Metabolism is defined the sum of all chemical reactions which occurs and are involved in sustaining life of a cell, and thus an organism. Metabolism is of the following two types: catabolism and anabolism. In catabolism, molecules break down producing energy
During anabolism, synthesis of essential compounds needed by the cells are produced (such as DNA, RNA, and protein synthesis).
Bioenergetics describes the metabolic pathways by which a cell obtains energy. Nutrition science studies the relation between food substance and living things. The study deals with:
1) Body requirements of various substances.
2) The function of various substances in body.
3) The amount of the substances needed.
4) The lower levels below which health gets affected.
The food which we eat supplies energy (calories) and supplies essential chemicals which the body cannot synthesize by itself. Food provides substances which are essential for building and repair of body tissues. Food provides substances for efficient functioning of the body.
Energy is trapped in complex chemical compounds and in nutrients. These compounds are broken down to obtain energy. Humans obtain energy from carbohydrates, lipids and proteins. The chemical energy in these molecules is transformed into thermal, kinetic, and other chemical forms.
NUTRIENTS OF HUMAN METABOLISM
Carbohydrates, lipids, and proteins serve as a fuel for the human body. The nutrients are broken down into smaller pieces in the alimentary tract and are absorbed into the blood. This makes it possible for tissues and cells to transform the chemical energy of digestive end products into useful work. The majority of the absorbed products contain monosaccharides, glucose, monoacylglycerol, long chain of fatty...
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...amino acids by cells. All cells do not have proper enzyme machinery and compartments to use all the 3 molecules. Red blood cells are cannot oxidize fatty acids and amino acids as they are devoid of mitochondria. The type of substrate used by the cell changes according to the physiological situation of the cell. Such situations are commanded by different signals. The hormones exert powerful effects which can change the whole cell metabolic profile. Therefore, one should know all the metabolic pathways which control the energy conversion and regulation.
REFERENCES
Blaxter, K. (1989). Energy metabolism in animal and man. Cambridge University Press.
Andrea, T. Da Poian., & Tatiana, El-Batcha. Nutrient Utilization in Humans: Metabolism Pathways. Retrieved from
http://www.nature.com/scitable/topicpage/nutrient-utilization-in-humans-metabolism-pathways-14234029
Animal metabolism consists of the utilization of nutrients absorbed from the digestive tract and their catabolism as fuel for energy or their conversion into substances of the body. Metabolism is a continuous process because the molecules and even most cells of the body have brief lifetimes and are constantly replaced, while tissue as a whole maintains its characteristic structure. This constant rebuilding process without a net change in the amount of a cell constituent is known as dynamic equilibrium (Grolier1996). In the combustion of food, oxygen is used and carbon dioxide is given off. The rate of oxygen consumption indicates the energy expenditure of an organism, or its metabolic rate (Grolier1996).
Mader, S. S. (2010). Metabolism: Energy and Enzymes. In K. G. Lyle-Ippolito, & A. T. Storfer (Ed.), Inquiry into life (13th ed., pp. 105-107). Princeton, N.J: McGraw Hill.
Food influences us in many ways. These ways include food as nutrition, how we see nature, in our culture, it is a social good, it is a source of inspiration in an artful way, food is a primordial desire, and food influences our spirituality. Food is a substance that derives from the environment in the form of plants, animals, or water. The primary function of food is to provide nourishment to an organism. It is a basic necessity that all humans want and need in order to live. Food has an intrinsic value separate from its instrumental value to satisfy human needs. Food has a significant impact on a culture. Each society determines what is food, what is acceptable to eat, and when certain things are consumed. Food is the object of hunger
Energy comes from all the foods and drinks you eat. Things like carbohydrates, proteins and fats are mainly the macro-nutrients.
Our chicken sandwich has, by now, been broken down into digestible nutrients. The pancreatic juices have broken down the carbohydrates in the bread into monosaccharides (such as glucose and galactose) which leave the enterocyte by facilitated diffusion and enter the rich network of capillaries. They are transported in the blood stream and cross into the cytoplasm by Na+ cotransporters. Amino acids are moved to the circulation by facilitated diffusion. Lipids from the butter are broken down into fatty acids by lipases and are then absorbed across the cell membrane into the cytosol where they are reassembled into lipoprotein particles called chylomicrons. These are carried through lymphatic channels and into the circulation via the thoracic duct. The bloodstream carries simple sugars, glycerol, amino acids, and a number of salts and vitamins to the liver. The lymphatic system, a network of vessels that carry white blood cells and lymph fluid throughout the body, absorbs fatty acids and
During catabolism, chemical energy such as ATP is released. The energy released during catabolism is released in three phases. During the first phase, large molecules are broken down. These include molecules such as proteins, polysaccharides, and lipids. These molecules are converted into amino acids and carbohydrates are converted into different types of sugar. The lipids are broken down into fatty acids
The absorptive state is the time during and right after eating a meal. The absorptive state lasts for four hours, during and after each meal. During this state glucose is the most important energy fuel. Amino acids and fats are used to form degraded protein, and small amounts are used to provide ATP. Metabolites are transformed to fat if they are not used for anabolism. Glucose is formed by the conversion of fructose and galactose, which are stored in the liver from the entrance of monosaccharides. Glucose is released into the blood, or converted to glycogen and fat. Some glucose enters the liver and is used for energy, and any that is not used will be stored in skeletal muscle as glycogen or in adipose cells as fat. Liver, skeletal muscle, and adipose cells use triglycerides as their primary energy source. Amino acid are also used by the liver to synthesize plasma proteins. Essentially all of the events that occur in the absorptive state are directed by insulin.
Enzymes are proteins that help speed up chemical reactions. Some enzymes associated with carbohydrate breakdown are sucrose, lactose, maltase, and amylase. They aid in turning carbohydrate into glucose. The body uses glucose for energy, especially within the cells. Lipids or fats must be emulsified by bile found in the liver, and will be broken down into fatty acids and glycerol, and the body is able to absorb them. The enzyme associated with lipid breakdown is lipase. Protein that is ingested use the enzymes proteases and peptidases to help break up the protein and make amino acids in the
Protein have connection with amino acid to help in functions of: skin, muscle, hair and bones
When something gives us energy, it means more than to just give us the required power to work or move along for such a specific task. In biological terms, it means to have your energy be transported through your body and placed by cells into biomolecules. Biomolecules such as lipids and carbohydrates. It then stores that energy in our body.
Our metabolism, “the totality of an organism’s chemical reactions”, manages energy usage and production of cells. We use energy constantly and our metabolism breaks down food through complex chemical reactions into energy our cells
Nutrition is the process of obtaining and consuming the right nutrients you need in order to grow and survive. These nutrients consist of water, protein, carbohydrates, vitamins and minerals, and fats. What you choose to eat has a significant impact on your well being, growth and overall health. Bad nutrition can lead to lifelong consequences such as Diabetes, High blood pressure, Obesity, Cardiovascular disease and even some Cancers. A healthy diet helps people manage a desirable body weight and composition that allows them to do their daily mental and physical activities (Youdim 1). If you eat the correct meals it provides energy and even helps boost your immune system. There are many examinations available to you to check if you’re on the
Liver is the principal site for protein metabolism. Although the liver plays a vital role in carbohydrate and fat metabolism, its function in protein metabolism is of critical importance, as the failure to do so for more than a few days can result in death. This includes deamination and transamination of amino acids, urea formation to remove ammonia from body fluids, formation of approximately 90% of all plasma proteins, and synthesis of non-essential amino acids (Donohue Jr, 1996).
Fermentation is an anaerobic process in which fuel molecules are broken down to create pyruvate and ATP molecules (Alberts, 1998). Both pyruvate and ATP are major energy sources used by the cell to do a variety of things. For example, ATP is used in cell division to divide the chromosomes (Alberts, 1998).
...ts. It is important to understand which substances need to be consumed more than others and also why the body needs to consume a substance. Proper diet and nutrition is a vital component to a long and healthy life.