Lipids, Fats, and Biochemistry

They are membrane proteins present in plasma membrane. About 70% to 80% of membrane proteins are integral proteins. These are not easily extracted from membrane. Integral proteins are amphipathic. Their hydrophobic regions are buried in the lipid while the hydrophilic portions project from the membrane surface.

Collagen is the major insoluble fibrous protein in the extracellular matrix and in connective tissue. In fact, it is the single most abundant protein in the animal kingdom. Collagen, in the form of elongated fibrils, is mostly found in fibrous tissues such as tendon, ligament, and skin and is also abundant in cornea, cartilage, bone, blood vessels, the gut, and intervertebral disc. The fibroblast is the most common cell, which creates collagen.

The hydrocarbon tails of these two lipids result in steric limitations to their packing such that they will form disc-like micelles. The structure of these micelles results from the interaction of the hydrophobic tails of the lipids and the exposure of the polar head groups to the aqueous environment. Glycerophospholipids have a glycerol backbone. Phosphtidylinositol is an example for glycerophospholipids. Sphingolipids are derivatives of the lipid sphingosine. Cerebroside is an example for sphingolipids.

Fats are broken down during digestion into glycerol and fatty acids. Glycerol is the backbone of fat molecules. Proteins digest into amino acids, and carbohydrates like starch break down into simple sugars like glucose or fructose.

This option is correct because bioten is called vitamin H, which is completely soluble in water.

The correct order is d > a > b > c.

This is the correct option.

Proteins are composed of amino acids linked together by peptide bonds. There are 20 standard amino acids that combine in various sequences to form different proteins. Carbohydrates are made of sugar units, fats of fatty acids and glycerol, while minerals are inorganic elements.

Vegetable oils like olive, sunflower, and canola oil contain primarily unsaturated fats, which are liquid at room temperature. Milk, cheese, and coconut oil are high in saturated fats. Unsaturated fats are generally considered healthier for cardiovascular health.

Adipose tissue is specialized connective tissue designed to store fat in the form of triglycerides. It serves as the body's primary energy reserve. Roughage (fiber) aids digestion, vitamins are organic compounds needed in small amounts, and minerals are inorganic elements.

Blood clotting is primarily the function of platelets and clotting factors, not fats. Fats provide concentrated energy, support brain development (especially omega-3 fatty acids), and serve as precursors for hormone synthesis. Blood clotting mechanisms involve proteins like fibrinogen, not lipids.

Fats act as an insulator and prevent the loss of heat from the animal body.

The plasma membrane (cell membrane) has a fluid mosaic structure composed of phospholipids (lipids), embedded proteins, and carbohydrates attached to proteins (glycoproteins) and lipids (glycolipids). These carbohydrates form the glycocalyx on the cell surface and are important for cell recognition.

Fats yield the highest energy per gram.

This is the correct option. Smooth ER does not play an important role in the biosynthesis of polysaccharides.