Definitions and Functions
This property characterizes lipids, meaning they are insoluble in water but soluble in non-polar organic solvents.
What is hydrophobic?
Lipids made only of glycerol and three fatty acids, serving as the primary form of energy storage.
What are Triacylglycerols (TAGs)?
The physical state of most unsaturated fatty acids due to the loose packing caused by their cis-double bond kinks.
What is liquid (oils)?
The major site of dietary lipid digestion and absorption.
What is the small intestine?
Pigments found in plants (e.g., beta-carotene).
What are Carotenoids?
A patient with a severe gallbladder obstruction would have trouble digesting a meal rich in fats. The specific step of lipid digestion most inhibited would be this physical breakdown process.
What is emulsification?
A Triacylglycerol molecule's main function, yielding the highest energy upon oxidation.
What is energy storage?
The specific type of lipid that contains a carbohydrate moiety but no phosphate group, often found in nervous tissue.
What are glycolipids?
The specific chemical reaction using an alkali (base) to hydrolyze a fat, yielding glycerol and soap.
What is saponification?
The substance secreted by the gallbladder that emulsifies large fat globules, dramatically increasing their surface area.
What are bile salts (or bile)?
The specific cellular compartment where beta-oxidation of fatty acids occurs.
What are the mitochondria (or mitochondrial matrix)?
During a prolonged 48-hour fast, a patient's liver produces a large excess of Acetyl-CoA from beta-oxidation. This pathway will be initiated to supply fuel to the brain.
What is ketogenesis?
The primary structural role of Phospholipids and Cholesterol in a cell.
What is forming the lipid bilayer / biological membranes?
The structural feature of a fatty acid that is the absence of any double bonds in its chain.
What is saturated?
The chemical process of adding H2 across double bonds in oils to convert them into solid fats like margarine.
What is hydrogenation (or hardening)?
The pancreatic protein that binds to both the pancreatic lipase and the emulsion droplet to anchor the enzyme to its substrate.
What is colipase?
A key precursor in steroid synthesis.
What is Squalene?
An industrial baker wants to convert liquid vegetable oil into a solid, stable shortening. They use this chemical reaction which adds hydrogen across the double bonds.
What is hydrogenation?
The fat underneath the skin, which insulates the body from extreme temperatures and helps keep the internal climate under control.
Subcutaneous fat
The complex of lipids and apoproteins that functions in the transport of fats through the bloodstream.
What are lipoproteins?
Unsaturated fatty acids, whether they are free or combined as esters in fats and oils, react with halogens by addition at the double bond(s). The reaction results in the decolorization of the halogen soluÂtion.
What is Halogenation?
The tiny, spherical structures formed by digestion products and bile salts to transport lipids to the enterocyte brush border.
What are micelles?
The breakdown of stored TAGs in adipocytes into glycerol and FFAs, regulated by hormone-sensitive lipase.
What is lipolysis?
This class of lipids, like Prostaglandins and Leukotrienes, perform the function of signaling and regulating, acting as local mediators of inflammation and blood clotting.
What are eicosanoids?
The precursor for all other steroids in the body, which is a crucial membrane component but not oxidized for energy.
What is cholesterol?
The spontaneous oxidative cleavage of double bonds in unsaturated fatty acids, producing volatile aldehydes and ketones with an unpleasant odor.
What is rancidity (or oxidation)?
The large lipoprotein particle assembled in intestinal cells to transport dietary lipids into the lymphatic system.
What are chylomicrons?
The metabolic pathway in the liver that converts excess Acetyl-CoA into Acetoacetate and beta-Hydroxybutyrate during fasting.
What is ketogenesis?