Lecture 6: Lipids Flashcards
What lipids are used for cell membranes?
Phospholipids and cholesterol
What form of lipid is used for energy stores?
Triglycerides
What are steroids and FAs used for?
Regulatory roles as hormones, vitamins and bile acids
How is energy stored in cells in the short term?
ATP
Redox agents
Ionic transmembrane gradients
How is energy stored in cells in the long term?
Carbohydrates and fats
What are the 3 potential uses for acetyl coA?
Cholesterol
Citric acid cycle
Stored energy as FAs
How can acetyl CoA be made?
From glucose or from fatty acids
What forms of energy can be used by the brain?
No glycogen in the brain - only glucose or ketone bodies
What is acetyl CoA added to to make citric acid?
OAA
What is the principle behind the citric acid cycle?
Acetyl coA gets turned into energy by burning O2 and making CO2
What are the uses of cholesterol?
Essential component of cell membranes, precursor of biles acids, steroid hormones and vitamin D
What percentage of plasma cholesterol is esterified?
75%
Name two ketone bodies.
Acetoacetic acid
Beta-hydroxybutyric acid
What is the waste product of making ketone bodies?
Acetone
How are ketone bodies eliminated?
By the kidney
What is the cis angle?
123 degrees
What is the trans angle?
132 degrees
When using omega terminology, do you start from the left or right?
Left
What is the relationship between melting point and double bonds?
Saturated fats more likely to be solid
As increase number of double bonds, the melting point decreased - more likely to be mobilisable - because of the kinks
What are the four lipid transport pathways?
Gut to liver and periphery (exogenous)
Liver to periphery (endogenous)
Periphery to liver (reverse)
Liver to digestive tract (bile acids)
What fat molecule represents the exogenous pathway?
Chylomicrons
What fat molecule represents the endogenous pathway?
VLDL
What fat molecule represents the reverse pathway?
HDL
What are bile acids used for?
Digest fats in the diet
Emulsifies fats
What is lipoprotein lipase used for?
Metabolises TG to FA and glycerol
Where is LPL?
Cell surface
What is apolioprotein?
Protein in lipoprotein particle that can hold lipid
Amphipathic
Which is less dense- protein or lipid?
Lipid
Which particles signify atheroma risk?
VLDL, IDL and LDL
Which pancreatic cells release insulin?
Beta cells
Which pancreatic cells release glucagon?
Alpha cells
Which type of diabetes results from relative insulin deficiency as a result of insulin resistance?
Type 2
How do statins work?
Block HMG-CoA reductase
