1. The right answer is Vitamin D.
Vitamin D is a fat-soluble vitamin (soluble in lipids). It is a hormone found in food and synthesized in the human body from a derivative of cholesterol or ergosterol under the action of UVB1 radiation from the Sun.
In humans, it exists in two forms: D2 (ergocalciferol) produced by plants or D3 (cholecalciferol) of essentially animal origin or synthesized in the skin under the effect of ultraviolet rays. Some plants, especially lichens, also produce the D3 form. These two molecules are 9,10-secosteroids.
2. The right answer is Linoleic acid.
Linoleic acid is a polyunsaturated fatty acid, type omega-6, found in vegetable oils, especially in safflower oil.
It is an essential fatty acid, it must be brought to the body through food.
Its carbon chain consists of 18 carbon atoms, and two double bonds, one involving the sixth carbon, and the other the ninth.
Its melting temperature is -9 ° C, which makes linoleic acid liquid at room temperature.
