BIOL 2360 – Biochemistry II
Extra Credit Assignment: Supplements
NAME OF SUPPLEMENT: L-CARNITIINE (Levocarnitine)
ALLMAX Nutrition is a company that produces the L-carnitine capsules. This manufacturer is claiming that this supplement L-Carnitine is essential for transporting long-chain fats into the mitochondria of the cell. It is capable of producing energy through the metabolism of fats in the body. The manufacturer claims that without L-Carnitine, these fats cannot be burned for energy and are instead stored as body fat. The manufacturer states that L-Carnitine enhances performance by increasing the body’s reliance on fat for energy thereby reducing the depletion of glycogen stores in the muscle. It is evident that by reducing lactic acid build up in the muscle can improve the performance of athletes using L-Carnitine since the duration of activity increases before the muscle is fatigued.
The active ingredient in this supplement is L-carnitine. It is an essential, non-toxic, natural dipeptide made from the essential amino acids lysine and methionine that is involved in the Carnitine Shuttle System in the body. L-carnitine is made in the liver and kidneys and is stored in the skeletal muscles, heart, brain and sperm. It is found in almost all the cells in the body. It plays an important role in transporting long chain fatty acids from the cytosol of cells into the inner membrane of the mitochondria.
In the cytosol long chain fatty acids (eg. 16 C palmitoyl) is converted to Fatty acyl CoA via the enzyme thiokinase. This fatty acyl CoA is taken up by carnitine which replaces the CoA with carnitine forming fatty acyl carnitine. This reaction is catalyzed by the enzyme carnitine acyltransferase 1 or CPT-1. This is the rate limiting step in beta oxidation since this enzyme of the Carnitine Shuttle system is inhibited by Malonyl CoA. An increase in carnitine in cells will increase the uptake of long chain fatty acids thus increasing the amount that is taken to the mitochondrial matrix where beta oxidation occurs to produce acetyl CoA, NADH and FADH2. The acetyl CoA enters the TCA cycle where 3 NADH, 1 FADH2 and 1 ATP is produced for every one acetyl CoA. The NADH and FADH2 can enter the electron transport chain where additional ATP is generated to sustain the energy needs of the body. Here every NADH produces 3 ATP and every FADH2 produces 2 ATP.
THE CARNITINE SHUTTLE SYSTEM:
This photo demonstrates the conversion of fatty acyl CoA to fatty acyl carnitine by the enzyme CAT-1 so that it can be transported across the inner mitochondrial membrane in to mitochondrial matrix.
REACTIONS IN BETA OXIDATION:
This picture demonstrates the four reactions in beta oxidation: oxidation, hydration, oxidation and thiolytic cleavage to produce acetyl CoA, NADH and FADH2.
Therefore, the manufacturer claim that the L-carnitine supplement will transport long-chain fatty acids into the mitochondria matrix is correct. The resultant energy produced from the formation of ATP is evident that it will increase the performance of individuals.
Studies have shown that L-carnitine supplements help the body to produce energy needed for the heart, brain and muscle movement. The supplement can be used to increase L-carnitine levels in people whose natural level of L-carnitine is too low because they have a genetic disorder. It is also used as a replacement supplement in strict vegetarians, dieters and in underweight or premature infants. L-carnitine can be used for conditions relating to heart such as chest pain, congestive heart failure (CHF), heart complications of a disease called diphtheria, heart attack, leg pain caused by circulation problems and high cholesterol. It is also seen associated in decreasing the infertility of males, improving brain development, aiding in controlling diabetes in patients and improving the overall performance and endurance of individuals.
National Institute of Health. “Carnitine: Facts Sheet for Health Professionals.” Accessed November 01, 2014. http://ods.od.nih.gov/factsheets/Carnitine-HealthProfessional/
Juvel-5. “Carnitine.” Accessed November 01, 2014. http://www.aminoacid-studies.com/amino-acids/carnitine.html
Volek, Jeff. “L-Carnitine burns body fat, boosts recovery, reduces muscle soreness and protects the heart.” Accessed November 01, 2014. http://www.nutritionexpress.com/ showarticle.aspx?id=1487
Allmax Nutrition. “L-Carnitine.” Accessed November 01, 2014. http://www.allmaxnutrition.com/ products-type/l_carnitine/
Allmax Nutrition. “L-Carnitine – Fat Loss Support Capsule.” Accessed November 01, 2014. http://tt.bodybuilding.com/store/allmax-nutrition/l-carnitine.html?&_requestid=772932
University of Maryland medical Centre. “Carnitine (L-carnitine).” Accessed November 01, 2014. http://umm.edu/health/medical/altmed/supplement/carnitine-lcarnitine