Lipids Flashcards
What are the 3 major classes of lipids stating examples.
- simple (fats like triglycerides, waxes)
- compllex (ex: phospholipids, sphingolipids/glycolipids, lipoproteins)
- derived (ex: fatty acids, glycelrol, steroids, ketone bodies)
What is a complex lipid?
An ester of a fatty acid containing an alcohol, fatty acid, and other groups.
Define a simple lipid.
An ester of a fatty acid which upon hydrolysis yields an alcohol (usually glycerol) and fatty acid(s)
State the 5 types of lipoprotein complexes in the human body.
- LDL
- VLDL
- HDL
- Chylomicrons
- IDL (intermediate density lipoproteins)
What is an apolipoprotein?
The protein that binds to lipids on the lipoprotein complex membrane.
State 3 components of the lipoprotein complex membrane.
apolipoproteins
cholesterol
phospholipids
Prostaglandins are produced from which unsaturated fatty acid?
Arachidonic acid
4 symptoms of essential fatty acids (EFAs) include
- intellectual disability in children
- thromocytopenia (poor wound healing)
- alopecia (hair loss due to autoimmune attack)
- phrynoderma (toad skin)
Which saturated fatty acid contributes least to fat storage?
Lauric acid
Which phospholipid is only found in mitochondria?
Phosphatidic acid
Why is phosphatidic acid essential to mitochondrial functioning?
It is a precursor of phosphatidyl glycerol which is also a precursor of cardiolipin. Low levels of cardiolipin result in mitochondrial disfunction; heart failure, hypothyroidism, and Cardioskeletal myopathy
What is the function of phosphatidyl inositol?
Involved in second messenger system in cell signaling; by cleaving into DAG and IP3
What is the most abundant phospholipid on the cell membrane?
Phosphatidyl choline
State 3 functions of sphingomyelin.
- Cytokinesis (contains domains for binding actin filaments to contract cell)
- Apoptosis (hydrolysis signals cell death)
- Affects cholestrol distribution on plasma membrane (as it forms strong bonds with cholestrol)
Which sphingolipid is the most abundant in myelin sheath?
Cerebrosides
How are cerebrosides involved in Gaucher’s disease?
Caused by excess deposition of glucocerebrosides on myelin sheath and in phagocytic cells, due to lack or malfunction of the enzyme; glucocerebrosidase
What is Gaucher’s disease?
Autosomal recessive condition in which glucocerebrosidase is deficient causing accumulation of glucocerebrosides on myelin sheaths and in phagocytic cells
Which sphingolipid is involved in formation of blood groups ABO?
Gangliocides
Which molecule is the precursor of steroids?
cholesterol
State 3 functions of steroids.
- regulate metabolism
- immune response
- reproduction
Which cells in the body don’t contain cholesterol?
Nervous tissue
