Lipids, Fats, and Biochemistry

The plasma membrane is primarily composed of a phospholipid bilayer, which provides the structure and selective permeability of the cell.

Essential nutrients are defined as those that the body cannot synthesize on its own in sufficient quantities and must therefore be obtained through the diet.

The energy in food (and oil) is stored in the chemical bonds of the molecules. When these bonds are broken during digestion or combustion, energy is released.

Before DNA was confirmed as the genetic material, scientists believed proteins were the carriers of genetic information because of their structural complexity and the variety of their 20 amino acid building blocks.

Unsaturated fats, found in vegetable oils, nuts, and seeds, are beneficial for heart health when consumed in moderation. In contrast, saturated and trans fats can increase cholesterol levels and the risk of heart disease. Therefore, dietary guidelines recommend choosing unsaturated oils over solid fats.

Health organizations recommend limiting saturated fat intake because high consumption is linked to increased LDL cholesterol levels and a higher risk of cardiovascular disease. Unsaturated fats and essential fatty acids are considered healthier fats.

Villi absorb monomers and small molecules such as amino acids, fatty acids, mineral ions, and vitamins. Large macromolecules like intact proteins cannot be absorbed by the villi and must first be digested into amino acids.

Fat is the most energy-dense macronutrient, providing 9 kilocalories (kcal) of energy per gram. In comparison, carbohydrates and proteins provide only 4 kcal per gram, while alcohol provides 7 kcal per gram.

Triglycerides, which make up most dietary fats, consist of three fatty acid molecules bound to a single backbone molecule of glycerol. Glucose and galactose are simple sugars, while gelatine is a protein derived from collagen.

Oily fish such as salmon, mackerel, and sardines are excellent sources of omega-3 fatty acids, which are essential fatty acids. Since the human body cannot produce these fats on its own, they must be obtained through our diet.

Fat is classified as a macronutrient because the body requires it in relatively large quantities to provide energy and support cellular functions. Micronutrients, on the other hand, are vitamins and minerals that the body needs only in very small amounts.

Collagen is the most abundant protein in the animal kingdom and is a fibrous structural protein. It provides strength and structural support to various connective tissues like skin, tendons, and ligaments.

Proteins are large, nitrogenous organic compounds made up of long chains of amino acids. Carbohydrates and fats are also organic compounds, but they do not contain nitrogen as a defining structural element.

Fats are organic molecules that serve as a concentrated energy source and are stored as oily or greasy substances in animal bodies. Unlike proteins or rations, fats are primarily composed of lipids.

Fats are a highly concentrated source of energy, providing more than twice the energy per gram compared to carbohydrates or proteins. Additionally, fat deposits in the body serve as thermal insulation to help regulate body temperature and protect internal organs.