Metabolism

Metabolism refers to the chemical processes that take place as your body converts foods and drinks into energy. It is a complex process that combines food and oxygen to create and release energy; the conversion of food to building blocks for proteins, lipids, nucleic acids, and carbohydrates with the elimination of metabolic wastes. Carbohydrates, lipids, and proteins all ultimately break down into glucose, which then serves as the primary metabolic fuel. Glucose then, is central to energy consumption.

Glucose "... serves as the major precursor for the synthesis of different carbohydrates like glycogen, ribose, and deoxyribose, galactose, glycolipids, glycoproteins, and proteoglycans." ¹

A healthy metabolism relies upon proteins to catalyze biochemical reactions. These reactions include breaking down nutrients, synthesizing molecules, and producing energy. Enzymes, which are specialized proteins, play a crucial role in these processes. For instance, enzymes like amylase break down carbohydrates, lipases metabolize fats, and proteases digest proteins. Additionally, proteins are essential for maintaining cell structure, transporting molecules, and supporting immune function. Overall, proteins are the workhorses of metabolism, ensuring that our bodies function optimally. As we age, our digestive system may become less efficient. This can impact the breakdown of proteins into amino acids during digestion.

A healthy metabolism also relies upon fats and lipids to provide energy, support cell structure, and facilitate essential biological processes. Let’s explore their roles:

1. Energy Source: Fats are a concentrated energy source, providing more than twice the calories per gram compared to carbohydrates or proteins. During periods of fasting or low glucose availability, our bodies break down stored fats (triglycerides) into fatty acids and glycerol. These fatty acids can then enter the citric acid cycle (Krebs cycle) to produce ATP (adenosine triphosphate), the primary energy currency of cells.
2. Cell Membranes: Lipids, including phospholipids and cholesterol, are crucial components of cell membranes. Phospholipids form the lipid bilayer, creating a semi-permeable barrier that encloses cells and organelles. Cholesterol helps maintain membrane fluidity and stability.
3. Hormone Production: Steroid hormones (such as cortisol, estrogen, and testosterone) are derived from cholesterol. These hormones regulate various physiological processes, including metabolism, immune response, and stress.
4. Insulation and Protection: Adipose tissue (composed of fat cells) acts as insulation, helping regulate body temperature. Fat also cushions and protects vital organs. Fat-Soluble Vitamins: Vitamins A, D, E, and K are fat-soluble, meaning they require dietary fats for absorption. For example, vitamin D is essential for calcium metabolism and bone health.
5. Long-Term Energy Storage: Excess dietary energy is stored as triglycerides in adipose tissue. When needed, these stored fats are broken down to release energy.

Fats and lipids play multifaceted roles in maintaining health, from energy provision to cellular function. Balancing the types of fats (saturated, unsaturated, and trans fats) and overall intake is essential for optimal well-being.

Metabolic Pathways

Metabolic pathways are intricate networks of chemical reactions that occur within living organisms. These pathways enable the conversion of molecules (substrates) into different forms, providing energy, building blocks, and maintaining cellular functions. Here are some key points:

1. Organization: Metabolic pathways are organized into chains or cycles of enzyme-catalysed reactions.

Chains: In a linear chain, substrates move step by step through a series of reactions. Each reaction is catalyzed by a specific enzyme. Cycles: Cyclic pathways involve a continuous loop of reactions. The end product of one cycle becomes the starting material for the next round.

2. Enzyme-Catalyzed Reactions:

Enzymes are proteins that accelerate chemical reactions without being consumed. Each step in a metabolic pathway is catalyzed by a specific enzyme. Enzymes lower the activation energy required for reactions, making them more efficient.

3. Anabolism and Catabolism:

Anabolic pathways build complex molecules from simpler ones. Examples include protein synthesis and DNA replication. Catabolic pathways break down complex molecules into simpler ones, releasing energy. Glycolysis and the citric acid cycle (Krebs cycle) are catabolic pathways.

4. Energy Currency: ATP:

Adenosine triphosphate (ATP) is the universal energy currency in cells. ATP is generated during catabolic reactions (e.g., oxidative phosphorylation) and used in anabolic processes (e.g., protein synthesis).

5. Examples of Metabolic Pathways:

Glycolysis: A catabolic pathway that breaks down glucose into pyruvate, producing ATP and NADH. Citric Acid Cycle (Krebs Cycle): A cyclic pathway that generates ATP and high-energy electron carriers (NADH and FADH₂).

6. Regulation:

Metabolic pathways are tightly regulated to maintain homeostasis. Feedback inhibition, allosteric regulation, and hormonal control modulate enzyme activity.

In summary, metabolic pathways are dynamic, interconnected systems that sustain life by orchestrating countless reactions. They adapt to energy demands, environmental cues, and cellular needs.

Mitochondria

Mitochondria are remarkable organelles found in most cells. Their primary function is to generate adenosine triphosphate (ATP), the energy currency of our bodies. Here’s how they do it:

1. ATP Production:

Mitochondria perform cellular respiration, a process that converts nutrients (such as glucose and fatty acids) into ATP. The citric acid cycle (Krebs cycle) and the electron transport chain take place within mitochondria. These processes extract energy from food molecules and use it to create ATP.

2. Energy Powerhouses:

ATP fuels essential cellular activities, including muscle contraction, nerve signaling, and maintaining body temperature. Without functional mitochondria, our cells wouldn’t have enough energy to survive.

3. Other Roles:

Mitochondria are involved in calcium regulation, apoptosis (programmed cell death), and metabolism of amino acids and lipids. They also play a role in reactive oxygen species (ROS) management. In summary, mitochondria are like tiny power plants, ensuring our cells have the energy needed for life.

Here is a Video about the ""Role of Nutritional Care in Mitochondrial Health"

If the body cannot breakdown food, absorb nutrients and eliminate toxins effectively, metabolism will suffer. Improving digestion is key to making improvement in body composition, energy and immune responsed.

Food and drink contain essential nutrients: a combination or selection of carbohydrates, fats, proteins, vitamins, or minerals. Fortified foods contain vitamins and minerals that are added after processing. Ingredients used widely in the production of processed foods such as saturated fats, added sugars, and sodium are markers of poor diet quality due to their effect on heart disease, obesity, and high blood pressure. "It is estimated that processed foods contribute about 90% of the total calories obtained from added sugars. Altered and processed food also alters the metabolist of those foods." ²

“The main message is that a diet of foods rich in particular nutrients is very strongly linked to decreased risk of cognitive impairment and therefore likely dementia,” Keenan told PsyPost. “The nutrients with these protective associations include vitamins (e.g., A, B, C, and E), minerals (e.g., copper, magnesium, selenium, and zinc), carotenoids (e.g., lutein, zeaxanthin, beta-carotene, and lycopene), lipids (e.g., omega-3 fatty acids), and fiber.” ³

After a meal, blood glucose levels rise, which raises insulin secretion from the pancreas simultaneously. Insulin causes glucose to deposited in the liver as glycogen; then, during the next few hours, when blood glucose concentration falls, the liver releases glucose back into the blood, decreasing fluctuations. Timing, contents, portions, and even the order of foods eaten determines the rise or spikes in insulin levels.

Glucose

Glucose transport into cells is made possible through protein carrier molecules; the rate of glucose/carbohydrate utilization is under the control of the rate of insulin secretion from the pancreas. Fats and cholesterol cannot dissolve in the blood and so are packaged with proteins, as called lipoproteins, for transport. ⁴

This glucose can then either be utilized immediately for the release of energy through glycolysis, a multi-step procedure to release energy in the form of ATP, or can be stored as glycogen(polysaccharide). Liver cells and muscle cells store large amounts of glycogen for later use. Glucose metabolism involves multiple processes, including glycolysis, gluconeogenesis, and glycogenolysis, and glycogenesis.

This balance of glucose and insulin is essential for maintaining stable energy levels and overall health. Glucose is a crucial energy source for your body. Here’s how it works:

1. Digestion and Absorption: Eating foods containing carbohydrates, the digestive system breaks them down into glucose. This glucose is then absorbed into your bloodstream through the intestines.
2. Insulin Release: As blood glucose levels rise, the pancreas releases insulin, a hormone that helps cells absorb glucose.
3. Energy Production: Once inside cells, glucose is used to produce energy through a process called cellular respiration. This energy powers various cellular functions and activities.
4. Storage: Excess glucose is converted into glycogen and stored in the liver and muscles for later use. When the body needs more energy, glycogen is converted back into glucose.
5. Regulation: Insulin helps regulate blood glucose levels by ensuring that cells take in glucose. If blood glucose levels drop too low, the pancreas releases another hormone called glucagon, which signals the liver to release stored glucose.

Cholesterol

Cholesterol is insoluble in the blood; it must be attached to certain protein complexes called lipoproteins in order to be transported through the bloodstream. Chemically, cholesterol is an organic compound belonging to the steroid family; its molecular formula is C27H46O. Cholesterol is essential to life; it is the starting material or an intermediate compound from which the body synthesizes bile acids, steroid hormones, and vitamin D. Cholesterol is vital for brain function and development, as it plays a key role in the formation of cell membranes and the production of myelin, a protective sheath that surrounds nerve fibers.

Cholesterol circulates in the bloodstream and is synthesized by the liver and several other organs; a precursor for important steroid hormones, including cortisol, aldosterone, estrogen, progesterone, and testosterone. The body tightly regulates cholesterol levels through a complex process involving cholesterol synthesis, absorption, and excretion. When dietary cholesterol intake increases, the body compensates by reducing endogenous cholesterol production, maintaining overall balance.

Phytonutrients

Flavonoids, also known as phytonutrients, are natural compounds that are commonly consumed in our everyday diet. Flavonoids are phytochemical compounds present in many plants, fruits, vegetables. Anthoxanthins, flavanones, flavanonols, flavans, chalchones, anthocyanidins, and isoflavonoids are the different subgroups of flavonoids of which 10,000 flavonoid compounds have been identified. Flavonoids are a group of plant compounds known for their vibrant colors and have numerous health benefits, such as:

1. Antioxidant Properties: Flavonoids help protect your body from oxidative stress by neutralizing free radicals, which can damage cells and contribute to aging and diseases.
2. Anti-inflammatory Effects: They have anti-inflammatory properties, which can help reduce inflammation in the body and lower the risk of chronic diseases.
3. Heart Health: Consuming flavonoid-rich foods like berries, apples, and citrus fruits can improve heart health by lowering blood pressure and reducing the risk of cardiovascular diseases.
4. Cancer Prevention: Some flavonoids have been shown to inhibit the growth of cancer cells and promote the death of cancerous cells.
5. Cognitive Function: Flavonoids may also support brain health and improve cognitive function, potentially reducing the risk of neurodegenerative diseases.

Types of Polyphenols

More than 8,000 types of polyphenols have been identified. They can be further categorized into 4 main groups:

1. Flavonoids. These account for around 60% of all polyphenols. Examples include quercetin, kaempferol, catechins, and anthocyanins, which are found in foods like apples, onions, dark chocolate, and red cabbage.
2. Phenolic acids. This group accounts for around 30% of all polyphenols. Examples include ferulic and chlorogenic acids in coffee and cereal grains.
3. Polyphenolic amides. This category includes capsaicinoids in chili peppers and avenanthramides in oats.
4. Other polyphenols. This group includes stilbenes in grapes and berries, resveratrol in red wine, ellagic acid in berries, curcumin in turmeric, and lignans in flax seeds, sesame seeds, and whole grains.

The amount and type of polyphenols in foods depend on the food, including its origin, ripeness, and how it was farmed, transported, stored, and prepared.

Diurnal Cycle

The diurnal cycle, also known as the circadian rhythm, significantly influences metabolism. These rhythms regulate cellular, physiological, and behavioral processes in coordination with environmental cues. "The circadian clock, a highly specialized, hierarchical network of biological pacemakers, directs and maintains proper rhythms in endocrine and metabolic pathways required for organism homeostasis. The clock adapts to environmental changes, specifically daily light-dark cycles, as well as rhythmic food intake. Nutritional challenges reprogram the clock, while time-specific food intake has been shown to have profound consequences on physiology. Importantly, a critical role in the clock-nutrition interplay appears to be played by the microbiota. The circadian clock appears to operate as a critical interface between nutrition and homeostasis, calling for more attention on the beneficial effects of chrono-nutrition."³

Timing of food intake can rewire temporal coordination of metabolism and gene expression; Thus, food restriction, exercise, or energetic stressors that influence the temporal regulation of metabolism are relevant for glycemic control and weight loss in type 2 diabetes and obesity.⁵

UNDER CONSTRUCTION !!!!

triglycerides is from the sugar we eat, LDL is from the fat we eat, -- Robert Ludwig, MD.

Cellular Respiration -- ABCWorksheet.com

As a result, we must exhale carbon dioxide. Contrary to popular belief, the urge to breathe is primarily to rid the body of excess carbon dioxide (CO2) from the bloodstream. and

Foot Notes