Bile and Plasma Lipids Flashcards
What is a phospholipid?
A lipid based molecule which has a polar head and hydrophobic trail regions
What is glycolysis?
The breakdown of glucose into pyruvate
What is gluconeogenesis?
Glucose generation from non-carbohydrate carbon substrates such as pyruvate
What is glycogenolysis?
The breakdown of glycogen into glucose
What is lipolysis?
The breakdown of lipids, from triglycerides to free fatty acids and glycerol
What are ketone bodies?
Type of lipid based energy molecule produced when the body lacks glucose for energy
Given the hydrophobicity of fats, how are they transported around the body?
As lipoproteins
Lipoproteins are transported via two pathways.. What are they?
Exogenous and Endogenous Pathway
The exogenous pathway transports what… from where to where…?
Dietary lipids from the intestine to tissues
The endogenous pathway transports what… from where to where…?
Endogenous TGs and cholesterol from the liver to tissues
What are names of the four types of Lipoprotein
Chylomicrons
VLDLs
LDLs
HDLs
Of the four lipoproteins, which has the largest size?
Chylomicrons
Of the four lipoproteins, which has the largest density?
HDLs
Of the four lipoproteins, which has the the smallest size?
HDLs
Of the VLDLs and HDLs, which has the the smallest density?
VLDLs
Of the lipoprotein categories, which has the highest lipid %?
Chylomicrons
Of the lipoprotein cateogies, which has the highest protein %?
HDLs
What are the four types of Apoproteins?
A, B, C, E
What is the function of Apoproteins A, B, C, E?
A: Reverse Cholesterol Transport
B: LDL Binding and clearance
C: Regulation of LPL
E: Remnant receptor binding and clearance
LPL is activated by which Apoprotein?
Apoprotein C-II
Give 5 examples of things which can alter your LDL:HDL ratios
- Genetics
- Poor diet
- Poor glucose (T2 Diabetes)
- Lack of exercise
- Central obesity
LPL converts a Chylomicron into…? What is removed?
Chylomicron remnant. Fatty acids and Apo C is removed
A chylomicron remnant has which Apoproteins?
E and B
A chylomicron remnant is picked up the liver through which Apoproteins and which process?
Apo E and B, receptor mediated uptake
The liver packages Chylomicron remnants into…?
VLDLs
LPLs act on which two classes of lipoproprotein?
VLDL and Chylomicrons
VLDL binds to LPL and becomes…?
IDL
IDL binds to… to form an LDL?
Hepatic Lipase
LDL binds to the peripheral tissues by which Apoprotein?
Apo B
What happens when LDL enters the peripheral tissue?
It is picked up by an endosome and broken by lysosome to release free amino acids and cholesterol. The cholesterol is transformed by cholesteryl ester via LCAT. Remaining produces are packaged into HDL
An HDL molecule is picked up by the liver via which apoprotein?
Apoprotein A
What are Xanthoma?
Cholesterol deposits
What are the normal levels of cholesterol?
< 5.0 mmol/L
What is the mechanism of Statins?
Inhibition of HMG-CoA Reductase
What are the two classes of adipose tissue?
White adipose tissue and Brown adipose tissue
What two ways are White Adipose Tissue synthesised?
- Endogenously by glucose and driven by insulin
2. Via breakdown of VLDLs or Chylomicrons via LDLs which release TGs
During a starvation event, the glucose levels dissipate in the brain. What happens?
Fats are converted into ketone bodies in the liver (via b-oxidation and ketogenesis)
What is the difference about the cells in WAT and BAT?
White adipose tissue: One significant droplet
Brown adipose tissue: More droplets and significantly smaller. Has mitochondria and thermogenin channels to generate heat
Outline the process of RBC breakdown
- Haemoglobin is broken down into Heme and Globin
- Heme is then converted to Biliverdin
- Biliverdin is converted to Bilirubin
- Bilirubin binds to Albumin and circulates in the plasma and is picked up by the liver
- The bilirubin undergoes conjugation with glucaronic acid to make it more soluble
- It is then excreted as bile into the bile duct and then intestine
- Once in intestine, can go two ways
7a. Bacteria act on the bile to form urobillinogen to be sent to kidneys for excretion
7b. Or, it can be sent back to the portal circulation
