Lipids, Fats, and Biochemistry

Fats (lipids) are stored in cells in the form of triglycerides, which are composed of three fatty acids attached to a glycerol backbone. Polypeptides are protein chains, polysaccharides are complex carbohydrates, nucleosides are DNA/RNA components, and monosaccharides are simple sugars - none of these are fat storage forms.

Vaucheria stores its food reserves primarily in the form of oil droplets within its cytoplasm. This distinguishes it from many other algae that typically store carbohydrates as starch.

Phospholipids are the most abundant lipid class in blood plasma. They form the structural backbone of all lipoprotein particles (HDL, LDL, VLDL, chylomicrons) that transport lipids through the bloodstream. The amphipathic nature of phospholipids allows them to form stable spherical micelles that carry hydrophobic lipids in the aqueous blood plasma.

Fats are lipids that are soluble in organic solvents like alcohol, ether, and chloroform due to their nonpolar nature. The polar nature of water makes it incompatible with hydrophobic fat molecules, which is why fats and oils do not mix with water. Alcohol (ethanol) can dissolve fats because it has both polar and nonpolar regions, allowing it to interact with lipid molecules. This property is exploited in various extraction and purification processes.

Fibrates are actually better absorbed WITH food to enhance bioavailability and reduce GI side effects. The statement claiming better absorption on empty stomach is false. Fibrates activate PPAR-alpha, increase lipoprotein lipase activity, and are indeed first-line for type III hyperlipidemia and hypertriglyceridemia.

These are membrane derived second messengers. They play crucial roles in diverse cellular functions such as cell growth, apoptosis, cell migration, endocytosis, and cell differentiation.

Insulin is a protein hormone (polypeptide) secreted by the beta cells of pancreatic islets of Langerhans. Steroids include hormones like cortisol and testosterone, while lipids and carbohydrates are nutrient classes, not hormone types.

Amylase is a digestive enzyme that specifically breaks down starch into simpler sugars like maltose. It acts on carbohydrates, not lipids or oils. Glucose is a simple sugar that doesn't require enzymatic breakdown.

Saturated fats are popular with manufacturers of processed foods because they are less vulnerable to rancidity and are in general, more solid at room temperature than unsaturated fats.

Palmitoleic acid is a common constituent of the glycerides of human adipose tissue. It is present in all tissues but, in general, found in higher concentrations in the liver. It has been shown to increase insulin sensitivity by suppressing inflammation, as well as inhibit the destruction of insulin-secreting pancreatic beta cells.

This pigment is yellow to orange in colour. It is present in the stratum corneum and fat cells of dermis and superficial fascia.

Eicosapentaenoic acid is an omega-3 fatty acid. It is obtained in the human diet by eating oily fish or fish oil, e.g. cod liver, herring, mackerel, salmon, menhaden and sardine and various types of edible seaweed. It is also found in the human breast milk.

Rumenic acid is a conjugated linoleic acid found in the fat of ruminants and in dairy products. It is an omega-7 trans fat.

Polyketides are synthesised by polymerisation of acetyl and propionyl subunits by classic enzymes as well as iterative and multimodular enzymes that share mechanistic features with the fatty acid synthases. Many commonly used anti-microbial, anti-parasitic and anti-cancer agents are polyketides.

LDL particles are sometimes referred to as bad lipoproteins because they correlate with atherosclerosis progression.