Lipids, Fats, and Biochemistry

They are the cheapest and most readily available sources of energy. Simple carbohydrates are digested faster and converted into glucose which is used by the body for energy in the blood as glucose or stored in either the muscles or the liver as glycogen. If we eat more carbohydrates than we need for our energy requirements, the excess is converted to fat which is stored in our body.

Phospholipids are phosphorus-containing lipids, such as lecithin and cephalin that are composed mainly of fatty acids, and a phosphate group. Chemically DPL is phospholipid. Phospholipid is the main component of biological membranes.

Fats contain larger proportion of carbon and hydrogen. 

Cream is an example of animal fat.

This is the correct option. Fats give 2.25 times more energy than carbohydrates.

This is the correct option. Fats and carbohydrates are the nutrients that are used by an organism mainly as a source of energy.

Cholesterol comprises 26% of total lipids in the human myelin sheath.

Cholesterol comprises 25% of total lipids in RBC cell membrane.

The meibomian glands or tarsal glands are a special kind of sebaceous gland at the rim of the eyelids inside the tarsal plate responsible for the supply of meibum, which is an oily substance that prevents evaporation of the eye's tear film. Meibum prevents tear spillage onto the cheek, trapping tears between the oiled edge and the eyeball, and makes the closed lids airtight.

Whenever an oil tank leaks, then oil covers the whole of the water surface. This is known as an oil slick.

Sweets, fried foods, butter, and bakery products are all high in fats. Sweets contain fats from butter/oil, fried foods absorb cooking oils, butter is nearly 100% fat, and bakery products use butter/oil. These foods do not contain roughage (fiber), significant proteins, minerals, or vitamins - their primary macronutrient is fat.

Both carbohydrates and fats serve as primary energy sources. Carbohydrates provide quick energy (4 calories/g) while fats provide concentrated sustained energy (9 calories/g). The body uses both for different energy needs depending on activity level and duration.

Chemically all antibodies are proteins.

Plasma membranes of prokaryotes are less rigid because they lack sterols. However,  the prokaryote mycoplasma despite being a prokaryote contains sterols.

Cholesterol is an important sterol found in animal tissues. A sterol is the one in which the steroid nucleus (4 fused rings in which 3 rings have 6 carbons and 1 has 5 carbons) contains one or many hydroxyl groups but no carboxyl or carbonyl groups. It is an important component of plasma lipoproteins and plasma membrane. Cholesterol has a polar hydroxyl group on C-3 and also a hydrocarbon side chain on C-17.