Lipids Flashcards
how many classes there are?
There are two classes of lipid-based reproductive hormones, the steroids and the eicosanoids.
Are lipids less soluble in aqueous fluids of the body than are proteins and monoamines?
Lipids are in general less soluble in the aqueous fluids of the body than are proteins and monoamines.
how are they often?
They are often either modified for transport through the body fluid or carried on transporters.
1) Steroids
title
What do steroid hormones comprise/from what are they all derived?
The steroid hormones comprise a large group of molecules all derived from a common sterol precursor: cholesterol.
From what is cholesterol synthesized and what is cholesterol’s role?
Cholesterol is synthesized from acetate in many tissues of the body, and is an important structural component of cell membranes.
what is the first and common step in the formation of all major steroid hormones?
The conversion of cholesterol to pregnenolone marks the first and common step in the formation of all major steroid hormones.
where does the conversion occur?
The conversion occurs on the inner mitochondrial membrane.
where is Pregnenolone then converted?
Pregnenolone is then converted to the sex steroids in the adjacent smooth endoplasmic reticulum.
How many main families of steroids are there?
There are four main families of steroid: the progestagens, androgens, oestrogens and corticosteroids.
What are the first 3 steroids considered as?
The first three steroids are considered as the sex steroids.
How is the interconversion from one class of steroid to another undertaken?
The interconversion from one class of steroid to another is undertaken by a series of enzymes arranged together as a biosynthetic unit.
What do the structural features shared by members of each steroid class give?
The structural features shared by members of each steroid class are reflected in common functional properties.
Androgens
androgens are associated with the development and maintenance of male characteristics and fertility
Oestrogens
oestrogens with the development and maintenance of female characteristics and fertility