Lipids, Fats, and Biochemistry

Butyric acid (butanoic acid) is naturally present in butter and gives it its characteristic flavor. It's a 4-carbon fatty acid formed from butterfat breakdown. The name itself comes from the Latin word for butter - 'butyrum'. Succinic, oxalic, and maleic acids are not characteristic components of butter.

Horns, nails, and hair are all made of keratin, a tough, fibrous structural protein. Keratin is insoluble in water and organic solvents. It is NOT a fat, carbohydrate, or lipid.

Fungi is the correct answer because penicillin was first discovered in the Penicillium fungi (mold) by Alexander Fleming. It is not obtained from algae, synthetic substances, or synthetic oil. Most antibiotics are derived from fungi or bacteria, though some synthetic versions exist now.

Chicken eggs contain cholesterol, primarily in the yolk - one large egg has about 186 mg of cholesterol. While eggs also contain proteins (in the white) and trace fats, cholesterol is the fatty substance specifically associated with egg yolk and health discussions.

Carbohydrates are the body's preferred and most efficient energy source, broken down into glucose for cellular energy. While fats and proteins also provide energy, carbohydrates are metabolized first and most readily. The term 'favorite' indicates the body's preference for carbs as its primary fuel.

Proteins serve as the primary structural components of the body, forming muscles, bones, skin, and cell membranes. Unlike carbohydrates and fats which mainly provide energy, proteins build and repair tissues. Collagen, a protein, is the most abundant structural protein in the body.

Trans fats are created when liquid oils undergo hydrogenation to become solid fats. The term 'hydrogenated' or 'partially hydrogenated' on ingredient labels directly indicates the presence of trans fats, as this industrial process creates them. Triglycerides are present in all fats, while essential fatty acids refer to healthy fats like omega-3 and omega-6.

Omega-3 fatty acids, particularly EPA and DHA from fatty fish, have been shown to lower blood pressure, reduce LDL cholesterol, and significantly decrease triglyceride levels. All three effects are well-documented benefits of omega-3 consumption, making 'All of the above' correct.

HDL (good) cholesterol should be ABOVE 40 mg/dL for men and 50 mg/dL for women to protect against heart disease. An HDL level of 30 is too low and indicates increased cardiovascular risk. Total cholesterol of 180 is healthy, and LDL of 30 is excellent.

Carbohydrates, proteins, and fats are macronutrients because the body needs them in large amounts (grams) daily. They provide energy (calories): carbs and proteins provide 4 calories/gram, fats provide 9 calories/gram. Micronutrients (vitamins and minerals) are needed in smaller amounts (milligrams/micrograms).

Cholesterol is a major risk factor for heart attacks as it can build up in arteries, forming plaques that restrict blood flow. While not the sole cause, high cholesterol significantly increases cardiovascular risk. The other options (protein, carbon, aluminium) are not directly linked to heart attack risk in the same way.

Many lipsticks contain pearlescent ingredients like guanine, derived from fish scales (specifically herring and sardine scales). This creates the shimmery, iridescent effect in the product. The scales are processed into crystalline guanine powder. Other listed ingredients (peanut oil, apple juice, cotton seeds) are not standard shimmer sources.

Chicken eggs contain cholesterol, a fatty substance found in animal cell membranes. A single egg yolk contains about 185-200 mg of cholesterol. The white (albumen) is primarily protein and water, while the yolk contains fats including cholesterol.