Digestive System 2
Digestive System
Digestive System
Living organism require nutrients to survive, they acquire these nutrients by intaking food from the surrounding. The ingested food requires digestion so that it can be absorbed by the body and utilised effectively. Ingestion is defined as the consumption of food substances by an organism to meet its energy requirements needs. Ingestion can take place either through eating or drinking which is taken in through the mouth into the gastrointestinal tract to aid the process of digestion (Rubilar et al. p 1083).
Digestion is the process by which complex food compounds are broken down into chemical forms which can be absorbed and used by the body. The process takes two phases which are mechanical digestion and chemical digestion (Rubilar et al. p 1083). Mechanical digestion entails the breakdown of large food items by chewing into smaller pieces which can be swallowed. The process of chewing mixes the food with saliva making the process of parasitosis easy. It also mixes the food with salivary amylase which helps the further breakdown of the food.
Chemical breakdown of food follows the mechanical digestion where different enzymes are produced at different points of the digestion track to aid the breakdown of different food components. The food components broken down under chemical digestion are; fats and lipids, proteins and also some minerals.
After the digestion absorption of food follows so that the food can be used for the intended purposes. Under absorption, the digested food gets into the bloodstream and is transferred to different body parts as per their energy requirement and also for storage purposes. Absorption of the food takes place in the small intestine of the gastrointestinal tract. The villi in the small intestine is an important adaptation which boosts the absorption of food items.
Assimilation is the process by which the absorbed food items are transported to the tissues and cells within the organism. The assimilation takes place through the bloodstream of an organism. Assimilation is facilitated by chemical secretion from the liver or other cellular secretion. Assimilation enables the body to have the required nutrients which facilitate the functionality of different body parts. The excess energy is converted into glycogen and stored in the liver. Through the conversion of the excess glucose in the blood, the body can maintain the homeostatic balance.
After the process of digestion, not all food components are broken down and absorbed by the body for use. Due to this these undigested food items need to be excreted from the body to maintain the body in a stable condition (Rubilar et al. p 1083). The excretion enables the body to maintain the process of homeostasis and thus to operate optimally. Egestion takes place through the anus of the organism. Among the excreted waste are the fibres which cannot be digested. In protozoa organisms, the process takes place through exocytosis. Through the process of egestion, the wastes are released which help reduce the pressure on the gastrointestinal tract.
Task 2
Energy in a biscuit
Various approaches have been used to decide the amount of energy in foods for human metabolism by the experts. Calorimeters can determine the aggregate amount of energy in a food. However, not all the ingested food is converted into energy as some part of the food is egested through faeces. Carbohydrates fluctuate in their gross vitality content per gram, how much they are digested and absorbed. From the practical experiment of energy in a biscuit, the total energy increases with the increase in mass of the biscuit. The high amount of energy produced indicated the presence of a large number of calories. For example, the digestive biscuit has 1.0 calories; the shortbread has 1.4 calories while the wetsuits have 0.2 calories.
Carbohydrates are termed as energy giving foods since they are broken down to produce glucose which gives the body with the necessary energy. Different food items have different carbohydrates level; this is because some food items contain monosaccharides while other food items contain carbohydrates in their disaccharide and polysaccharide state. Due to this, therefore, the breakdown leads to the release of the different amount of energy based on the food items ingested as it’s the case with different biscuits.
Below is a table showing the results;
Biscuit-type
Mass of biscuit
(g)
The volume of water (cm³)
Initial Temp
(ºc)
Final Temp
(ºc)
Rise in temp
(ºc)
Total Energy
(j)
Unit Energy
(j/g)
Digestives
4.99
20
20
70
50
4200
841.7
Shortbread
6.50
20
20
90
70
5880
9.1
Wetsuits
1.54
20
20
34
14
1176
763.6
Table 1.1
Task 3 Amount of energy in nutrients
Carbohydrates are the quickest form of energy that the body needs. They may be simple or complex. Simple carbohydrates include glucose and sucrose. They are small molecules to enable efficient breakage and absorption by the body (Wang et al.p3333). They are the fastest form of energy which increases the level of blood sugar at fast rate. Dairy products, fruits, and honey contain enormous amounts of simple carbohydrates.
Protein
The proteins are considered as being bodybuilding foods, due to this. Therefore, the intake of proteins enables the body to grow. Proteins are needed to maintain and repair tissues and also the growth of the body. Protein is not necessary for energy. If the body does not acquire enough calories from other nutrients, a protein is necessary for energy. During starvation, proteins provide the body with the energy required for survival.
Lipids.
Lipids act as energy reserves for the body. The lipids also make an integral part in the structure of some organs. Organisms liver has a lower capability regarding storage. The energy stored in the form of glycogen is lower than the body requirement, and therefore the rest of energy is stored as fats. The energy stored in the form of fats in the body far exceeds the energy stored in the liver. The energy reserves are used during starvation or when the body intake doesn’t meet the body energy requirement (Fujiwara et al. p.1101). According to various researches, fats are said to contain twice as many calories more than proteins and carbohydrates. High fat intake, therefore, may lead to health complication due to increased levels of fat in the blood.
References
Fujiwara, T.K., Iwasawa, K., Kalay, Z., Tsunoyama, T.A., Watanabe, Y., Umemura, Y.M., Murakoshi, H., Suzuki, K.G., Nemoto, Y.L., Morone, N. and Kusumi, A., 2016. Confined diffusion of transmembrane proteins and lipids induced by the same actin meshwork lining the plasma membrane. Molecular biology of the cell, 27(7), pp.1101-1119.
Rubilar, T., Epherra, L., Deias-Spreng, J., Vivar, M.E.D.D., Avaro, M., Lawrence, A.L. and Lawrence, J.M., 2016. Ingestion, absorption and assimilation efficiencies, and production in the sea urchin Arbacia dufresnii fed a formulated feed. Journal of Shellfish Research, 35(4), pp.1083-1093.
Wang, H., Liu, A., Zhao, W., Zhao, H., Gong, L., Chen, E., Cui, N., Ji, X., Wang, S. and Jiang, H., 2018. Metabolomics Research Reveals the Mechanism of Action of Astragalus Polysaccharide in Rats with Digestive System Disorders. Molecules, 23(12), p.3333.