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Lipids Oral contraceptive:
Oral contraceptive: • Combined oral contraceptive pills were developed to prevent ovulation by suppressing the release of gonadotropins. Combined hormonal contraceptives, including COCPs, inhibit follicular development and prevent ovulation as a primary mechanism of action. High level Estrogen and progesterone insure the that no additional eggs are release from ovarian and follicle not developed (no eggs release in fallopian tube). However, progesterone is effective only when injected. Consequently, synthetic steroids have been prepared that can taken orally and that function in the female body like progesterone such as mestranol, norethynodrel and norethindrone.
Oral contraceptive • Video
Steroids hormones • The natural steroid hormones are generally synthesized from cholesterol in the gonads and adrenal glands. These forms of hormones are lipids. For example Cortisol and testosterone. They have regulatory functions. They release when need in very small amount. They react with specific receptors on target cells or target tissues.
hydrogenation of oilsThis reaction carried on vegetable oil into solid vegetable fat .Such reaction carried for production oleomargarine and cooking oils
There are two disadvantages of using soap 1. they cannot be used in acidic water 2. they cannot used in hard water (Ca &Mg form precipitate ). The precipitate are insoluble soap.
lipoproteins • Lipoproteins: in the body, lipids must be transported through the bloodstream to tissues where they are stored, used for energy, or to make hormones. However, most lipids are nonpolar and insoluble in the aqueous environment of blood. They are made more soluble by combining them with phospholipids and proteins to form water-soluble complexes called lipoproteins.
There are several types of lipoproteins that differ in density, lipid composition, and function: 1. Chylomicrons 2. Very-low-density lipoprotein (VLDL) 3. Low-density lipoprotein (LDL) 4. High-density lipoprotein (HDL).
Cell membrane • In the fluid mosaic model, proteins known as peripheral proteins emerge on just one of the surface, outer or inner. The integral proteins extend through the entire lipid bilayer and appear on both surfaces of membrane. Some carbohydrates are attached to proteins and lipids and they are responsible for cell recognition and communication with chemical messengers such as hormones.
Most membrane contain about 40% lipid and 60% proteins. • A membrane that is a high selective for the kind of molecules or ions that it allow to pass is called semipermeable membrane. In this way , membrane control the composition of the region within cell. • Control flow of information between cell and their surroundings (receptors –proteins molecules).
The cell membrane contains two types of associated proteins. Peripheral membrane proteins are exterior to and connected to the membrane by interactions with other proteins. Integral membrane proteins are inserted into the membrane and most pass through the membrane. Portions of these transmembrane proteins are exposed on both sides of the membrane. Cell membrane proteins have a number of different functions.
Fatty acids, phospholipids, sphingolipids, bile salts, and, to a lesser extent, cholesterol contain polar groups. Therefore, a part of the molecule is hydrophobic, or water insoluble; and a part is hydrophilic, or water soluble. Such molecules are described as amphipathic. They become oriented at oil-water interfaces with the polar group in the water phase and the nonpolar group in the oil phase. A bilayer of such amphipathic lipids is the basic
structure in biologic membranes. When a critical concentration of these lipids is present in an aqueous medium, they form micelles.
