Proteins in Human Body

Protein are the main building blocks of the tissues of the body. The proteins are made up of smaller molecules called amino acids.

Once consumed (eaten) a protein is digested into the smaller amino acids and transported to the all the cells of the body where the amino acids can be put back together to make the proteins the body needs.

The human body contains thousands of different proteins, each with a specific function determined by this unique shape.

Most proteins the body makes function as structural proteins. Muscle tissues and connective tissues are mainly composed of proteins.

Collagen, which appears microscopically as a densely packed long rod, is the most abundant protein in mammals and gives skin and bone their elastic strength.

Hair and nails are made of keratin, which is another dense protein made of coiled helices.

Some proteins have an extremely important function by serving as enzymes.

Enzymes make biological chemistry efficient and less wasteful of energy.

The digestive system produces digestive enzymes whose function is to break down food into its chemical constituents.

Amylase is an enzymes that is involved in the breakdown of the polysaccharide starch into the monosaccharide glucose.

Protein can be involved in the Immune Response Mechanism and serve as carrier or transport molecules and also participate in the translation of DNA.

About half the dietary protein that consume each day goes into making enzymes, the specialized worker proteins that do specific jobs such as digesting food and assembling or dividing molecules to make new cells and chemicals substances.

To perform these functions, enzymes often need specific vitamins and minerals.

Obviously, the new born animal needs lots of proteins for growth and maturation.

The genes of DNA decide which amino acids (obtained from digestion) will go on to make a protein the cell needs for whatever structure or function requirement.

Dietary protein is one of three sources that contributes amino acids to the amino acid pool. The other two are protein turnover and biosynthesis of amino acids in the liver.
Proteins in Human Body

Polymer Materials and Their Barrier Functions in Food Packaging

Polymers, more commonly known as plastics, are among the most widely used materials in modern food packaging. Their popularity stems from their ability to act as effective barriers that control the movement of gases, vapors, and moisture. These barrier properties are essential for preserving the quality, safety, and shelf life of many food products. Because of their versatility, polymers have increasingly replaced traditional packaging materials such as metal, glass, and paper. Lighter in weight, easier to shape, and often more cost-effective, plastics offer superior functionality across a wide range of applications.

A polymer’s permeability—its tendency to allow substances to pass through—depends on several key molecular characteristics. Free volume within the plastic allows small molecules to move more easily, while crystallinity makes the structure tighter and less permeable. Tacticity, or how side groups are arranged along the polymer chain, also influences barrier strength. Additional factors such as cross-linking, molecular orientation, and the thickness of the material play important roles in determining how well a polymer can keep moisture in and contaminants out.

Food-grade polymers appear in many forms. Thin films are used for wrapping snacks, produce, and baked goods, while more rigid plastics serve as bottles for beverages or cartons for dairy products. Regardless of form, a major requirement is effective protection—preventing food from drying out while blocking the entry of unwanted odors, environmental gases, or pollutants.

Some of the most common plastics in food packaging include polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). Each offers a different combination of flexibility, clarity, strength, and cost. However, one challenge with plastic packaging is migration: small amounts of unreacted monomers or additives may slowly move from the packaging into the food, especially when exposed to heat or prolonged storage.

For applications demanding the highest barrier performance, specialized polymers such as polyvinylidene chloride (PVDC) and ethylene vinyl alcohol (EVOH) are widely used. These materials excel at blocking oxygen and moisture, making them essential in products where freshness and extended shelf life are critical.
Polymer Materials and Their Barrier Functions in Food Packaging

The Importance of Carbohydrates in Human Nutrition

To perform its daily physiological functions and maintain a constant internal temperature despite environmental fluctuations, the human body requires a steady supply of energy. Among the three main macronutrients—carbohydrates, proteins, and fats—carbohydrates are the body’s most efficient and readily available energy source. They typically provide about 45% of the total energy in developed nations and up to 85% in developing countries, reflecting their affordability and accessibility worldwide.

Carbohydrates are the most widely distributed organic compounds on Earth, forming the bulk of foods such as grains, legumes, fruits, and tubers. These foods are easy to cultivate, inexpensive, and provide nourishment to a large portion of the global population. Nutritionally, carbohydrates include sugars, starches, dextrins, and glycogen, each playing a unique role in metabolism and food quality.

Beyond nutrition, carbohydrates also influence the flavor, color, texture, and sweetness of foods. Their humectant (moisture-retaining) and plasticizing properties make them vital in food processing, preserving freshness and enhancing sensory appeal.

Nutritional guidelines generally recommend that carbohydrates should make up at least 55% of daily caloric intake, with proteins contributing 10–12% and fats less than 30%. Historically, human diets have contained 40–80% of total energy from carbohydrates. However, with rising income levels and the popularity of high-fat Western diets, carbohydrate consumption—especially from starch—has declined, raising health concerns such as obesity and cardiovascular disease.

Starch, the main digestible plant polysaccharide, remains the major carbohydrate in the human diet, primarily derived from cereals, rice, and potatoes. In the body, carbohydrates serve as the preferred fuel for the brain and nervous system, which rely heavily on glucose to function properly. Stable blood glucose levels are therefore crucial for mental performance, concentration, and overall well-being.

Chemically, carbohydrates consist of carbon, hydrogen, and oxygen—typically following the empirical formula Cn(H₂O)n. This structure inspired the term “carbohydrate,” meaning “hydrate of carbon.” Their solubility and reactivity stem from hydroxyl groups and carbonyl components, which contribute to their versatile biological roles.

In summary, carbohydrates are not only a primary energy source but also essential for maintaining health, supporting metabolism, and enhancing food quality—making them a cornerstone of the human diet.
The Importance of Carbohydrates in Human Nutrition

Essential Functions of Minerals in the Human Body

Minerals perform essential roles in the human body, broadly categorized into two main functions: building body tissues and regulating physiological processes. Structurally, minerals such as potassium, sulfur, phosphorus, and iron are vital components of soft tissues, contributing to cellular function and metabolic activity. Calcium, phosphorus, magnesium, and fluorine are key constituents of bones and teeth, with calcium alone comprising 99% of the mineral content in bones. Inadequate intake during growth can result in stunted development and compromised skeletal integrity.

Sodium, primarily found in extracellular fluid, is the chief cation responsible for maintaining osmotic pressure, fluid balance, and pH homeostasis. Though less abundant in intracellular fluid and bone, sodium still contributes to these vital functions. The electrochemical gradient established by the separation of sodium and potassium across cell membranes is the basis of nerve impulse transmission and muscle contraction.

Minerals also regulate various biochemical processes. Iodine is essential for the synthesis of thyroxine, a hormone controlling metabolism. Chromium enhances insulin activity, while iron forms the core of hemoglobin, facilitating oxygen transport. These elements are crucial to hormone production and enzymatic activity, with deficiencies leading to metabolic disorders such as hypothyroidism, anemia, and insulin resistance.

Calcium also functions as a catalyst in blood clotting, while zinc and magnesium serve as cofactors in hundreds of enzymatic reactions. Many minerals assist in the absorption of nutrients and the metabolism of macronutrients, further influencing energy production and cellular health.

Dissolved minerals maintain nerve function, muscle contraction, and the acid-base balance of body fluids. They also regulate vital signs such as respiration, heart rate, and blood pressure. When deficient, mineral imbalances may cause clinical conditions, which are often reversible with dietary correction or supplementation. Additionally, their biochemical properties enable minerals to be harnessed in food processing, improving nutritional content and preservation.
Essential Functions of Minerals in the Human Body

The Essential Role of Protein Molecules in Living Systems

Proteins are fundamental macromolecules that serve as major structural and functional components of living organisms. Composed of amino acids linked by peptide bonds, proteins exhibit immense diversity in structure and function, playing critical roles in virtually every biological process. Thousands of different proteins exist, each tailored to a specific function essential for maintaining life.

Classification of Proteins Based on Biological Functions
1. Enzymatic Proteins
Enzymes are specialized proteins that act as biological catalysts, dramatically increasing the rate of chemical reactions. Without enzymes, many vital biochemical processes, such as digestion and metabolism, would occur too slowly to sustain life. Enzymes such as amylase, lipase, and protease facilitate the breakdown of carbohydrates, fats, and proteins, respectively. Some enzymes accelerate reactions by more than a million times without being consumed in the process. Emerging research has also led to the development of artificial enzymes and enzyme-based therapies for metabolic disorders.

2. Transport Proteins
Transport proteins play a crucial role in moving essential molecules within the body. Hemoglobin, a protein in red blood cells, binds oxygen in the lungs and transports it to tissues. Similarly, albumin helps transport fatty acids, minerals, and hormones through the bloodstream. Another vital transport protein, transferrin, carries iron, which is essential for red blood cell production. Advanced research in nanotechnology is exploring synthetic transport proteins for targeted drug delivery.

3. Structural Proteins
Structural proteins provide mechanical support and strength to cells and tissues. Collagen, the most abundant protein in mammals, forms the structural framework of skin, bones, tendons, and ligaments. Keratin strengthens hair, nails, and the outer layer of the skin, while actin and tubulin support cellular shape and movement. The study of structural proteins has led to innovations in tissue engineering and regenerative medicine.

4. Hormonal Proteins
Hormonal proteins act as chemical messengers, regulating physiological processes to maintain homeostasis. Insulin, secreted by the pancreas, controls blood glucose levels, preventing diabetes. Other hormones, such as growth hormone and thyroid hormones, regulate metabolism, development, and reproduction. Advances in biotechnology have enabled the production of synthetic hormones to treat endocrine disorders.

5. Defensive Proteins
Defensive proteins play a pivotal role in the immune system. Antibodies, produced by white blood cells, recognize and neutralize pathogens such as bacteria and viruses. Complement proteins assist in immune responses by marking invaders for destruction. Recent developments in immunotherapy harness defensive proteins to combat cancer and autoimmune diseases.

6. Proteins as an Energy Source
Although carbohydrates and fats are the body’s primary energy sources, proteins can be utilized for energy in times of prolonged fasting or intense physical exertion. When necessary, proteins undergo catabolism to provide energy, though excessive protein breakdown can lead to muscle loss and metabolic imbalances.

7. Building and Maintenance of Body Tissues
Proteins are essential for tissue growth, repair, and maintenance. They contribute to muscle synthesis, wound healing, and cellular regeneration. Essential amino acids, obtained from dietary proteins, are crucial for producing new proteins required for these processes. Protein deficiencies can lead to weakened immunity, muscle wasting, and delayed recovery from injuries.

Conclusion
Proteins are indispensable molecules that perform diverse and vital functions in living organisms. From enzymatic catalysis to structural support, transport, defense, and hormonal regulation, proteins are involved in every aspect of biological activity. Ongoing research continues to uncover new protein functions and their applications in medicine, biotechnology, and health sciences. Ensuring an adequate protein intake through a balanced diet is crucial for overall health and well-being.
The Essential Role of Protein Molecules in Living Systems

The Role of Nutritional Supplements in Food Fortification

Nutritional supplements are a significant category of food additives, widely used to enhance the nutritional profile of processed foods. Breakfast cereals, for instance, often make extensive nutritional claims, largely due to the fortification with vitamins and minerals. This practice not only improves the dietary value of such foods but also helps in addressing common nutrient deficiencies in populations.

Many additives used in food fortification are essential vitamins and minerals, such as vitamin C (ascorbic acid), vitamin D, and iron. These micronutrients are added to various staple foods, including milk, flour, cereals, and margarine, to compensate for dietary gaps, replace those lost during processing, and extend shelf life. For example, vitamin D is added to milk to prevent rickets, while folic acid is incorporated into flour to reduce neural tube defects in newborns. Fortification programs have been instrumental in reducing malnutrition-related diseases worldwide.

In addition to nutritional enhancement, food additives serve functional roles such as moisture control, thickening, and improving texture and appearance. Stabilizers, emulsifiers, and preservatives are commonly used to maintain consistency and prolong shelf stability. For instance, lecithin, a common emulsifier, prevents separation in processed foods, while ascorbic acid acts as an antioxidant to prevent spoilage.

To ensure safety and transparency, food additives are systematically regulated. Each additive is assigned a unique identification number, facilitating international standardization and consumer awareness. In Europe, these numbers are designated as E numbers, a system managed by the Codex Alimentarius Commission, an organization established by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) in 1963. The Codex Alimentarius provides a framework of international food standards to protect consumer health and ensure fair trade practices. For example, aspartame, a widely used artificial sweetener, is labeled as E951, while monosodium glutamate (MSG), a common flavor enhancer, is coded as E621.

Currently, estimates suggest that between 2,000 and 20,000 different additives are incorporated into processed foods. These include preservatives, stabilizers, conditioners, thickeners, colorings, flavorings, sweeteners, and antioxidants. While many additives enhance food safety and nutritional value, ongoing research continues to evaluate their long-term health effects, ensuring that regulatory bodies adapt to new scientific findings.

With increasing consumer awareness and regulatory oversight, food additives, including nutritional supplements, remain a crucial part of the modern food industry, balancing health benefits with safety and functionality.
The Role of Nutritional Supplements in Food Fortification

Essential Minerals for Optimal Body Function

The human body is a marvel of electrical activity, with electrolytes acting as the conductive 'wires' facilitating this internal electricity. Among the crucial electrolytes, cobalt, copper, fluorine, magnesium, and sulfur play indispensable roles in maintaining bodily functions and overall health.

Magnesium, a paramount mineral, holds a significant place as a cation in the body. While abundant overall, its intracellular concentration rivals that of potassium. Crucially, magnesium acts as a cofactor for numerous cellular enzymes, facilitating vital processes such as muscle contraction and relaxation. Adequate magnesium stores are vital for maintaining electrolyte balance, fundamental for optimal health. Although deficiency is rare due to its presence in various foods like vegetables, cereals, and nuts, beverages like coffee, tea, and cocoa also contribute to magnesium intake.

Sulfur, integral to all body proteins, primarily resides in sulfur-containing amino acids such as methionine and cysteine. This elemental relationship extends to crucial end products like glutathione and taurine, which play vital roles in immune function. Furthermore, sulfur's presence in certain vitamins is essential for enzyme function. Foods like meats, fish, cheese, eggs, and beans serve as excellent sources of sulfur. Notably, research on the allylsulfur compounds in garlic showcases potential antithrombotic and anticancer properties.

Fluorine's role in promoting mineral precipitation, particularly in dental health, underscores its importance. By aiding in the formation of apatite, fluoride helps protect teeth from cavities. While drinking water serves as the primary source of fluorine, fish also contribute to its intake. However, caution is necessary as high concentrations of fluorine can be toxic.

Copper, though required in trace amounts, is indispensable for various enzyme systems and tissue functions. Its presence in enzymes contributes to antioxidant activity, electron transport, and biosynthesis of vital proteins like collagen. Conversely, excess copper can lead to disorders like Wilson disease, where abnormal copper metabolism results in toxic accumulation in organs. Rich dietary sources of copper include fruits, beans, peas, eggs, and liver.

Cobalt, found primarily in vitamin B12, is essential for bone marrow function and red blood cell maturation. Excessive cobalt intake can lead to polycythemia, an overproduction of red blood cells. Additionally, cobalt plays a crucial role in maintaining a healthy nervous system. While dietary deficiency is rare due to its presence in various foods, excess cobalt can have toxic effects.

In conclusion, these minerals are not merely components but essential catalysts for a multitude of physiological processes. Their presence in adequate amounts is vital for maintaining optimal health, highlighting the importance of a balanced diet rich in diverse nutrients. Through ongoing research and understanding, harnessing the potential of these minerals can pave the way for improved health outcomes and well-being.
Essential Minerals for Optimal Body Function

Calcium Importance and Absorption

Calcium stands as one of the 21 vital elements essential for human well-being, and its health benefits do not materialize in isolation; rather, its effectiveness hinges on maintaining adequate levels of vitamin D.

Two categories of calcium are discernible: one tightly bound within bones and another more easily accessible type located on the bone surface.

The skeletal framework serves as a reservoir of minerals for the body, with 99% of the body's calcium stored in bones and teeth, providing structural support. The remaining 1% is dispersed in intracellular and extracellular fluids, allowing the body to draw from skeletal reserves during periods of low blood calcium levels and replenish them as necessary.

A continuous supply of calcium is vital throughout life, particularly during growth phases, pregnancy, and lactation (breastfeeding).

Calcium plays a pivotal role in the secretion of hormones and enzymes, facilitates the efficient functioning of neurotransmitters, and is indispensable for muscle and blood vessel contraction.

In the bloodstream, calcium concentration typically ranges from 2.25 to 2.5 mmol. Approximately 40-45% of this quantity binds to plasma proteins, 8-10% forms complexes with ions like citrate, and 45-50% exists as dissociated free ions.

Around 10-40% of dietary calcium is absorbed in the small intestine with the aid of vitamin D, and the body augments calcium absorption in the event of deficiency.
Calcium Importance and Absorption

What are vitamins?

A vitamin is an organic compound, which means that it contains carbon. It is also an essential nutrient that the body may need to get from food. It presents in minute amounts in natural foodstuffs. Vitamins are needed for normal cell function, growth, and development.

In 1912, a Polish chemist named Casimir Funk, proposed that disease may be caused by a missing ingredient that should be in the diet. The major period of discovery began in the early nineteenth century and ended at the mid-twentieth century.

Vitamins are essential dietary substance needed in small amounts to regulate chemical reactions in the body. They include vitamins A, C, D, E, and K, choline, and the B vitamins (thiamin, riboflavin, niacin, pantothenic acid, biotin, vitamin B6, vitamin B12, and folate/folic acid).

Vitamins are team players – they help other nutrients work better, e.g., vitamin D enhances the absorption of calcium, vitamin C is needed to absorb iron and B vitamins work together in cells.

Vitamins needed to make enzymes and hormones – important substances of the body use to make all the many chemical reaction for the body to live.

Vitamins are important for proper growth and maintenance of good health, but they appeared to possess no greater properties beyond their basic chemical function.

Vitamins do indeed participate in the chemical reactions that release energy from carbohydrates, and proteins, and fats, but contain no inherent energy themselves.

A vitamin deficiency occurs when human body do not get enough of a certain vitamin. Vitamin deficiency can cause health problems.

Not eating enough fruits, vegetables, beans, lentils, whole grains and fortified dairy foods may increase the risk for health problems, including heart disease, cancer, and poor bone health.

Vitamins are generally categorized into the following types: fat soluble and water soluble. Solubility confers on vitamins many of their characteristics. It determines how they are absorbed and transported around by the bloodstream, whether they can be stores in the body, and how easily they are lost from the body.
What are vitamins?

Carbohydrates: Functional properties in food

Carbohydrates are made of building blocks of sugars, and can be classified according to how many sugar units are combined in their molecule. Glucose, fructose and galactose are examples of single-unit sugars, also known as monosaccharides.

People get their carbohydrates from food. All plants contain carbohydrates, which typically represent a significant portion of people’s dietary intake. Carbohydrate constituents of the food undergo a variety of chemical changes during mechanism, heat or cold processing of foods.

*Nutrition. Eating foods high in fiber, like fruits, vegetables and whole grains, can also help with regular bowel movements, minimize constipation-related issues and may help lower cholesterol and blood sugar.Dietary fiber plays a role aiding in weight reduction by promoting a feeling of fullness.

*Flavor and color in food production. Carbohydrates play a critical role in developing flavor and color in food products. The Maillard reaction and caramelization are two primary mechanisms responsible for this.

*Release and retention of the flavor compounds. These effects depend on many factors such as the physicochemical characteristics of the aroma compounds, type of carbohydrates and concentration of carbohydrate

*Caramelization. Caramelization creates one of the most naturally delectable combinations of sweet, savory, and bitter flavors. Caramelization is a type of non-enzymatic browning reaction. As the process occurs, volatile chemicals are released producing the characteristic caramel flavor. The reaction involves the removal of water (as steam) and the breakdown of the sugar.

*Sweetening. Sweet tasting carbohydrates like sucrose or glucose are multifunctional food ingredients. Different sugars vary in sweetness. Fructose is almost twice as sweet as sucrose and sucrose is approximately 30% sweeter than glucose.

*Texturing. Carbohydrates provide a range of desirable textures from crispness to smooth, soft gels.

*Plasticizing action and humectancy. Carbohydrates are hydrophilic to different degrees, depending on their structures which governs their plasticizing action and humectancy.
Carbohydrates: Functional properties in food

Honey - flavorful sugar syrup

Honey, the natural sweet substance, is produced by honey bees — Apis mellifera — primarily from plant nectars. A small fraction of honey is produced from something called honeydew.

Honey is gathered by bees to feed young bees. Honey also used as energy source for their workers.

Most plants don’t begin to produce significant amounts of nectar until they have a chance to warm up in the morning sun. Once warm, the nectar begins to flow. When a worker bee visits a flower, it drinks it up the nectar with her special, tube-shaped tongue called a proboscis, to suck the nectar from the flower. Then part of the honey goes to the stomach to be used as food, but a large portion goes to a special organ called a honey sac.

The honey sac stores nectar and incorporates enzymes to prepare it for its long journey to becoming honey. Once back in the hive, the nectar is regurgitated and passed on to other worker bees. The nectar is constantly being enriched with enzymes, and the excess water is partially withdrawn.

The transformation from nectar to honey involves many steps, which are collectively called ‘ripening.’ The processed nectar is then deposited into a honeycomb cell in the form of a droplet. During the ripening process, a significant amount of water evaporates from the honey, giving it a syrupy consistency.

The nectar is greatly concentrated and stored in wax cells, thousands of which form the honeycomb. In natural honeybee colony, honey serves as food for the bees though the winter when plants are dormant.

The bioactive components of honey are affected by the flora from which it is produced and by geographical variations. Phenolic compounds promote, among other activities, high antioxidant action, being capable of minimizing intracellular oxidative damage associated with cellular aging, apoptosis and neurodegenerative diseases.

It has been long recognized as one of the finest of nature’s energy foods. Honey may be one of the most effective ways to consume carbs before exercise. The lower glycemic index profile of honey is an important consideration for athletes.

Most of the water in the nectar evaporates, resulting in honey, which is thirty five to forty percent fructose, thirty to thirty five percent dextrose, seventeen to twenty percent water and small amounts of enzymes, etc.
Honey - flavorful sugar syrup

Hyaluronic acid in human body

Among food that are rich with hyaluronic acid including: bone broth, citrus fruits, tofu, kale, almonds, edamame, sweet potatoes, nut and seeds.

In human skin, hyaluronic acid has the ability to bind water in the tissue. However, as the amount of hyaluronic acid decrease with age, les water is bound, making the skin look older, less elastic and less resilient.

Hyaluronic acid has many functions, but primarily it holds water in the tissues by binding water molecules to cells and tissues.

This helps to provide the medium need for numerous body process and molecular transport. The large amount of fluid that is held by the polymers permits diffusion of solutes between capillaries and cells.

In the synovial cavity, the viscosity of the synovial fluid assists in lubrication of joints, which acts to dampen shock.
Hyaluronic acid in human body

Basic unit of protein and its function

The word protein is derived from Greek word, “proteios” which means primary. As the name shows, the proteins are of paramount importance for biological systems. Proteins are biochemical molecules consisting of polypeptides joined by peptide bonds between the amino and carboxyl groups of amino acid residues.

Proteins are made up of hundreds or thousands of smaller units known as amino acids. Most organisms use 20 naturally-occurring amino acids to build proteins. The linear sequence of the amino acids in a protein is dictated by the sequence of the nucleotides in an organisms’ genetic code. Amino acids can combine to form long linear chains known as polypeptides. Each type of polypeptide chain has a unique amino acid sequence.

The sequence of amino acids determines each protein’s unique 3-dimensional structure and its specific function such as catalysis of biochemical reactions, mechanical support and immune protection, movement, transport of ligand, transmits nerve impulses, and control growth and differentiation.

The proteins function to regulate specific steps in metabolism – one step, one protein. Hence, many proteins are needed.

The polypeptide must fold into a specific three-dimensional structure before it can perform its biological functions. The function of all proteins depends on their ability to specifically interact with other molecules. Such specificity is possible because polypeptides with different amino acid sequences fold into different tertiary structures.

Proteins are not entirely rigid molecules. They undergo conformational changes upon ligand binding. Each kind of protein evolved to interact with a specific molecule or ligand. For example, transport proteins (such as hemoglobin) bind to specific ligands (in this case oxygen) and transport the ligand to a site where it is needed. Hemoglobin, the transporter of oxygen is a tetrameric protein (alpha 2, beta 2), with each monomer having a heme unit. Binding of oxygen to one heme facilitates oxygen binding by other subunits.

Storage proteins such as myoglobin, another oxygen-binding protein, allow the cell to store higher concentrations of the ligand than otherwise would be possible.

Catalytic proteins— the enzymes—convert the ligands into other molecules. They act as biochemical catalysts. The first step in enzymatic catalysis is the binding of the enzyme to the substrate. This, in turn, depends on the structural conformation of the active site of the enzyme, which is precisely oriented for substrate binding

Many proteins have structural or mechanical functions. Structural proteins interact with specific molecules, often endowing the bound molecules with special biological properties. For instance, one class of proteins, the histones, binds to DNA to form compact nucleoprotein structures called nucleosomes, while a second class of proteins combines with RNA to form the ribonucleoprotein complex known as the ribosome.

Structural proteins collagen is the most abundant protein in mammals and is the main fibrous component of skin, bone, tendon, cartilage and teeth.

Proteins are also important in cell signaling, immune responses, cell adhesion, and the cell cycle.
Basic unit of protein and its function

 

Roles and functions of mineral manganese in human body

Manganese is an essential nutrient for intracellular activities; it functions as a cofactor for a variety of enzymes, including arginase, glutamine synthetase (GS), pyruvate carboxylase and Mn superoxide dismutase (Mn-SOD).

Manganese also plays an essential role in regulation of cellular energy, bone and connective tissue growth, and blood clotting.

Humans maintain stable tissue levels of Mn. This is achieved via tight homeostatic control of both absorption and excretion. Only a small percentage of dietary manganese is absorbed. Manganese is used in energy production and is required for normal bone growth and for reproduction. In addition, it is used in the formation of cartilage and synovial (lubricating) fluid of the joints. It is also necessary for the synthesis of bone.

Too little dietary manganese causes impaired skeletal development and reproduction, abnormal carbohydrate and lipid metabolism, and movement disorders.

Manganese is essential for people with iron deficiency anemia and is needed for the utilization of vitamin B1 (thiamine) and vitamin E. Most of the blood manganese (~60%) is distributed in soft tissues, the rest is rapidly delivered to the liver (30%), kidney (5%), pancreas (5%), colon (1%), bone (0.5.%), urinary system (0.2.%), brain (0.1.%) and erythrocytes (0.0.2%).

Manganese works well with the B complex vitamins to give as overall feeling of wellbeing.

Manganese is an important cofactor for a variety of enzymes, including those involved in neurotransmitter synthesis and metabolism. Manganese aids in the formation of mother’s milk and is a key element in the production of enzymes needed to oxidize fats and to metabolize purines, including the antioxidant enzymes superoxide dismutase.

Enzymes containing manganese protect the body from harmful oxygen radicals, highly reactive oxygen containing molecules that can damage living tissues.

The richest food sources of manganese are nuts, bread and cereal products. The Adequate Intake of manganese for adult men and women is 2.3 and 1.8 mg/day, respectively, being the Tolerable Upper Intake Level for adults of 11 mg/day.
Roles and functions of mineral manganese in human body

Calcium in human bones

The name calcium is derived from latin word calas meaning lime was known as early as the first centuries when the ancient Romans prepared lime as CaO.

Calcium enters the body through the gastro-intestinal tract, is absorbed mainly in the upper small intestine and is excreted via the bowel, kidneys and skin.

There are two types of calcium. One type of calcium is tightly bound within the bone and the other more accessible type of calcium is found on the bone.

The skeleton serves as a bank of minerals for the body. 99% of the calcium in human body is stored in bones and teeth which support body structure.

Combines with phosphorus to form bones and teeth, making them hard and resistant to breaks and decay. High dietary calcium intake is necessary for infants, children and adolescents to get enough calcium for their bones and teeth to develop normally. Getting enough calcium early in life helps bones remain strong later in life.

During skeletal growth and maturation, i.e. until the age of the early twenties in humans, calcium accumulates in the skeleton at an average rate of 150 mg a day.

Without this calcium, bones will become weak. As they weaken, fractures and breakage can occur i.e., osteoporosis, in which the bones become porous and fragile because calcium is withdrawn from the bones and other areas faster than it is deposited in them.
Calcium in human bones

Hyaluronic acid: Functions and applications

In 1934, Karl Meyer and his assistant, John Palmer, described a procedure for isolating a novel glycosaminoglycan (GAG) from the vitreous of bovine eyes. They showed that this substance contained an uronic acid and an amino sugar but without sulfoesters.

The term hyaluronan is attributed Endre Balazs, who coined it to encompass the different form the molecule can take for example the acid form, Hyaluronic acid and the salts such as sodium hyaluronate, which form at physiological pH.

Hyaluronic acid is a typical mucopolysaccharide. It is a naturally occurring substance found in the spaces between the cells of body tissues in all animals. Hyaluronic also known as hyaluronan.

Hyaluronic acid is widely distributed in mammalian cells and tissue but is primarily found in synovial fluid, vitreous humor of the eye and loose connective tissue such as rooster comb, umbilical cord, dermis and arterial wall. It is also found in the capsular component of certain bacterial such as Streptococcus sp. and Staphylococcus sp.

Hyaluronic acid is synthesized in many cell types, but primarily in the plasma membrane of fibroblasts.

Its name is derived from hyaloids (vitreous) and uronic acid. Hyaluronic acid is a polyanionic natural polymer occurring as linear polysaccharide composed of glucuronic acid and N-acetylglucosamine repeats via a β-1,4 linkage.

Glycosaminoglycans – hyaluronic acid family, can be found in almost all living organisms that have joints and connective tissue.

Large polymers of hyaluronic acid form mesh that enables it to bind a large amount of water. In loose connective tissue such as binding of tissue fluid forms a jellylike matrix filling the space between capillaries and cells.

Hyaluronic acid has a wide range of applications with its excellent physicochemical properties such as biodegradability, biocompatibility, nontoxicity, and non-immunogenicity and serves as an excellent tool in biomedical applications such as osteoarthritis surgery, ocular surgery, plastic surgery, tissue engineering, and drug delivery.

Physiologically, hyaluronic acid has a role in several process including angiogenesis, extra cellular matrix, homeostasis, wound healing and the mediation of long-term inflammation.

It plays a key role in cushioning and lubricating the body and is abundant in the eyes, joints, and heart valves.
Hyaluronic acid: Functions and applications

Roles of fat in human body

Body fat stores are the major energy stores of the body and are important determinants of survival in starvation or undernutrition.

Human body require stores of energy and mechanisms to accumulate and release these stores in the short and long term. Fat, here taken to be triacylglyceride, is quantitatively the most important form of stored energy and is found in adipose tissue (AT).

Adipose tissue makes up a significant part of human bodies. Adipose tissue can also be found surrounding organs such as the liver, pancreas, kidneys and the heart, to some degree. It is also found in muscles and other areas of the body including part of the orbital cavities.

In chemistry, fat is a compound formed from chemicals called fatty acids. Fats are greasy, solid materials found in animal tissues and in some plants.

For most part, human did not require fat sources in their diets because the body can synthesize most of the fatty acids it needs from other constituents, including carbohydrate and protein.

Essential fat is that in bone marrow, heart, lungs, liver, kidneys, intestines, muscles and lipid-rich tissue of the central nervous system with roles other than energy storage.

Saturated and monounsaturated fatty acids are synthesized in the body for energetic, physiological, and structural functions, and they are present in many foods. The brain needs saturated fats, polyunsaturated fat, cholesterol, and a number of other fats.

Fats are also a component of cell membranes, vitamin D and sex hormones. Men have a central pattern of deposition, mainly on the trunk and abdomen. In women deposition is, characteristically, on the buttocks and thighs.

Some types of fats give cell membranes flexibility and help regulate the transfer of nutrients into and out of cells. While others serve as precursors to vitamin D and sex hormones, such as estrogen and testosterone.
Roles of fat in human body

Phospholipids: Food sources and functions

Phospholipids are molecules in which hydrophilic head group and hydrophobic acyl chains are linked to the alcohol. Phospholipids have an important participation in all living cell membranes, which act as the building block of cell membranes in all organisms.

Phospholipids are lipids containing phosphorus, a polar potion and non-polar potion in their structures. They are amphiphilic molecules that are in charge of controlling what goes in or out of the cell. In fact, they are the major structural constituents of all biological membranes, although they may be also involved in other functions such as signal transduction.

Phospholipids can be divided into three categories:
*Phosphatidic acids, lecithin, cephalins, etc
*Plasmalogens
*Sphinghomyelins

Phospholipids are widely distributed in animals and plants, and the main sources include vegetable oils (e.g. soybean, cotton seed, corn, sunflower and rapeseed) and animal tissues (e.g. egg yolk and bovine brain). In terms of production, egg yolk and soybean are the most important sources for phospholipids.

Phospholipids provide rigidity, signal transduction, energy to cells. Phospholipids such as lecithins are molecules of future food, medicine and cosmetic industry. Phospholipids are used in fat and oil refining and these are also used as carriers in drug and drug delivery system.
Phospholipids: Food sources and functions

Food additives: definition and concept

Food additives are not a new invention. Since early times, there has been a need to preserve food from one harvest to another and to improve the presentation and nutritional value of food. Additives such as salt, spices, and sulfites have been used since ancient times to preserve foods and make them more palatable.

Why adding food additives?
*Food production separated from areas of population concentration –preservatives
*Added for functional properties –color, flavor, texture, nutritional supplements etc
*Convenience foods –foods whose preparation labor removed from household to processor or manufacturer. eg flour, can of beans or soups, cake mix, githeri, chapos, pizzas, etc

Technological advances in food processing have increased the variety and use of these additives. Today, more than 2500different additives are intentionally added to foods to produce a desired effect.

When the food is to be stored for a prolonged period, use of additives and preservatives is essential in order to maintain its quality and flavor. The excess water in the foods can cause the growth of bacteria, fungi and yeasts. Use of additives and preservatives prevents spoiling of the foods due to the growth of bacteria and fungi.

Many modern products, such as low-calorie, snack, and ready-to-eat convenience foods, would not be possible without food additives. Food additives and their metabolites are subjected to rigorous toxicological analysis prior to their approval for use in the industry.

Some of the commonly used food additives and preservatives are aluminum silicate, amino acid compounds, ammonium carbonates, sodium nitrate, propyl gallate, butylated hydrozyttoluene (BHT), butylated hydroxyanisole (BHA), monosodium glutamate, white sugar, potassium bromate, potassium sorbate, sodium benzoate, etc.

Food additives: definition and concept

What are the roles of flavor in food?

Flavor is the main determinant or driver of consumer acceptance of a food product and also repeat purchase intent for a food product. Flavors are volatile organic chemicals. Most have simple, well-characterized structures with a single functional group (i.e., a chemically reactive subunit) and a low molecular weight.

 Impart target flavor attributes (aromatics) to formulated products that lack flavor

 Both natural and artificial flavors play an important role in making food and beverages taste good.

 Compensate for flavor deficits or defects e.g. frozen concentrated orange juice (FCOJ)

 Mask off-flavors e.g. functional foods

 Flavor is the most important quality of foods and beverages for determining consumer acceptability

 Compensate for flavor losses caused processing or storage e.g. thermal degradation, flavor fade due to flavor interactions

 Contributes and enhances flavor in carbonated, beverages, fruit drinks and dessert.
What are the roles of flavor in food?