ATP: ESSENTIALITY OF GLUCOSE

Disaccharide: Glucose + Fructose

I sat down with Sarah from Sarah Kennard Health (also the host of the soon to be returning podcast) to answer a few questions about energy and metabolism.

Sarah: Hi Billy, firstly could you explain how we acquire energy?

Billy: Cellular respiration is the process by which living cells convert glucose and oxygen into energy in the form of ATP (adenosine triphosphate). This energy is used by cells to carry out their various functions, including growth, movement, and reproduction.

The process of cellular respiration can be broken down into three main stages: glycolysis, the Krebs cycle, and oxidative phosphorylation.

1. Glycolysis: This is the first stage of cellular respiration, and it takes place in the cytoplasm of the cell. During glycolysis, glucose is broken down into two molecules of pyruvate. This process also generates a small amount of ATP and NADH (nicotinamide adenine dinucleotide), which is a molecule that carries high-energy electrons.

2. Krebs cycle: This stage takes place in the mitochondria of the cell. During the Krebs cycle, pyruvate is further broken down into carbon dioxide and water. This process also generates more ATP and NADH.

3. Oxidative phosphorylation: This is the final stage of cellular respiration, and it takes place in the inner membrane of the mitochondria. During oxidative phosphorylation, the NADH and other electron carriers generated in the previous stages are used to create a proton gradient across the inner membrane of the mitochondria. This gradient is then used to produce a large amount of ATP.

Overall, cellular respiration is a crucial process for all living cells, as it allows them to generate the energy they need to carry out their various functions.

Sarah: How much ATP do we produce in each stage of cellular respiration?

Billy: The amount of ATP produced in each stage of cellular respiration varies, but in total, it results in the production of up to 36-38 ATP molecules per glucose molecule.

Here is a breakdown of the ATP produced in each stage of cellular respiration:

1. Glycolysis: During glycolysis, 2 ATP molecules are produced per glucose molecule, but it requires the input of 2 ATP molecules to start the process. Therefore, the net yield of ATP from glycolysis is 2 ATP molecules per glucose molecule.

2. Krebs cycle: The Krebs cycle generates 2 ATP molecules per glucose molecule, along with several other high-energy molecules such as NADH and FADH2, which are used in the next stage of respiration.

3. Oxidative phosphorylation: This stage produces the most ATP molecules, with up to 34 ATP molecules produced per glucose molecule. This process involves the electron transport chain, which uses the high-energy molecules generated in the previous stages to create a proton gradient across the inner membrane of the mitochondria. This gradient is then used to generate ATP through a process called chemiosmosis.

Overall, the total yield of ATP from cellular respiration can range from 36-38 ATP molecules per glucose molecule, depending on the efficiency of the process and the cell type. Also this factors in that we complete all stages.

Sarah: How much do humans produce per day?

Billy: It is difficult to estimate the exact amount of ATP produced by a human body per day since the amount of ATP required by an individual depends on various factors such as age, sex, body size, physical activity level, and health status. However, a rough estimate of ATP production in humans can be made based on the average daily calorie intake.

The average daily calorie intake for an adult is suggested to be around 2000-2500 calories. If we use this amount and assume that all these calories were derived from glucose, and the entire glucose undergoes all stages of cellular respiration, then we can calculate the total amount of ATP produced.

Each glucose molecule produces a net yield of 2 ATP molecules from glycolysis, 2 ATP molecules from the Krebs cycle, and up to 34 ATP molecules from oxidative phosphorylation. Therefore, a single glucose molecule can produce up to 38 ATP molecules.

Assuming that the average daily calorie intake produces 200 grams of glucose, then the total amount of ATP produced in a day would be approximately 760-950 ATP molecules per second or around 65 billion ATP molecules per day.

It is important to note that this is a rough estimate, and the actual amount of ATP produced by the body may vary depending on various factors such as diet, exercise, and overall health.

Sarah: How much ATP would be produced if a human ate a low carbohydrate diet?

Billy: If a human eats a low-carbohydrate diet, the amount of ATP produced by the body will be lower compared to a high-carbohydrate diet because glucose is the primary source of energy for cellular respiration.

When carbohydrates are restricted, the body will switch to alternative fuel sources such as fats and proteins, which can also undergo cellular respiration to produce ATP. However, the process of breaking down fats and proteins into usable energy requires more steps and is less efficient than breaking down glucose.

In a low-carbohydrate diet, the body will break down stored glycogen in the liver and muscles to produce glucose. Once the glycogen stores are depleted, the body will start breaking down fats and proteins to produce ATP. However, the energy yield from fats and proteins is lower than glucose, so the overall ATP production will be reduced.

It is difficult to estimate the exact amount of ATP produced by a low-carbohydrate diet since it depends on various factors such as the type of diet, the individual's metabolism, and physical activity level. However, research suggests that a low-carbohydrate diet can result in a reduction in ATP production compared to a high-carbohydrate diet. One would presume that in a prolonged state of glucose restriction, physiological responses to the stress would fight to ensure survival by sacrificing tissues to maintain more critical functions as noted in my book. We might expect to see higher stress hormones etc as markers.

Sarah: Does ATP availability differ between young children and aged subjects?

Billy: ATP availability can differ between young children and aged subjects due to several factors related to age-related changes in metabolism and physical activity levels.

In general, younger individuals tend to have higher ATP availability as evidenced by their faster metabolism and higher physical activity levels (unforced). Children have high metabolic rates that fuel their rapid growth and development, as a result, they have high energy demands and produce ATP at a faster rate than aged individuals.

On the other hand, aged subjects tend to have lower ATP availability due to age-related changes in metabolism and physical activity levels. As individuals age, their metabolism slows down, and they tend to lose muscle mass and physical function. This can result in lower physical activity levels, which can lead to or be the result of reduced ATP production.

Furthermore, age-related changes in the mitochondria, which are the organelles responsible for ATP production, can lead to decreased ATP availability. Mitochondrial dysfunction can result in decreased ATP production, which can lead to reduced energy levels and fatigue. We know from clinical research that throughout lifespan dietary sources gradually shift from very high carbohydrate sources (The fetus has been described as a ‘glucose-dependent parasite.’ Carbohydrate is the primary fuel for the fetus, accounting for about 80% of fetal energy consumption. The remaining 20% of fetal energy needs is provided by lactate, amino acids, and others. Fetal glucose utilization rates (5-7 mg/kg/min) are higher than in adults (2-3 mg/kg/min). The placenta maintains a continuous uninterrupted supply in utero—the hallmark of fetal life—by the process of facilitated diffusion.) See: Craig, B (2018). Consistent Eating for more details.

Overall, the difference in ATP availability between young children and aged subjects can be significant, with younger individuals having higher ATP availability due to their faster metabolism and higher physical activity levels.

Sarah: Does ATP power all cells in the body?

Billy: ATP is the primary source of energy for most cells in the body. It powers a wide range of cellular processes, including muscle contraction, nerve impulse transmission, and metabolic reactions.

However, not all cells in the body rely on ATP as their primary energy source. For example, red blood cells do not have mitochondria, which are the organelles responsible for ATP production through cellular respiration. Instead, they rely on glycolysis, which produces ATP without the use of oxygen.

Similarly, some cells, such as cancer cells, can use alternative energy sources such as glutamine to fuel their growth and proliferation.

Overall, while ATP is the primary energy source for most cells in the body, some cells can use alternative energy sources or pathways to generate energy.

Sarah: Do muscles and organs require more ATP to enter a relaxed state when compared to a contracted state?

Billy: Yes, muscles and organs require more ATP to enter a relaxed state compared to a contracted state. When muscles or organs are in a contracted state, they are actively using energy to maintain that state, which requires the continuous production of ATP. However, when they enter a relaxed state, they still require energy to maintain their structure and function, which also requires the production of ATP.

The process of muscle contraction requires energy from ATP hydrolysis, which powers the movement of myosin filaments over actin filaments. Once the contraction is complete, the muscle must use energy to pump calcium ions back into the sarcoplasmic reticulum, which requires the use of increased amounts of ATP. Additionally, the muscle must also maintain its structural integrity and repair any damage that may have occurred during the contraction, which also requires the use of ATP.

Sarah: So a tight muscle, or cramp could be due to lack of ATP availability

Billy: Yes, a tight muscle or cramp can be due to a lack of ATP availability. When a muscle is contracting, it requires a continuous supply of ATP to fuel the process of muscle contraction. If there is a lack of ATP availability, the muscle may not be able to relax properly, which can result in a tight muscle or cramp.

Several factors can contribute to a lack of ATP availability, including:

1. Low energy stores: If the body's energy stores, such as glycogen, are depleted, there may not be enough ATP available to support muscle contraction.

2. Poor blood flow: If there is poor blood flow to the muscle, it may not receive enough oxygen and nutrients to support ATP production.

3. Mitochondrial dysfunction: If there is dysfunction in the mitochondria, the organelles responsible for ATP production, the muscle may not be able to produce enough ATP to support muscle contraction.

4. Electrolyte imbalances: Electrolytes such as potassium, calcium, and magnesium are essential for muscle contraction. If there is an imbalance in these electrolytes, it can affect the muscle's ability to contract and relax properly.

Overall, a lack of ATP availability can contribute to muscle tightness and cramps, and it is important to address the underlying cause of ATP deficiency to prevent and treat these issues.

Sarah: Massage has been shown to have various beneficial effects on the body, including stimulating ATP production in the muscles.

Billy: Massage therapy can increase blood flow to the muscles, which can provide more oxygen and nutrients to the muscle cells, including the mitochondria. This can help support ATP production and energy metabolism in the muscle cells.

Additionally, massage therapy can help relieve muscle tension and reduce muscle damage, which can also contribute to improved ATP production. When the muscles are tense or damaged, they require more energy to maintain their structure and function, which can reduce the amount of ATP available for other cellular processes.

Massage therapy can also stimulate the release of endorphins, which are natural painkillers that can help reduce muscle pain and discomfort. This can help improve muscle function and reduce the need for energy to cope with pain, allowing more ATP to be available for other cellular processes.

Overall, massage therapy can be an effective way to stimulate ATP production and improve energy metabolism in the muscles, which can have a range of beneficial effects on the body. As a longterm plan alongside massage for therapeutic effect, one should aim to restore good ATP generation through good diet etc.

Sarah: As people age they tend to eat a higher fat diet, does this reduce ATP availability?

Billy: As people age, their dietary patterns may change, and some individuals may consume a higher fat diet. While a high-fat diet can provide the body with a significant amount of energy, it may also reduce ATP availability in some cases.

One reason for this is that the body requires oxygen to metabolise fats and produce ATP. When fat is metabolised in the absence of oxygen (anaerobic metabolism), it produces less ATP compared to when it is metabolised in the presence of oxygen (aerobic metabolism).

Overall, while a high-fat diet can provide the body with energy, it may also reduce ATP availability in some cases, particularly if the diet is high in saturated and trans fats and contributes to insulin resistance. A balanced diet that includes moderate amounts of "healthy" fats, alongside sufficient carbohydrates, and protein is essential for optimal ATP production and energy metabolism.

Sarah: Has ATP availability been measured in diabetic patients?

Billy: Yes, ATP availability has been measured in diabetic patients. In diabetes, the body's ability to utilise blood glucose levels is impaired, which can lead to a reduction in ATP availability in some cases.

One study published in the Journal of Clinical Endocrinology and Metabolism measured ATP availability in skeletal muscle biopsies taken from diabetic and non-diabetic individuals. The researchers found that diabetic patients had a lower ATP content and a decreased rate of ATP production in their skeletal muscle cells compared to non-diabetic individuals.

Another study published in Diabetes Care measured ATP levels in the hearts of diabetic and non-diabetic patients using magnetic resonance spectroscopy. The researchers found that diabetic patients had a reduced rate of ATP synthesis in their hearts compared to non-diabetic individuals.

These studies suggest that diabetes can have a negative impact on ATP availability in various tissues, including skeletal muscle and the heart. This can lead to reduced energy production and contribute to the development of complications associated with diabetes, such as cardiovascular disease and neuropathy.

Sarah: When people eat lower carbohydrates and engage in breathless exercise, it can lead to a reduction in ATP availability in some cases.

Billy: Carbohydrates are the primary source of energy for the body, and they are converted into glucose, which is then used to produce ATP through the process of cellular respiration. When carbohydrate intake is low, the body may shift towards using other sources of energy, such as fats, to produce ATP. However, the production of ATP from fats is less efficient compared to the production of ATP from carbohydrates, which can lead to a reduction in ATP availability.

Breathless exercise, such as high-intensity interval training or sprinting, can also lead to a reduction in ATP availability. During high-intensity exercise, the body relies on anaerobic metabolism to produce ATP, which produces ATP at a faster rate compared to aerobic metabolism. However, anaerobic metabolism produces less ATP overall and can lead to the accumulation of metabolic byproducts, such as lactic acid, which can impair ATP production and reduce ATP availability.

Overall, low carbohydrate intake and breathless exercise can lead to a reduction in ATP availability in some cases. However, the extent of this reduction will depend on various factors, such as the individual's overall metabolic health, exercise intensity and duration, and nutritional status.

Sarah: Does mouth breathing decrease ATP levels?

Billy: Mouth breathing may not directly decrease ATP levels, but it can affect the body's oxygenation status and therefore, indirectly impact ATP production.

During mouth breathing, air is often taken in through the mouth rather than the nose. This can lead to a decrease in the amount of air that is filtered, humidified, and warmed before it reaches the lungs, which can affect the body's ability to absorb oxygen.

Oxygen is essential for ATP production through the process of cellular respiration, as it serves as the final electron acceptor in the electron transport chain. If there is a decrease in the amount of oxygen available, ATP production can be reduced.

Additionally, mouth breathing can lead to an increase in respiratory rate, which can cause a decrease in carbon dioxide levels in the blood. Carbon dioxide plays a critical role in regulating oxygenation and ATP production, as it helps to dilate blood vessels and improve blood flow to tissues. A decrease in carbon dioxide levels can therefore reduce oxygen delivery to cells and impair ATP production.

Overall, while mouth breathing may not directly decrease ATP levels, it can affect oxygen delivery to cells and impair ATP production through the process of cellular respiration. It is important to breathe through the nose whenever possible to optimize oxygenation and energy metabolism.

Nasal breathing has several advantages over mouth breathing.

First, the nose is designed to filter, warm, and humidify the air we breathe, which helps protect our lungs and airways from irritants and infections. When we breathe through our nose, the hairs and mucus lining in our nostrils trap particles and pathogens that could cause harm if they enter our lungs.

Second, nasal breathing also helps regulate the amount of air we take in, which can prevent over-breathing and hyperventilation. The nasal passages are narrow, which naturally limits the amount of air we can inhale at once, and the resistance of the nasal airway can help regulate our breathing rate and depth.

Third, nasal breathing helps stimulate the production of nitric oxide, a gas that has several health benefits, including relaxing blood vessels, increasing oxygen uptake, and boosting immune function. Nitric oxide is produced in the sinuses and released into the nasal cavity during breathing.

Mouth breathing, on the other hand, bypasses the natural filtration, warming, and humidifying functions of the nose, and can lead to dry mouth, throat irritation, and an increased risk of respiratory infections. Mouth breathing can also cause snoring, sleep apnea, and other sleep-related problems, as well as dental and orthodontic issues.

In summary, nasal breathing is the natural and preferred way to breathe, as it offers several health benefits and helps protect our lungs and airways from harm. Mouth breathing should be avoided whenever possible, particularly during sleep or physical activity, when the demand for oxygen is higher.

Sarah: Exhaling through the mouth causes a loss of excessive amounts of co2 relative to o2 intake

Billy: Exhaling through the mouth does not necessarily cause a loss of excessive amounts of carbon dioxide (CO2) relative to oxygen (O2) intake, but it can be a problem if it becomes chronic. When we inhale air through our mouth, we take in oxygen-rich air that is then transported to the lungs, where it diffuses into the bloodstream and is carried to the body's cells. During this process, some of the oxygen is used by the cells in metabolic processes, and CO2 is produced as a waste product.

When we exhale, we release CO2 back into the air, and the air we exhale has less oxygen and more CO2 than the air we inhaled. The amount of CO2 that we exhale depends on several factors, including our metabolic rate, the amount of physical activity we engage in, and the composition of the air we inhale.

Mouth breathing can contribute to fatigue because it affects the efficiency of breathing and can lead to hyperventilation, which can result in a loss of CO2 and changes in blood pH levels. When we breathe through our mouth, we bypass the natural filtration, warming, and humidifying functions of the nose, which can result in dry mouth, throat irritation, and an increased risk of respiratory infections.

Mouth breathing can also result in shallow breathing or over-breathing, which can cause an imbalance in the oxygen and carbon dioxide levels in the blood. This imbalance can lead to symptoms such as lightheadedness, shortness of breath, and fatigue.

Additionally, mouth breathing can be associated with sleep disorders, such as sleep apnea, which can cause daytime fatigue due to disrupted sleep patterns. When a person has sleep apnea, their breathing may stop for short periods of time during sleep, causing them to wake up briefly and interrupting the natural sleep cycle.

Overall, breathing through the nose is the preferred method of breathing as it helps to filter, warm, and humidify the air we breathe, and also helps regulate the amount of air we take in. If you experience symptoms of fatigue, it is recommended to speak with a healthcare professional to determine the underlying cause and appropriate treatment.

Buteyko is a breathing technique that was developed by Russian physician Konstantin Buteyko in the 1950s. The Buteyko Method is designed to help people with various breathing problems, such as asthma, chronic obstructive pulmonary disease (COPD), and sleep apnea, to improve their breathing patterns and reduce symptoms.

The Buteyko Method focuses on reducing breathing volume and slowing down the breathing rate, which can help improve oxygen and carbon dioxide balance in the body. The technique involves a series of exercises, including breathing exercises, relaxation techniques, and lifestyle changes, that aim to help individuals develop a more efficient and healthy breathing pattern.

The Buteyko Method is based on the principle that over-breathing, or hyperventilation, can lead to an imbalance in oxygen and carbon dioxide levels in the body, which can cause a range of symptoms such as fatigue, anxiety, and shortness of breath. The method teaches individuals to breathe through the nose, rather than the mouth, and to focus on breathing using the diaphragm, rather than the chest.

Proponents of the Buteyko Method claim that it can help improve lung function, reduce symptoms of asthma and other respiratory conditions, and improve overall health and well-being. However, more research is needed to fully understand the benefits of this technique and its effectiveness for different conditions.

It is important to note that the Buteyko Method should not be used as a replacement for medical treatment, and individuals with breathing problems should always consult with their healthcare provider before starting any new breathing technique or exercise program.

The Bohr effect is a physiological phenomenon that describes the relationship between carbon dioxide (CO2) and oxygen (O2) in the blood.

In the presence of CO2, the pH of the blood decreases, making it more acidic. This increase in acidity causes a shift in the oxygen-hemoglobin dissociation curve, which means that hemoglobin (the protein that carries oxygen in the blood) releases more oxygen into the tissues that need it.

In other words, when CO2 levels increase in the blood, the affinity of hemoglobin for oxygen decreases, making it easier for oxygen to be released to the tissues that need it. This is particularly important during exercise, when the muscles require more oxygen to generate energy and produce CO2 as a waste product.

The Bohr effect is important for the regulation of breathing rate and depth, as it helps to ensure that the body receives enough oxygen and removes enough CO2 to maintain proper pH balance in the blood. If CO2 levels increase too much, the body will respond by increasing breathing rate and depth to remove the excess CO2 and restore the balance.

The Bohr effect is named after the Danish physiologist Christian Bohr, who first described the phenomenon in 1904. The effect is a fundamental concept in respiratory physiology and plays an important role in understanding how the body regulates gas exchange and pH balance in the blood.

Hyperventilation and mouth breathing can lead to a decrease in carbon dioxide levels in the body and an increase in oxygen levels. While this may seem like a good thing, it can actually impact metabolism in several ways.

Firstly, when carbon dioxide levels decrease, it can cause blood vessels to constrict, reducing blood flow and oxygen delivery to tissues. This can actually result in a decrease in ATP production since oxygen is required for the electron transport chain, which generates ATP in the mitochondria.

Additionally, hyperventilation and mouth breathing can lead to respiratory alkalosis, a condition in which the blood becomes too alkaline due to excessive loss of carbon dioxide. This can lead to a shift in the balance of electrolytes in the body, which can impact muscle and nerve function, and potentially reduce ATP production.

Overall, while hyperventilation and mouth breathing may temporarily increase oxygen intake, they can also disrupt the delicate balance of gases and electrolytes in the body, which can ultimately impact metabolism and ATP production. It is important to maintain normal breathing patterns for optimal metabolic function.

Sarah: Does a lower carbohydrate diet reduced CO2 in the body? Is CO2 produced better when carbohydrates are metabolised at a higher level than fats and proteins?

Billy: A lower carbohydrate diet does not necessarily reduce carbon dioxide (CO2) in the body. While carbohydrates are metabolised to produce CO2, the overall amount of CO2 produced depends on various factors, including the type of carbohydrate, the rate of metabolism, and the individual's metabolic rate and activity level.

It is true that the metabolism of carbohydrates produces more CO2 per unit of oxygen consumed than the metabolism of fats or proteins. This is because carbohydrates have a higher ratio of oxygen atoms to carbon atoms compared to fats or proteins, and the process of metabolising carbohydrates requires more oxygen to be consumed per unit of CO2 produced.

However, it is important to note that the overall amount of CO2 produced during metabolism depends on many factors, including the ratio and amounts of carbohydrates, fats, and proteins consumed, as well as the individual's metabolic rate and level of physical activity.

A lower carbohydrate diet may not necessarily lead to a reduction in CO2 production if it is replaced with higher intakes of protein or fat. In fact, high protein diets can result in increased CO2 production due to the higher metabolic rate required for protein digestion and metabolism, but the impact due to restricted carbohydrate tends to be negative over time..

In summary, while the metabolism of carbohydrates does produce more CO2 per unit of oxygen consumed than the metabolism of fats or proteins, the overall amount of CO2 produced during metabolism depends on many factors and cannot be determined solely based on the macronutrient composition of the diet.

Sarah: Thanks for your time Billy, I think this will be useful for many that wish to understand the value of energy in a world that seems to perpetuate energy avoidance.