VITAMIN B 1 IN DETAIL

Did you know?!

The three foods providing the most Vitamin B1 (thiamine) are:

Pork: Especially lean cuts like pork chops and pork tenderloin.
Sunflower Seeds: Particularly raw or roasted without salt.
Whole Grains and Fortified Cereals: Whole wheat, brown rice, and specially fortified breakfast cereals.

These foods are particularly rich in thiamine and

can significantly contribute to meeting daily dietary requirements.

Certain medications, including diuretics and oral contraceptives, have been found to interfere with the absorption of thiamine, a crucial B vitamin involved in energy metabolism and nerve function.

This interference can lead to an increased risk of thiamine deficiency, potentially causing symptoms such as weakness, nerve damage, and heart problems. Understanding the potential impact of these medications on thiamine absorption is important for healthcare providers to consider when prescribing them, especially for individuals at risk of deficiency due to dietary factors or other medical conditions.

Thiamine deficiency represents a significant health concern, particularly among populations heavily reliant on polished rice or refined grains, where dietary staples lack adequate thiamine content. Furthermore, conditions such as HIV/AIDS, gastrointestinal diseases, and hyperthyroidism can precipitate thiamine deficiency due to heightened metabolic demands or impaired absorption mechanisms. Scientific investigations have explored thiamine supplementation as a potential therapeutic intervention for conditions like Alzheimer's disease, diabetic neuropathy, and congestive heart failure.

Despite promising preliminary findings, further research is warranted to establish its efficacy conclusively.

VITAMIN B 1 THIAMINE

Functions:

Energy Metabolism:

Thiamine plays a crucial role in the conversion of carbohydrates into energy. It is a coenzyme for the enzyme complex pyruvate dehydrogenase, which is involved in the conversion of pyruvate to acetyl-CoA, a critical step in the Krebs cycle (also known as the citric acid cycle or TCA cycle).
It is also a coenzyme for alpha-ketoglutarate dehydrogenase and transketolase, enzymes involved in the Krebs cycle and the pentose phosphate pathway, respectively.

Nervous System Function:

Thiamine is essential for the synthesis of neurotransmitters. It helps in the production of acetylcholine, which is crucial for memory and cognitive function.
It also contributes to the maintenance of myelin sheaths, which insulate nerve fibers and ensure proper nerve signal transmission.

Synthesis of Pentose Phosphate Pathway Intermediates:

Thiamine acts as a cofactor for transketolase, an enzyme involved in the pentose phosphate pathway. This pathway generates pentose sugars and NADPH, which are essential for nucleotide synthesis and protecting cells against oxidative stress.

Amino Acid Metabolism:

Thiamine is involved in the metabolism of certain amino acids, particularly branched-chain amino acids (leucine, isoleucine, and valine). It participates in the decarboxylation reactions that help convert these amino acids into usable metabolic intermediates.

Fatty Acid Metabolism:

Thiamine contributes to the metabolism of fatty acids by serving as a cofactor for alpha-ketoglutarate dehydrogenase, an enzyme involved in the conversion of alpha-ketoglutarate to succinyl-CoA, a step in the Krebs cycle that links carbohydrate and lipid metabolism.

Muscle Function:

Adequate levels of thiamine are necessary for muscle contraction and coordination.

Cardiovascular Health:

Thiamine is important for the proper functioning of the heart and maintaining normal heart rhythm.

Overall, thiamine is indispensable for various biochemical pathways essential for energy production, nerve function, and cellular metabolism. Deficiency in thiamine can impair these processes and lead to a range of health problems, including neurological disorders and energy deficiency.

Food Sources: Thiamine is found in a variety of foods. Here are some rich sources:

Whole Grains: Whole wheat, brown rice, oats, and barley.
Meats: Pork, liver, and other organ meats.
Legumes: Beans, lentils, and peas.
Nuts and Seeds: Sunflower seeds, flaxseeds, and macadamia nuts.
Vegetables: Spinach, kale, and other green leafy vegetables.
Fortified Foods: Some breads, cereals, and pasta products are fortified with thiamine.

Deficiency: A deficiency in thiamine can lead to several health issues, such as:

Beriberi: A condition that can affect the cardiovascular system (wet beriberi) or the nervous system (dry beriberi), leading to symptoms like swelling, heart problems, weakness, and nerve degeneration.
Wernicke-Korsakoff Syndrome: A serious neurological disorder often associated with chronic alcoholism, characterized by confusion, ataxia (loss of coordination), and memory problems.

Daily Requirements: The recommended daily intake of thiamine varies by age, sex, and life stage. For adults, the recommended daily allowance (RDA) is approximately:

Men: 1.2 mg per day
Women: 1.1 mg per day
Pregnant or Breastfeeding Women: 1.4 mg per day

Ensuring a diet rich in thiamine-containing foods is important for maintaining overall health and preventing deficiency-related conditions.

THE KREBS CYCLE

The Krebs cycle, also known as the citric acid cycle or the tricarboxylic acid (TCA) cycle, is a fundamental metabolic pathway occurring in the mitochondria of cells. It is central to the aerobic respiration process, where cells utilize oxygen to generate energy in the form of adenosine triphosphate (ATP) from carbohydrates, fats, and proteins.

Here's a simplified explanation of the Krebs cycle:

Acetyl-CoA Formation:

Before entering the Krebs cycle, molecules derived from carbohydrates, fats, or proteins are broken down into acetyl-CoA. This conversion occurs in the cytoplasm or mitochondrial matrix, depending on the source of the molecules.
Each molecule of acetyl-CoA contains two carbons derived from the breakdown of glucose, fatty acids, or certain amino acids.

Acetyl-CoA Entry into the Cycle:

Acetyl-CoA enters the Krebs cycle by combining with a four-carbon molecule called oxaloacetate, forming a six-carbon compound called citrate. This step is catalyzed by the enzyme citrate synthase.

Series of Reactions:

Through a series of enzymatic reactions, the citrate molecule undergoes a series of transformations, releasing two molecules of carbon dioxide (CO2) and generating energy-rich molecules such as NADH and FADH2.
These energy carriers, NADH and FADH2, carry electrons to the electron transport chain (ETC) embedded in the inner mitochondrial membrane, where they participate in ATP synthesis.

Regeneration of Oxaloacetate:

After several reactions, the remaining four-carbon compound is transformed back into oxaloacetate, thus completing the cycle. Oxaloacetate can then combine with another molecule of acetyl-CoA to continue the cycle.

ATP Production:

Throughout the Krebs cycle, energy-rich molecules NADH and FADH2 are generated. These molecules carry high-energy electrons to the electron transport chain (ETC), where they donate their electrons.
As electrons move through the ETC, they drive the synthesis of ATP through oxidative phosphorylation. This process involves the generation of a proton gradient across the inner mitochondrial membrane, which is used to drive ATP synthesis by the enzyme ATP synthase.

Final Products:

The Krebs cycle produces several ATP molecules directly through substrate-level phosphorylation, as well as NADH and FADH2, which go on to generate more ATP through oxidative phosphorylation in the electron transport chain.

In summary, the Krebs cycle is a vital metabolic pathway that breaks down acetyl-CoA molecules derived from carbohydrates, fats, and proteins to produce ATP and other energy carriers, which are then utilized by the cell for various metabolic processes.

Learn More KREBS CYCLE

REFERENCES

Overview and Functions of Vitamin B1:

National Institutes of Health, Office of Dietary Supplements. (2021). Thiamin. Retrieved from ods.od.nih.gov

Food Sources High in Thiamine:

Harvard T.H. Chan School of Public Health. The Nutrition Source - Pork. Retrieved from hsph.harvard.edu
U.S. Department of Agriculture, FoodData Central. Sunflower seeds, dried. Retrieved from fdc.nal.usda.gov
U.S. Department of Agriculture, FoodData Central. Cereal grains and pasta. Retrieved from fdc.nal.usda.gov
U.S. Department of Agriculture, FoodData Central. Spinach, raw. Retrieved from fdc.nal.usda.gov
U.S. Department of Agriculture, FoodData Central. Broccoli, raw. Retrieved from fdc.nal.usda.gov

Deficiency and Daily Requirements:

Mayo Clinic. (n.d.). Thiamine (vitamin B1). Retrieved from mayoclinic.org
MedlinePlus. (2021). Thiamine. Retrieved from medlineplus.gov

THE KREBS CYCLE

The information provided about the Krebs cycle is based on foundational knowledge in biochemistry and cellular metabolism. While there are no specific external references for this simplified explanation, the content draws upon widely accepted principles in biochemistry and cellular biology taught in academic institutions and documented in textbooks.

Textbooks:
Berg, J. M., Tymoczko, J. L., & Stryer, L. (2019). Biochemistry (9th ed.). W. H. Freeman.
Voet, D., Voet, J. G., & Pratt, C. W. (2016). Fundamentals of Biochemistry: Life at the Molecular Level (5th ed.). Wiley.
Lehninger, A. L., Nelson, D. L., & Cox, M. M. (2017). Lehninger Principles of Biochemistry (7th ed.). W. H. Freeman.
Scientific Articles:
Krebs, H. A. (1940). "The citric acid cycle." Nobel Lecture, December 11, 1953. Retrieved from nobelprize.org
Srere, P. A. (1987). "The Metabolon: A Model for the Structure of Mitochondrial Citrate Synthase." European Journal of Biochemistry, 166(1), 79–86. DOI: 10.1111/j.1432-1033.1987.tb13568.x
Stryer, L. (1995). "The Citric Acid Cycle." In Biochemistry (4th ed., pp. 471–502). W. H. Freeman. ISBN: 978-0716720096

Online Resources:
Khan Academy. Cellular Respiration Introduction. Retrieved from khanacademy.org
Scitable by Nature Education. The Citric Acid Cycle: The Central Pathway of Carbohydrate, Lipid, and Amino Acid Metabolism. Retrieved from nature.com

Lonsdale, D. (2006). "A Review of the Biochemistry, Metabolism and Clinical Benefits of Thiamin(e) and Its Derivatives." Evidence-Based Complementary and Alternative Medicine, 3(1), 49–59. DOI: 10.1093/ecam/nek009
Manzetti, S., Zhang, J., van der Spoel, D. (2014). "Thiamin Function, Metabolism, Uptake, and Transport." Biochemistry, 53(5), 821–835. DOI: 10.1021/bi401618y
National Institutes of Health, Office of Dietary Supplements. (2021). Thiamin. Retrieved from ods.od.nih.gov

DISCLAIMER

The contents presented here are solely for neutral information and general education. The texts make no claim to completeness, nor can the timeliness, accuracy, and balance of the information provided be guaranteed. The texts in no way replace professional advice from a doctor or pharmacist, and they may not be used as a basis for independent diagnosis or initiation, modification, or termination of treatment for diseases. Always consult your trusted physician for health-related questions or complaints! I assume no liability for inconveniences or damages arising from the application of the information presented here.

VITAMIN B 1/ THIAMINE IN DETAIL

Did you know?!

VITAMIN B 1 THIAMINE

THE KREBS CYCLE

REFERENCES

DISCLAIMER

Subscribe

This website uses cookies.