Biochemistry Vitamins and Minerals Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary source of vitamin D for humans?

Dietary sources

Liver

Kidney

Skin synthesis (correct)

What is the function of 25-hydroxycholecalciferol in the liver?

Hydroxylation of cholecalciferol (correct)

Regulation of calcium absorption

Synthesis of vitamin D

Storage of vitamin D

What is the main function of vitamin D in the body?

Energy production

Protein synthesis

Antioxidant function

Regulation of calcium absorption (correct)

What is the active form of vitamin D produced in the kidney?

1,25-dihydroxycholecalciferol Signup and view all the answers

What is the result of vitamin D deficiency in adults?

Osteomalacia Signup and view all the answers

What is the primary function of vitamin E?

Antioxidant function Signup and view all the answers

What is the most active form of vitamin E?

D-α-tocopherol Signup and view all the answers

What is the consequence of taking excessive vitamin D supplements?

Hypervitaminosis D Signup and view all the answers

What is biochemistry primarily concerned with?

The chemical reactions in living organisms Signup and view all the answers

Which nutrient category do vitamins fall under?

Organic nutrients required in small quantities Signup and view all the answers

How do vitamins typically function in biochemical processes?

As catalysts by combining with proteins Signup and view all the answers

What must be supplied by the diet since the body generally cannot synthesize them?

Vitamins and certain amino acids Signup and view all the answers

Which of the following roles do vitamins NOT play in the body?

Building structural proteins for muscle Signup and view all the answers

What is the significance of vitamins in relation to enzymes?

Vitamins help create metabolically active enzymes Signup and view all the answers

What is the primary difference between water-soluble and fat-soluble vitamins?

Water-soluble vitamins are excreted, while fat-soluble vitamins are not. Signup and view all the answers

Which of the following is NOT a function of vitamin A?

Production of insulin Signup and view all the answers

What is the difference between retinoids and carotenoids?

Retinoids are preformed vitamin A, while carotenoids are provitamin A. Signup and view all the answers

Which of the following is a potential consequence of chronic vitamin A toxicity?

Hepatomegaly Signup and view all the answers

What is the recommended upper limit of vitamin A intake for women who are pregnant or may become pregnant?

3000 micrograms Signup and view all the answers

Which of the following is a common sign of vitamin A deficiency?

Night blindness Signup and view all the answers

What is the most important role of retinoic acid in the body?

Regulation of gene expression Signup and view all the answers

What is the main difference between the treatment for water-soluble and fat-soluble vitamin deficiencies?

Water-soluble vitamin deficiencies require regular dietary supply, while fat-soluble vitamin deficiencies require a single large dose. Signup and view all the answers

Study Notes

Biochemistry

Biochemistry is the science concerned with the study of chemical reactions that occur in living organisms.

Vitamins

Vitamins are organic nutrients required in small quantities for various biochemical functions and cannot be synthesized in the body.
Vitamins assist in the formation of hormones, blood vessels, nervous system chemicals, and genetic materials.
Vitamins act as catalysts, combining with proteins to create metabolically active enzymes essential for life reactions.

Classification of Vitamins

Vitamins can be classified into water-soluble and fat-soluble vitamins.

Water-Soluble vs Fat-Soluble Vitamins

Water-soluble vitamins:
- Are soluble in water
- Are absorbed simply
- Are not stored in the body
- Are excreted
- Excess intake is non-toxic
- Deficiency manifests rapidly
- Treatment involves regular dietary supply
Fat-soluble vitamins:
- Are soluble in fat
- Are absorbed along with lipids
- Are stored in the liver
- Are not excreted
- Excess intake is toxic
- Deficiency manifests slowly
- Treatment involves a single large dose

Fat-Soluble Vitamins: Vitamin A

Vitamin A occurs in two forms in food: retinoids and carotenoids.
Retinoids are preformed vitamin A found only in foods of animal origin.
Carotenoids are found in plants, comprise carotenes and related compounds, and are known as provitamin A.
Vitamin A functions include:
- Vision
- Antioxidant activity
- Regulation of gene expression and tissue differentiation
- Essential for health and growth
- Essential for bone formation and calcification
- Gene regulation during early fetal development
Vitamin A toxicity can occur with doses above 200 mg of retinol or retinal, or chronic consumption of more than 40 mg/day, causing symptoms such as gastrointestinal issues, neurological symptoms, dermatological symptoms, and musculoskeletal issues.
Vitamin A deficiency can cause night blindness, xerophthalmia, infections, keratinization of skin, and impairment of immune responses.

Fat-Soluble Vitamins: Vitamin D

Vitamin D is not strictly a vitamin since it can be synthesized in the skin, and under most conditions, that is its major source.
Vitamin D is present in two forms: ergocalciferol (vitamin D2) found in plants and cholecalciferol (vitamin D3) found in animal tissues.
Vitamin D is present in only a few natural foodstuffs, including liver, egg yolk, and saltwater fish.
The main function of vitamin D is in the regulation of calcium absorption.
Vitamin D is synthesized in the skin by the action of ultraviolet radiation, and then hydroxylated to 25-hydroxycholecalciferol in the liver and further hydroxylated to 1,25-dihydroxycholecalciferol (calcitriol) in the kidney.
Vitamin D deficiency can cause rickets in children, osteomalacia in adults, and osteoporosis.
Vitamin D toxicity, caused by overuse of supplements, leads to hypercalciuria and metastatic calcification (abnormal calcification of soft tissues).
Symptoms of vitamin D toxicity include anorexia, weight loss, irregular heart beat, and hardening of blood vessels and tissues due to increased blood levels of calcium.

Fat-Soluble Vitamins: Vitamin E

Vitamin E is the generic descriptor for two families of compounds: the tocopherols and the tocotrienols.
The most active form is D-α-tocopherol.
The main function of vitamin E is as a chain-breaking, free radical-trapping antioxidant in cell membranes and plasma lipoproteins.
Vitamin E is an antioxidant and scavenger of free radicals, protecting membranes, fat depots, and lipoprotein from lipid peroxidation.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge of biochemistry, vitamins, and minerals. This quiz covers various aspects of biochemistry, including vitamins and minerals like Na, Mg, Fe, and Ca.