Concepts Of Clinical Biochemistry! Trivia Quiz

Antioxidants are substances that work against the generation and effect of free radicals. Free radicals are unstable molecules that can cause damage to cells and contribute to aging and disease. Antioxidants neutralize free radicals by donating an electron, thus preventing them from causing harm. They help protect the body from oxidative stress and promote overall health and well-being.

Breast-fed newborns generally have higher serum bilirubin concentrations. This is because breast milk contains substances that can increase the production of bilirubin in the baby's body. Additionally, breast milk is easier to digest, leading to more frequent bowel movements, which helps eliminate bilirubin from the body. Therefore, breast-fed newborns may have higher levels of bilirubin in their blood compared to formula-fed newborns.

The most important source of free radicals is the mitochondrial respiratory chain. During the process of oxidative phosphorylation, electrons leak from the electron transport chain, leading to the generation of reactive oxygen species (ROS) such as superoxide anion and hydrogen peroxide. These ROS can cause oxidative damage to cellular components such as DNA, proteins, and lipids, leading to various pathological conditions. Neutrophils and monocytes-macrophages can also produce free radicals as part of their immune response, but the mitochondrial respiratory chain is considered the primary source of free radicals in the cell. Xenobiotic detoxification is not a significant source of free radicals.

Oxygen commonly accepts two electrons. In its neutral state, oxygen has an atomic number of 8, meaning it has 8 protons and 8 electrons, with 6 electrons in its outermost shell. To complete its octet configuration and achieve a stable electron configuration, oxygen tends to gain two electrons, resulting in a -2 oxidation state. This electron acceptance behavior is essential in various chemical reactions and plays a significant role in oxidation-reduction reactions.

The statement is false. Free radicals actually contain unpaired electrons in the bonding orbital, not paired electrons. This makes them highly reactive and unstable.

Fatty acids are most prone to radical reactions in lipids. This is because they contain a long hydrocarbon chain, which makes them susceptible to oxidation and free radical attacks. The presence of double bonds in unsaturated fatty acids further increases their reactivity towards radicals. Radicals can cause lipid peroxidation, leading to the production of harmful byproducts and damage to cell membranes. In contrast, waxes, vitamins, and hormones do not typically contain long hydrocarbon chains or unsaturated bonds, making them less susceptible to radical reactions.

The specific role of inflammatory reaction is the respiratory burst of phagocytes. During inflammation, phagocytes release reactive oxygen species (ROS) through a process called respiratory burst. This burst helps phagocytes to kill and eliminate pathogens, such as bacteria and fungi, by damaging their cell membranes. The release of ROS is an important defense mechanism of the immune system during an inflammatory response.

Nitric oxide is generated from L-arginine. L-arginine is converted into nitric oxide through the action of the enzyme NO synthase. Nitric oxide is produced by various cells in the body, including neurons and endothelial cells. It plays a crucial role in regulating various physiological processes such as vasodilation, neurotransmission, and immune response.

Hydrophobicity refers to the tendency of a molecule to repel or avoid water. It does not directly refer to the effect of oxidative stress on the structure of biologically important compounds. Oxidative stress can cause fragmentation, cross-linking, and aggregation of these compounds, leading to structural damage and functional impairment.

Selenium is not an example of hydrophilic because it is a nonpolar element that does not readily dissolve in water or interact with water molecules. Hydrophilic substances, on the other hand, have an affinity for water and are capable of forming hydrogen bonds with water molecules. Thiols, uric acid, and ferritin are examples of hydrophilic substances as they can dissolve or interact with water.