Cyanide Toxicity and Thiamin Deficiency Quiz

A type of phytoalexin produced by plants in the Brassicaceae family, including common vegetables like Brussels sprouts and cabbage. These compounds have a bitter taste and provide defense mechanisms for the plants.

The breakdown products of glucosinolates, formed through enzymatic hydrolysis by myrosinase. These products include thiocyanates, isothiocyanates (ITCs), and cyanogens. ITCs are known for their anti-carcinogenic effects at low to moderate doses.

An enzyme found in plants that hydrolyzes glucosinolates, releasing their breakdown products. Myrosinase can be activated by cutting or chewing the plant, but is deactivated by heat.

A group of compounds that have a goitrogenic effect, meaning they can interfere with iodine uptake by the thyroid gland. This can lead to an enlarged thyroid gland, known as goiter.

A group of sulfur-containing compounds with anti-carcinogenic effects at low doses. They are major breakdown products of glucosinolates and are released by myrosinase.

The process by which glucosinolates are broken down into their various products. It involves enzymatic hydrolysis by myrosinase, followed by spontaneous rearrangements.

A type of compound found in glucosinolate breakdown products. They are known for their toxicity, but are typically found in limited amounts.

The principle of 'the dose makes the poison' applies to glucosinolate breakdown products, particularly ITCs. At low to moderate doses, they have anti-carcinogenic effects, but at high doses, they can become pro-carcinogenic.

A medical condition caused by chronic exposure to cyanide in small doses over time, primarily affecting the peripheral nerves and leading to demyelination.

A form of vision impairment caused by chronic cyanide exposure, leading to damage of the optic nerve.

The process of converting cyanide to a non-toxic form by the enzyme Rhodanese. It involves the transfer of a sulfur atom from a donor molecule to a cyanide molecule.

A type of cyanide intoxication that occurs in the presence of a functional ETC, but where cytochrome a3 has been saturated with cyanide. This saturation leads to decreased oxygen utilization and cellular hypoxia.

The form of iron found in the heme group of methemoglobin, where the iron ion is in the Fe3+ state.

The principle that the effect of a substance depends on the dose.

The ability of a substance to bind to a receptor and block the effect of another substance, like PAH.

The ability of a substance to bind to an enzyme and block its activity.

An enzyme found in certain foods that breaks down thiamin, a crucial vitamin for energy metabolism.

A deficiency of thiamin (vitamin B1), leading to impaired energy production and nerve function.

A serious condition caused by thiamin deficiency, characterized by muscle weakness, fatigue, and nervous system damage.

A syndrome associated with chronic alcohol consumption, characterized by thiamin deficiency and neurological damage.

A form of thiamin (vitamin B1) essential for energy metabolism, particularly involved in the conversion of pyruvate to acetyl CoA.

Phase II metabolic enzymes play a critical role in detoxification by converting harmful substances into more readily excretable forms. These enzymes are often induced by exposure to various compounds, including dietary isothiocyanates, through activation of the AhR pathway.

Isothiocyanates are a group of sulfur-containing compounds naturally found in cruciferous vegetables like broccoli, cauliflower, and Brussels sprouts. While most isothiocyanates aren't metabolized by P450 enzymes, they can still bind to AhR.

Glutathione conjugation is a major pathway for isothiocyanate detoxification. Glutathione, an antioxidant, attaches to the isothiocyanate molecule, making it more water-soluble and easier to eliminate from the body.

Indole-3-carbinol (I3C) is a breakdown product of the glucosinolate glucobarassican. I3C is unstable and quickly dimerizes to form diindolylmethane (DIM), which is responsible for I3C's biological activity.

Sulforaphane is an isothiocyanate formed from the breakdown of the glucosinolate glucoraphanin. It has been shown to have protective effects against cancer development in animal models.

Phenethyl isothiocyanate (PEITC) is an isothiocyanate produced from the breakdown of the glucosinolate gluconasturtiin. Like other isothiocyanates, PEITC has shown promise in reducing cancer incidence in animal studies.

Isothiocyanates, like I3C, sulforaphane, and PEITC, have been shown to reduce cancer risk in animal studies. However, more research is needed to confirm their effectiveness in human studies.

The link between isothiocyanate consumption and reduced cancer risk in humans is still being investigated. While studies have shown potential benefits, more research is needed to confirm their effectiveness in humans.

Naturally occurring toxins found in plants of the nightshade family (Solanaceae), including potatoes, tomatoes, and eggplants.

The most abundant glycoalkaloid in potatoes, responsible for its bitter taste. It's toxic and acts as a natural pesticide for the plant.

Found in tomatoes, especially in green, unripe fruit, and has fungicidal properties. It's also toxic, though lower in ripened tomatoes.

Another glycoalkaloid in potatoes, the second most toxic after solanine.

Glycoalkaloid levels are typically highest in the potato skin, reflecting their role in protecting the plant. Peeling potatoes significantly reduces their content.

Factors such as disease resistance breeding, pest damage, frost, and even harvest injuries can increase glycoalkaloid levels in potatoes.

Cooking, except deep frying, does not significantly affect glycoalkaloid levels. While they are not well absorbed in the gut, they are effectively excreted by the body.

Glycoalkaloids have a wide range of biological activities including anti-inflammatory and anti-cancer effects. However, at higher levels, they can be toxic.