein excreted from the liver?
What two roles does the liver have in regulation of metabolism?
1. Carbohydrate and lipid metabolism - fuel storage
2. Amino acid metabolism - urea cycle
What allows seperation of proteins by size?
What 4 plasma proteins can be seperated by electrophoresis?
2. Alpha globulins
4. Gamma globulins
What substances maintan oncotic or colloid osmotic pressure?
What transports hydrophobic substances like steroid hormones, free fatty acids, bilirubin and cholesterol?
How can plasma proteins be involved with pH buffering?
Amino-acid side chains can carry net charges
What plasma proteins transport lipoproteins, lipids, hormones and bilirubin?
Alpha-globulins such as ceruloplasmin
What alpha-globulin, other than ceruloplasmin, transports vitamin A?
Retinol binding protein
What does deficiency of vitamin A cause?
What is vitamin A converted to?
Retinaldehyde, part of rhodopsin, a visual pigment
Name two beta-globulins?
Transferrin and fibrinogen
What two things does transferrin do?
Indicator of iron deficiency
What is an inactive form of fibrin and is involved in clotting of blood?
What is the most abundant plasma protein?
How would you describe albumin?
Small, negatively charged, water-soluble
What is the main determinant of plasma oncotic pressure?
What stimulates production of albumin in the liver?
What are levels of albumin like in liver disease?
What two factors can lead to low levels of albumin?
Starvation and low protein diets
What does albumin have multiple binding sites for?
What is the affinity and capacity like for albumin?
Low affinity, but high capacity because of high concentration
Name three endogenous lipophilic substances that albumin transports?
What important exogenous substances does albumin carry?
What special structural feature of albumin allows it to carry hydrophobic molecules?
Hydrophilic clefts in globular domains
What do haemoglobin, myoglobin and cytochromes all haev which is a key component?
How is iron transported?
As ferric ion Fe3+ bound ti transferrin