Transport Proteins

Transport protein regulate the flow of substance including nutrient into and out of the cell. Transport proteins may function by acting as carrier or they may provide protein lined passages through which water soluble materials of small molecular weight may diffuse.

Other transport proteins move about in the body fluids, carrying nutrients and other molecules form one organ to another. Those that carry in the lipoproteins are examples.

Special proteins also can carry fat soluble vitamins, water-soluble vitamins and minerals.

One of the important transport proteins is hemoglobin, the iron-containing protein of blood, transport oxygen from the lungs to other parts of the body.

What is hemoglobin? Hemoglobin is the protein molecule in red blood cells that carries oxygen from the lungs to the body's tissues and returns carbon dioxide from the tissues to the lungs.

More than 98% of the oxygen in the blood is bound to hemoglobin molecules.

The iron contained in hemoglobin is responsible for the red color of blood. Hemoglobin is composed of a protein component called ‘globin’ and a red pigment component called ‘heme.’

What mean low or high hemoglobin? Low hemoglobin is referred to as being anemic.

There are many reasons for anemia. Some of the more common reasons are loss of blood (traumatic injury, surgery, bleeding colon cancer), nutritional deficiency (iron, vitamin B12, folate acid), bone marrow problems (replacement of bone marrow by cancer, suppression by chemotherapy drugs, kidney failure), and abnormal hemoglobin (sickle cell anemia).

Minerals deficiencies or imbalance in zinc, copper, vitamin A, B complex, and C cam also lead to anemia in females because of their diets or because of impaired absorption.

Anemia also can occur from poor red blood cell production. Such as when certain nutritional factors are missing, of I the bone marrow ahs been poisoned.

While for higher than normal hemoglobin levels can be seen in people living at high altitudes and also smokers.

Dehydration produces false high hemoglobin which disappears when proper fluid balance is restored.

That’s how important of transport protein to our body while other proteins transport molecules across cell membranes.
Transport Proteins

Enzymatic Proteins

The most varied and most highly specialized proteins are those with catalytic activity--the enzymes.

The word enzymes comes from the Greek root ‘enzymos’, which means “to cause change.”

There are hundreds of chemical reactions take place in human body every seconds. Nearly all of these reactions catalyzed by enzymes, which are large molecules that increase the rates of chemicals reactions without themselves undergoing any change.

What is enzyme? Enzyme is a protein that speeds up or catalyzes a chemical reaction. It is a protein catalyst employed by a cell to speed up metabolic reactions

Chemically, enzymes are like any catalyst and are not consumed in chemical reactions nor do they alter the equilibrium of a reaction.

That is enzymes cannot make a reaction take place that could not occur without them. Instead, they increase the reaction rate, sometimes making it many millions of times faster.
They cause reactions to take place faster by lowering the activation energy.

In general, enzymes function by lowering transition state energies and energetic intermediates and by raising the ground state energy.

Many thousands of different enzymes, each capable of catalyzing a different kind of chemical reaction, have been discovered in different organisms. Digestive enzymes hydrolyze the polymers in food.

As with any protein, each protein is actually produced as a long, linear chain of amino acids, which folds in a particular fashion to produce a three-dimensional product with a tertiary structure.

Each amino acid sequence produces a unique structure, which can have unique properties. Individual protein chains may sometimes group together to form a protein complex.

Enzymes are distributed according to the body’s need to catalyst specific reactions. A large number of protein-splitting enzymes are in the blood, ready to promote clotting.

Digestive enzymes, which also catalyst the hydrolysis of protein, are located in the secretions of the stomach and pancreas.
Enzymatic Proteins

Functions of protein

Protein molecules serve as some of the major structural elements of living systems.

There are thousands of different proteins with a specific functions.

Proteins have many different biological functions Proteins are classified according to their biological roles.

Enzymatic Proteins
Protein found in many enzymes. Enzymes are catalysts, meaning that they increases the rate of reactions e.g. food digestion , sometimes by more than a million times without being destroyed.

Enzymes necessary for the digestion of carbohydrates, fats, proteins.

Transport Proteins
It transport iron, fats, minerals and oxygen.

Structural Proteins
It serves as structural components of cells and organisms. It is the fundamental structural material of every cell in the body.

This functions depends on specific association of protein subunits with themselves as well as with other proteins, carbohydrates or others.

Hormonal Proteins
Hormones are chemical messengers secreted into the bloodstream by various organs, such as the liver. It regulates certain activities so that a constant internal environment is maintain.

For example insulin that plays a key role in regulating the amount of glucose in the blood. It is released from the pancreas in response to a rise in blood glucose levels.

Defensive Proteins
Protein used to build special white blood cells and antibodies as a part of the body’s immune systems for fighting invasion and infection by foreign substances.

Provide energy as last resort
Actually carbohydrates are the primary fuel source but in times of need, protein can be burned to supply energy.

Build and maintain the body
Proteins are used for building and maintaining body tissues. All this tissue must be repaired and replaced.
Functions of protein

Protein structure

Muscles are built from protein. We need to consume enough protein to allow our muscles to be healthy and perform work.

Generally, to survive we consume only several types of biological molecules: carbohydrates, lipids, and proteins (plus vitamins and the "non-biological" molecules: minerals and water)

The proteins are made up of smaller molecules called amino acids.

Biologically active proteins are polymers of consisting of amino linked by covalent peptide bonds.

Once consumed, 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.

Amino acids enter onto the general metabolic pathways which have been called anabolism and catabolism.

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

Some proteins have an extremely important function by serving as enzymes. Enzymes make biological chemistry efficient and less wasteful of energy. Still there are other "jobs" for proteins.

They can be involved in the immune response. Mechanism and serve as carrier or transport molecules and also participate in the translation of DNA.

A specific group of body’s proteins specializes in moving nutrients and other molecules into and out of cells. Some of these transport proteins act as pumps, picking up compounds on one side of the membrane and depositing them on the other.

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.

Some twenty two or more different amino acids are needed for the growth of new tissues, for the maintenance of established cellular constituents and for other metabolic requirements.

So it is remarkable that some proteins work together (with DNA/RNA) to make more proteins. Proteins, it might be said, more than any other molecule, are good at "re-booting" themselves.

Regarding the other nutrients taken with protein, apart from fat and carbohydrate it must also be accompanied by the full array of vitamins and minerals.

Other factor, protein quality, helps determine how well a diet supports the growth of children and the health of adults. Two factors influence protein quality; a protein’s digestibility and its amino composition.
Protein structure

Food sources of protein

During digestion, large molecules of proteins are broken down into simpler units called amino acids.

Amino acids are necessary for the synthesis of complete body proteins and many others tissue constituent.

Proteins are described as essential and nonessential proteins or amino acids. The human body requires approximately 22 amino acids in specific patterns for the synthesis of its proteins.

All the essential amino acids must be present simultaneously in the diet in order for the other amino acids to be utilized – otherwise, the body remains in negative nitrogen balance.

A lack of vital proteins in the body can cause problems ranging from indigestion to depression to stunted growth.

The body can make only 13 of the amino acids -- these are known as the nonessential amino acids.

They are called non-essential because the body can make them and does not need to get them from the diet.

The nine of these amino acids can be produced are called essential amino acids, and they must be supplied in the diet.

They are methionine, threonine, tryptophan, leucine, isoleucine, lysine, valine, phenylalanine and histidine.

If the protein in a food supplies enough of the essential amino acids, it is called a complete protein.

If the protein of a food does not supply all the essential amino acids, it is called an incomplete protein.

All meat and other animal products are sources of complete proteins. Spirulina contains all the essential amino acids. Soy comes close to being a complete plant protein.

These include beef, lamb, pork, poultry, fish, shellfish, eggs, milk, and milk products.

Protein in foods (such as grains, fruits, and vegetables) are either low, incomplete protein or lack one of the essential amino acids. These food sources are considered incomplete proteins.

To obtain a complete protein form incomplete protein foods, one must combine them carefully so that those foods that are low or missing an essential amino acid will be balanced by another food that supplies that amino acid.
Food sources of protein

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

Food Proteins

Protein constitutes 10-15 per cent of the energy in almost all human diets. It is also important in the structure of all cells in the body, as well as forming enzymes, molecules that transport substances in the blood and some hormones.

The problem of providing adequate protein for an expanding world population is a second only to the overall food problem.

Apart from their nutritional significance, proteins play a large part in the organoleptic properties of foods.

Proteins exert the controlling effect on a texture of foods from animal sources.

Foods in meat, poultry, dry peas and beans, eggs, ad nuts group and in the milk, yoghurt and cheese group contribute an abundance of high quality protein.

Two others, the vegetable group and the grains group, contribute smaller amounts of protein, but they can add up to significant quantities.

Protein content of wheat and flour is considered one of the best single indices of bread making quality.

Protein often occurs in foods in physical or chemical combinations with carbohydrates and lipids.

The glycol proteins and lipoproteins affect the rheological properties of food solution or have technical applications as edible emulsifiers.

During the heating (boiling, baking or roasting) the amino acid side chains are degraded or interact with other food component (e.g. lysine with reducing sugar) to give typical flavor.

Excessive heating may, on the other hand, reduce nutritive value.

The protein quality of the diet determines, in large part, how well children grow and how well adults maintain their health.

High quality protein provide enough of all the essential amino acids needed to support the body’s work, and low quality proteins do not.

Two factors influence protein quality – the protein’s digestibility and its amino acid composition.
Food Proteins

Food science and health

The optimum physical and mental functioning of the body is dependant on the nutritional quality of the foods it received.

Human have observed this since from beginning time and certain diets have been evolved as a result of these observations.

The analysis and planning of diets were not possible until food science become established to a degree and produce the basic information that made these activities possible.

Food science is an interdisciplinary field that evoked first from chemistry, then microbiology and medicine. Since then biochemistry, nutrition, toxicology, mathematics, physics, engineering, psychology, genetics, biotechnology and law have become integral part.

People do not eat nutrients, they eat food. In order to have a good understanding of the influence of diet on health and what the components of a healthy diet are, it is necessary to have some understanding food science.

From the knowledge acquired through the development of food science emerged conclusions that resulted in the classifications of foods into nutritional groups, representatives of which are considered to be necessary in all intake of a recommended minimum of protein, carbohydrates, vitamins, minerals, and so on.

Evidence of the links between diets and certain symptoms of ill health became easier to obtain as food science developed, and the potential of specific diets in correctives and preventive medicine has been gradually recognize and is now effectively practice.

Food scientists work in conjunction with nutritionists to develop standards for the optimal nutritional content of the diet and to determine how food processing and storage affects nutrients.

The important of this is to investigate how food formulation affects the bioavailability of nutrients. For example, ascorbic acid can increase the bioavailability of iron in the diet.

Food science is responding to present day and expected future health and safety trends.

The use of sciences such as biotechnology, genetic engineering, computer technology, microbiology and chemistry will allow the food scientist to help bring to the marketplace new foods that will meet the needs and desires of the consumer.

For example, convenience foods, low calories and low fat foods, quick methodologies such as gene probes as biosensors for detection of harmful microbes.

Food science will play significant role in future of the world’s food supply and the health and quality of life of its human inhabitants.
Food science and health

Food Science Impact to the Society

Food science is an interdisciplinary field that evolved first from chemistry, then microbiology and medicine.

The origin of food science is unclear but history reports that Egyptians, Greeks, and Romans were able to preserve a variety of foods on vinegar, brine, honey or pitch.

What is the impact of food science to the society? Perhaps the greatest impact of food science on society has come in the area of agriculture.

The earliest development of agriculture change nomadic societies to settles ones, because farming is more readily done on cultivated land that is already used as a farm.

Once the idea farming of the same land conceived, permanent shelter became more practical and the forerunners for modern house were built.

The protection of the house important enough to cause farmer to group together and to establish boundaries, the forerunners of modern day towns and cities were form.

What has the science done to increase population? In the first place, by machinery, fertilizers and improved breeds it has increased the yield per acre and the yield per man hour of labor.

Food science is responding to present day and expected future health and safety trends. The use of sciences such biotechnology, genetic engineering, computer technology, microbiology and chemistry will allow the food scientist to help bring to the marketplace new foods that will met the needs and desires of the consumer.

The discovery and utilization of scientific principles in food sciences, culminating in the preparation, packaging and distribution of process food, have provided a supply of safe, wholesome, and nutritious foods unknown before in history.

Food science will have a great impact at the manufacturing product and consumer levels, resulting in more efficient production of foodstuff and effecting improvements in both quality and “freshness.”

The multifactor nature of food is considered in the production of high quality, safe, nutritious food. Food science has been an integral part of society, The contribution of food scientists to the global world food supply is immense.
Food Science Impact to the Society

Food and diet

Food is the main tool for balancing the hormones and chemicals in the body and brain. Once food is broken down into glucose, amino acids and fatty acids, it travels through the bloodstream and feeds all the areas of the body.

It creates all the chemicals that control every system of the body. Food creates a positive or negative hormonal adjustment that lasts for up to six hours. Each meal readjusts the body chemicals.

The function of food is to keep us alive and healthy. The foods we eat derived from plants and animals. Foods are a complex mixture of many different chemical components. Food is that which nourishes the body.

Food components vary with the growth, maturation, harvesting or slaughtering, storage and handling of plant and animal parts used as food.

A balanced diet consists of adequate uncontaminated water, safe protein sources, starches (carbohydrates) fats, vitamins, minerals, and trace minerals.

A balanced diet consists of different types of food items includes a variety of foods.

The major aim is to ensure that all nutrient are supplied.
The problem with the modern food supply is that real food is transformed into processed chemicals, which effect the body’s biochemistry.

Meats are domesticated and filled with hormones, additives and antibiotics.

Grains and vegetables are contaminated with pesticides and sprayed with antibiotics.

Everyone needs safe water and food. It is time to learn to make the best food choices to control individual body chemistry.
Food and Diet

History of Food Science

History of Food Science
Food is any substance normally eaten or drunk by living organisms. The term food also includes liquid drinks. Food is the main source of energy and of nutrition for animals, and is usually of animal or plant origin. The beginning of food science development is questionable.

The term of food science is referred to interdisciplinary field that evolved first from chemistry, then microbiology, physics, engineering, psychology, genetics, biotechnology and law have become integral parts of this fascinating profession.

The history told us Roman realized, more than Greeks, Egyptians, or any other prior civilizations, that the agriculture was a prime concern for government.

The Romans were able to preserve a variety of foods by holding them in vinegar, honey or pitch. Some foods were dried either by sun or over the fire. These civilizations also produced cheeses or wine.

Food science became a legitimates profession following World War II. Prior to that, the vast majority of food is in the world were prepared locally and so consumers had no option but to visit butchers, bakeries, dairies, green grocers and other purveyors close to their homes and purchase mainly unbranded goods of questionable quality.

Technologies developed in the early and middle 20th century allowed the manufacturer and distribution of canned food, chilled and frozen foods and furnished consumers with electric driven refrigerators and freezers.
History of Food Science
Read also:
Food Science and Society
Food - The Largest of all Industries