Fitness of the body & mind - Part III (Aerobic Glycolysis)

We saw in the previous article that the first step,glycolysis in both aerobic as well as anaerobic, takes place in the cytoplasm of the cell. In this article, we will see how aerobic glycolysis is carried out.

Aerobic glycolysis, also known as Cellular respiration, requires oxygen for harvesting energy. There are 3 steps in this process: (1) glycolysis (2) Krebs cycle or citric acid cycle (3) electron transport chain. Although the glycolysis takes place in the cytoplasm of the cell, the Krebs cycle and electron transport chain occur within the mitochondria for cellular respiration. In aerobic glycolysis, mitochondria are the engines of our cells where sugar is burned for fuel and the exhaust is CO₂ and H₂O.

Irrespective of the metabolic pathways(aerobic or anaerobic), the first step glycolysis produces a total of 4 ATP molecules but 2 are used up in the process. In aerobic metabolism, additional ATPs are produced during Krebs cycle and electron transport chain resulting in a grand total of 40 ATP molecules from the breakdown of one glucose molecule. 2 ATPs are already lost in glycolysis(breakdown of glucose to pyruvic acid). To move the pyruvic acid into mitochondria, the process uses one ATP. Thus for each glucose molecule which produces 2 pyruvic acids(2 ATPs are lost here),a net total of 36 ATPs are produced as 2 more ATPs are lost to push the 2 pyruvic acids into the mitochondria.

Each pyruvic acid molecule needs to react with 3 oxygen molecules to form 3 carbon dioxide molecules and 3 water molecules.

C₆H₁₂O₆ + 6O₂ =3CO₂ + 3H₂O + (energy for the cell, ie ATP)

Or, you can write it in an alternate way(we are just re-grouping the terms),

(C₃H₆O₃ + 3O₂)+ (C₃H₆O₃ + 3O₂) = 3CO₂ + 3H₂O + (energy for the cell, ie ATP)

Remember, glucose is broken down to 2 pyruvic acid molecules as

C₆H₁₂O₆ = 2(C₃H₆O₃)

You don't need to know the details of the Krebs cycle and electron chain transport to lose/gain weight and to do exercises as it involves some technical terms! If you have to take an exam or are further interested in knowing, you can refer to any "good" text book on General Chemistry or Physiology/Anatomy.Or, you can buzz me for details through email!

Things to keep in mind:

Glucose(also known as Dextrose),Fructose(found in fruits and honey) and Galactose are simple sugars called monosaccharides. All the living cells use glucose as a source of energy and metabolic intermediate.

Sucrose(Table sugar) = glucose(50%) + fructose(50%)

Lactose(found in milk and it makes to 2-8% of milk)= glucose + galactose

Maltose(used in brewing beer) = glucose + glucose

Sucrose, Lactose, Maltose are disaccharides. Starch, a polysaccharide(complex carbohydrate) is a chain of many glucose units/molecules.

People who are lactose intolerant, basically lack the enzyme "lactase" in their body which is essential to digest the milk. This enzyme is secreted by the small intestinal villi and without this enzyme, the lactose will not be broken down into its sub units glucose and galactose. Then the unbroken lactose provide food for gut flora that produces gas. People with lactose intolerant will develop bloating and constipation. Some enzymes are available in the market.

Next time when you visit any grocery store, don't go with anybody(its not a picnic spot!)go alone and go through all the aisles reading the food labels patiently. If some names sound strange, note it down and find out. You will uncover yourself mentally. Many people gain weight for a simple reason that they don't pay much attention to the food/body and talk too much while eating. So they don't keep track of the quantity that's going into the body!!!

We will see in the next article how we can burn calories by losing bad fat and gaining muscle weight through certain exercises that keep our energy levels high. Isn't that cool?

Fitness of the body & mind - Part II(Anaerobic Glycolysis)

Note: In the previous article, I mentioned that a Physician purposely let B Lymphocytes circulate in the bloodstream in some cases of Bone Marrow Transplantation. Let me correct myself by writing precisely it is the "Hematologist"(as Physician is a general word), who deals with the disorders/diseases of the blood.

Energy production of ATP synthesis can occur through either anaerobic or aerobic glycolysis. We will see in this article how anaerobic metabolism is carried out in our body. Our body depends on oxygen to carry out many chemical reactions inside our body. Aerobic means "dependent" on oxygen. Instead of using "presence" and "absence" of oxygen, which can convey a wrong message, I like to use "dependent" and "independent" of oxygen. So, anaerobic means, the body doesn't depend on oxygen to carry out the chemical reactions.

Carbohydrate metabolism(anaerobic/glycogen) is much more efficient & faster than the fat metabolism. You will understand this better when you see the details of the pathways in aerobic as well as anaerobic metabolism and the relative performance of these two reactions in sprinters and marathoners. To put it in a different way, anaerobic metabolism(sprinters,high jumpers,weight lifters)means "short intervals, high speed" and aerobic metabolism(marathoners) means "longer intervals, low/reduced speed". Any exercise that persists for more than roughly 3 minutes must be powered by aerobic metabolism.

There are two ways in which a cell can harvest energy from food:(1)Fermentation and (2) Cellular respiration. The first process/step, irrespective of aerobic or anaerobic metabolism is "glycolysis". Glycolysis is the breakdown of glucose(C₆H₁₂O₆) into two pyruvates(C₃H₆O₃). That means, the 6-carbon glucose splits into 2 3-carbon pyruvic acid. Glycolysis takes place in the cytoplasm of the cells. This pyruvate is broken down differently in aerobic and anaerobic reactions.

Anaerobic metabolism/Fermentation: These pyruvic acid molecules are turned into some waste products and very little energy(ATP). Actually 4 ATP molecules are produced but 2 are used up in the process. It is similar to: our body needs calories/energy to even eat/consume calories. So, in this process only 2 ATPs are produced. There are 2 types of fermentation:

(i) Lactic acid fermentation: This is done by some fungi or some bacteria like lactobacillus acidophillus found in yogurt and sometimes by our muscles(in the case of sprinters). Normally our muscles, like any other body part, do cellular respiration/aerobic using oxygen supplied by the lungs and blood. However, under greater exertion(like sprint), when the oxygen supplied by the lungs and blood can't get there fast enough to keep up with the muscle's needs, our muscles can switch over to lactic acid fermentation. In lactic acid fermentation process,the 3-carbon pyruvic acid molecules are converted to lactic acid. It is the presence of lactic acid in the yogurt that gives it sour taste and its the same lactic acid in the muscles that makes them so sore and stiff the next day. Once our muscles form lactic acid, they can't do anything else with it, until it is washed away by the bloodstream and carried to the liver which is then able to get rid of the waste(Remember liver's duty is to remove toxins/wastes from our body?). To reduce the acidity(soreness/stiffness), drink plenty of water with a total of 1/4-1/2 teaspoon of sodium-bi-carbonate popularly known as Baking Soda, NaHCO₃. Baking soda is alkaline, so it will neutralize the acidity building up due to fermentation.

(ii) Alcohol fermentation:This is done by some yeast(used in bread, pizza dough, beer,wine!) and some bacteria. The waste products are ethanol and carbon-dioxide. In bread making, it is the CO₂ that forms and gets trapped between the gluten(long protein in wheat)molecules that causes the bread to rise and the ethanol evaporating gives it a wonderful smell! Many college students and regular boozers are very familiar and probably expert(!) with the effects of ethanol in beer and wine...

Fitness of the body and mind - Part I

Many people face challenge when it comes to doing exercise or losing weight. Gaining weight is not a problem! There are zillions of books each claiming its own technique/method as the best to losing weight. None addresses from layman standpoint. This article is an attempt to explain to a person who doesn't know anything about the physiology/anatomy(how our body is structured and functions internally) and how the right exercises, coupled with healthy and power foods play vital role in keeping oneself physically and mentally fit.

Keep in mind, both body(classified as gross matter) and mind(subtle matter) are matter only!

All the foods that we eat contain a combination of protein, carbohydrates and fat apart from vitamins and minerals. But protein, carbohydrates and fat are macromolecules and they can't directly nourish the 100 trillion(1 trillion is 1 followed by 12 zeros) cells in the human body out of which 100 billion cells are brain cells and 20-30 trillion cells are Erythrocytes(also known as red blood cells). All the macro molecules are broken down to a much smaller unit called ATP(Adenosine Tri Phosphate) which is the currency of energy at cellular level.

In Biology, people do research at molecular level, in Chemistry at atomic level and in Physics from particle to astronomical level. All the three subjects deal with matter only. Physics encompasses the other two as far matter is concerned!

The final end product of all the three macro nutrients are as follows:

1) Protein --> ATP, CO₂(carbon-di-oxide),H₂O(water), urea(a waste which should be excreted through liver and kidneys).

1 gram(gm) of protein equals 4 kcalories.

Excess protein puts stress on the organs liver and kidneys to overwork to get rid of the toxin that builds up in the bloodstream. Bodybuilders(who are on high protein diet) normally have, in their later years, kidney failure, urinary calcium loss. High protein intake is one of the main reasons for the high incidence of Osteoporosis in the United States despite the heavy consumption of milk which contains roughly 30% calcium! Blood maintains its alkalinity in a narrow range(pH - 7.35-7.45).

The pH stands for the potential of hydrogen ion, measures the acidity or alkalinity/base of a solution/substance. I will explain the alkalinity/base and acidity later in conjunction with foods. For the time being, take it for granted that pH ranges from 0 to 14. A pH less than 7 is acidic and more than 7 is alkaline. A pH of 7 is neutral and distilled water is neutral. Saliva and urine must be slightly acidic(around 6.7),stomach is acidic as it produces hydrochloric acid, whose pH is 0, acts as protection against microorganisms including HIV(Human Immunodeficiency Virus which disables the immune system(T white blood cells/Leukocytes) thereby exposing the person to all kinds of infections).

There are 5 types of white blood cells and one is a lymphocyte and other 4 are basophils, neutrophils, monocytes and esonophils. Lymphocytes are 2 types namely B lymphocytes & T lymphocytes. B stands for "Bone Marrow" and T stands for "Thymus". In the case of HIV, T cells are targeted by the virus. T cells circulate throughout our bloodstream and B cells normally don't come out of the Bone Marrow. In cases of "Bone Marrow Transplant", sometimes the Physician purposely let healthy B cells circulate in the bloodstream. If a person, who is HIV positive, drinks half glass of water and another person by mistake, without knowing, drinks the remaining water, the latter will not get the virus as the stomach acid will kill the virus(it can't thrive in such acidic atmosphere)unless the latter had some cuts in his mouth or had sex(in which case the virus has direct access to the bloodstream and thus slowly disable the white blood cells)! But the stomach itself is protected from the acid by the thick, protective mucus layer and by secretin buffering with sodium bi carbonate which is alkaline. Heartburn,peptic ulcers can develop when these mechanisms fail.

For optimal health our body should be slightly alkaline. Small intestine is alkaline. When blood pH goes slightly acidic, the consequences can be devastating. So our body will do anything to keep the blood alkaline. Calcium(its pH is 12) is an alkaline mineral which is abundant in the bones. When blood pH goes down, due to high intake of protein which builds up uric acid,the body will take calcium from the bones to maintain the blood pH. Protein is not the major source of energy for the body. It is mainly for the repair and maintenance of tissues and muscles. When a person goes on a carbohydrate deprived diet, and eats lot of protein and fat, then the body will break down fat first, then protein. The best example is prisoners who are not fed properly. So over time, the body will break down protein to sustain the energy body needs. The skin-bone structure of prisoners is clear evidence of the conversion of muscle protein to blood sugar to support their life.

2) Carbohydrates --> ATP,CO₂,H₂O. A healthy diet should consist of 50-65% carbohydrate to avoid weight gain/loss. When a person thinks that carbohydrate is junk and protein is good(I have lot of friends who think like this and they neither have energy nor lose weight because of their stupidity!) and go on carbohydrate deprivation, he/she is going against body's natural mechanism. After the digestion of carbohydrates, the end products are glucose, fructose and galactose. For active adults(who do exercise actively!), 60-65% should come from carbohydrates.

Glucose(C₆H₁₂O₆),followed by Fat for long term energy store, is the main source of energy for the body including brain cells,red blood cells,CNS(central nervous system),retina all of which require constant supply of glucose. Just 40 minute of resting activity consumes up the entire circulating blood sugar. 15 minutes of walking is taken up by the entire blood glucose. The normal blood glucose(assuming that an adult male has 5 litres of blood) is 3.3g to 7g. Brain alone consumes 6g of glucose an hour! The only organ, on a short term basis, that can produce glucose is liver which produces 200mg per hour. It is the duty of the liver to maintain stable blood sugar levels. Only during prolonged fasting, kidneys also produce glucose.

Liver is the one that metabolises the food and also the sole organ for removing toxins from our body. After small intestine, all the important nutrients now interact directly with the liver and bloodstream and the unwanted residue go to the large intestine and finally come out as fecal matter. When this organ is screwed up, death is assured. Let me give you an example of the power of this organ. When a person drinks alcohol, say whiskey which is normally 40% or 80 proof, the liver stops metabolising everything else and solely concentrates on alcohol and try to get it out of the bloodstream as fast as it can. Whenever you subject your body with toxicity, you put this miracle organ to work around the clock to keep the body in stable conditions. So, don't mess up with this organ. I have humble respects for this organ.

Only liver and kidneys are sugar producers. All other organs are sugar burners and they take up glucose from the blood and using it for energy production. Glucose can't enter the cell directly due to its molecular weight(180 g/mol) and it is further broken down through "aerobic" or "anaerobic" metabolism to a much smaller unit ATP that cells can use. The body first breaks down carbohydrates, then fat and then protein. Anything excess, more than what the body's energy needs, will go to storage as fat in adipose tissue, and carbohydrates as glycogen in liver and muscle. To put it bluntly, consider glucose as your checking account and fat as your savings account!!! You don't touch your savings until your checking account is completely emptied up.

One unit/gram of carbohydrate again equals 4 kcalories.

3) Fat --> ATP,CO₂,H₂O

Fat serves many purposes in our body. Without some percentage of fat, one can bruise oneself very easily. Fat acts as insulation(in the skin)regulating the temperature of the skin. It also acts as protection for our knees, kidneys(which move flexibly,when you walk,as they are nicely cushioned by the surrounding fat) and "heart" which is hidden behind the adipose tissue. There are good fats and bad fats. The degree of saturation of the fatty acids determine if the fatty acids are good or bad. If the fatty acids don't consist of any carbon double bond, then it is a saturated/bad/hydrogenated fat(vegetable, palm oil). If it contains at least one carbon double bond, then its called mono unsaturated/good fat(olive oil) and it is called polyunsaturated fat if it contains more than one double bond(Canola has many double bonds). You don't use these two oils at high temperatures as the double bonds break and become hydrogenated/saturated. So, for deep frying, use peanut, or vegetable oil. But try to avoid fried foods as much as you can for the sake of your heart:-) In case you eat fried stuff, make sure you get ample exercise that day!

We will see how different exercises utilise these three nutrients and how one can easily shed pounds of junk fat and gain muscle when one understands the basic metabolism of the three nutrients. Ideally, one should incorporate exercises that are 60% aerobic and 40% anaerobic...