Vitamins & Minerals Online Quiz

Iron is an essential mineral that plays a key role in oxygen transport as part of hemoglobin and in the production of red blood cells and various enzymes. However, it does not directly aid digestion, which is primarily the role of digestive enzymes, stomach acid, and dietary fiber. Therefore, aiding digestion is not a function of iron.

Transferrin is the main glycoprotein in the blood that binds to iron and transports it throughout the body. Ferritin, on the other hand, is primarily a storage protein that keeps iron safely stored inside cells. Therefore, transferrin is the correct protein for bloodstream transport.

Calcium absorption in the small intestine occurs primarily via active transport, especially when dietary calcium levels are low or moderate. This process is highly regulated by active vitamin D (calcitriol). While passive diffusion also occurs when calcium levels are very high, active transport is the primary physiological mechanism for carrying calcium into the bloodstream under normal conditions.

Vitamin C (ascorbic acid) is a crucial cofactor for the enzymes that hydroxylate proline and lysine residues in procollagen, which is essential for the synthesis of stable collagen. Without Vitamin C, collagen fibers cannot form properly, leading to scurvy. Red blood cell production relies more heavily on iron, folate, and vitamin B12.

Most nutrient absorption, including water-soluble vitamins like Vitamin C, takes place in the small intestine. Specifically, Vitamin C is absorbed across the buccal mucosa and mainly in the small intestine via active transport. The large intestine is primarily responsible for water and electrolyte absorption.

Ascorbic acid acts as an antioxidant by donating electrons, which results in its own oxidation. During this metabolic process, it is oxidized to form dehydroascorbic acid. Reduction would involve gaining electrons, which is the reverse of this process.

Vitamin C is chemically known as L-ascorbic acid. Glycogen and glucose are carbohydrates, while glycerol is a component of lipids.

Vitamin K is a critical cofactor for the carboxylation of glutamic acid residues in several blood-clotting proteins, such as prothrombin. A deficiency in Vitamin K leads to impaired blood coagulation, resulting in excessive bleeding. It does not directly impair the nervous or digestive systems.

Vitamin K is a fat-soluble vitamin, meaning it requires dietary fats to be dissolved and properly absorbed. Like most other fat-soluble nutrients, this absorption process occurs in the small intestine with the help of bile salts. Dietary fiber is not absorbed and does not dissolve fat-soluble vitamins.

Vitamin K1 is chemically known as phylloquinone, which is synthesized by plants. Keratin is a structural protein, while glucose and glycogen are carbohydrates.

Minerals are inorganic substances because they do not contain carbon-hydrogen bonds and originate from non-living sources like soil and water. Organic compounds, by contrast, are carbon-based molecules typically produced by living organisms.

Vitamins are organic compounds because they contain carbon and are synthesized by living organisms (plants or animals). This distinguishes them from minerals, which are inorganic elements.