+1-817-968-5551
+61-488-839-671
+44-7480-542904About Expert
Requirement
Role and absorption of nutrients
Task1: Use RDA tables to explain why the dietary energy requirements of young children, adolescents, elderly people and pregnant and lactating women can vary. Giving examples of different nutrients, explain why the dietary requirements may vary for people of different ages, gender and occupations.
The following are the comparisons and contrasts for showing such variations for the recommended dietary requirements in young children, adolescents, elderly people and pregnant and lactating women
-
As the young children grow, the BMR is generally the largest component of the requirement. Because of differences in the timing of the pubertal growth spurt, both weights and heights at any given age are rather variable.
-
Adolescence is a time of rapid physical growth and involves in physical activity therefore, they are in need of more nutritional requirements to support growth and development. The additional energy and nutrient demands of pregnancy place adolescents at nutritional risk.
-
Aging is associated with various metabolic and physiologic changes that may contribute to alter dietary energy requirements for older adults. These changes may include progressive changes in body composition (especially the loss of muscle mass due to sarcopenia), declines in physical activity, physical functional capacity and total food intake and increased frequency of disease (Campbell et al., 2008)
-
Sufficient energy is a primary dietary requirement of pregnancy. If energy needs are not met, available protein, vitamins and minerals cannot be used effectively for various metabolic functions (Meinila et al., 2015). Energy requirements are greater for pregnant adolescents than for their non-pregnant peers. Current recommendations suggest pregnant women should increase their average energy intake by 300 calories per day during the second and third trimesters of pregnancy. In addition, monounsaturated and polyunsaturated fatty acids should be the predominant types of fat consumed during pregnancy. Sources of these fats include olive, canola, safflower and sunflower oils, tub margarine, peanuts, peanut butter, walnuts, and fish. The need for iron increases as pregnancy progresses. Iron needs increase throughout the second trimester reaching a peak requirement in the third trimester when fetal demands are greatest.
You can get the best biology assignment help at Allassignmenthelp.com because we cover a wide range of subjects in this field. If you believe you are stuck with a marine biology assignment help, we are here to assist you. We cover all of the major branches of science in our cheap assignment writing service, including physics, chemistry, and biology.
Table-1: Showing RDA for individuals with varying age and condition (RDA, n.d)
-
The requirement of nutrients for lactating women is 1300 mg calcium per day for those age 18 or younger, and 1000 mg calcium for those older than 18.
-
Vitamins supplementation is also relatively high for young children and pregnant woman in comparison to other individuals.
-
Due to associated developments and biochemical variations in the individual, the energy requirements differ from person with respect to age and condition. To meet the demands of individual, the recommended diet allowance differ.
Task-2: Explain what happens to meat sandwich as it passes through the digestive system. In your answer, you must include reference to mechanical and chemical digestion, ingestion, digestion, absorption, assimilation, digestion and the structure and function of the alimentary canal. When explaining absorption, make sure that you explain the structure and function of Villi in this process. Ensure that you include the location and roles of the key digestive enzymes.
The sandwich consists of bread, mayonnaise, meat and salad as deep fried or roasted form. As the sandwich composes of proteins, fats and carbohydrates in solid form, undergo mechanical digestion via movement within the mouth by mastication (chewing) into smaller pieces. Once the stuff enters the stomach, under go for peristaltic moments followed by chemical digestion. Digestive enzymes and water are responsible for the breakdown of complex molecules (fats, proteins, and carbohydrates) into smaller molecules and facilitate their absorption. The major enzymes involve in the digestion of sandwich include pepsin from the parietal cells of stomach that covert the proteins in to polypeptides and smaller peptides. Lipases, a group of lipolytic enzymes from pancreases (secreted in to intestine) that cleave fats into simple fatty acids (Pandol, 2010). Amylases, a group of enzymes that catalyze the hydrolysis of starch to sugar to produce carbohydrate derivatives. Trypsin, a proteolytic digestive enzyme produced by the exocrine pancreas that catalyzes in the small intestine the breakdown of dietary proteins to peptones, peptides, and amino acids. Chymotrypsin, proteolytic enzyme produced by the pancreas that catalyzes the hydrolysis of casein and gelatin. The digestive system is also associated with many accessory organs responsible for producing an array of chemical enzymes: salivary glands, pancreas, liver, gall bladder.
The components obtained after the cleavage of sandwich are absorbed most from small intestine. The small intestine consists of three segments including duodenum (port of entry for pancreatic duct and common bile duct), jejunum (thick) and ileum (associated with numerous Peyer's patches). The entire luminal surface of the small intestine has villi, small projections of mucosa (Shaw et al., 2012). The villi are lined with simple columnar epithelial cells, also called enterocytes. The cells are tall with middle to basal nuclei and have an apical brush border, also known as microvillus. Both villa and microvillus function to increase the surface area for greater absorption. The absorption of the resultants i.e., nutrients from the sandwich will be absorbed from the microvillus and villa. While traversing the stuff as chyme, water, sodium, chloride, potassium, entities of proteins (aminoacids), carbohydrates(glucose) and fats (fatty acids); vitamins, minerals, antioxidants, and phytochemicals will be absorbed from intestine
Fig-1: Structure of an intestinal villus (Villus, n.d)
Task-3: Explain the characteristics of enzymes and (using named examples), the lock and key theory of enzyme action. Include in your answer, an explanation of the role of enzymes in both catabolic and anabolic reactions.
The substrate binds to a small section of the enzyme referred to as the active site (Fig-2) to produce a product. The induced-fit model is actually an offshoot of an earlier theory proposed by Emil Fischer (Branlant et al., 1983), the lock and key model. The lock and key model states that the substrate acts as a 'key' to the 'lock' of the active site. The active site and substrate are exact matches for each other, similar to puzzle pieces fitting together. In this model, only a single substrate is the precise match for the enzyme. Once the enzyme finds its exact counterpart, the chemical reaction can begin. The induced-fit model is generally considered the more correct version. This theory maintains that the active site and the substrate are, initially, not perfect matches for each other.
Fig-2: The substrate binds with the active site of the enzyme to start the reaction. (A) Flow of events and (B) Enlarged view
The following are the examples for such action
Examples for catabolism
-
Enzymatic digestion of proteins by the enzyme, trypsin into polypeptides
-
Enzymatic digestion of fats by the enzyme, lipase into simple fatty acids
Examples of anabolism are protein synthesis, glycogen synthesis, lipid synthesis RNA synthesis and DNA synthesis.
-
Glycogen synthesis is a polymerization reaction where glucose units in the form of UDP-glucose. These are added one at a time to a growing polysaccharide chain. The reaction is catalyzed by glycogen synthase.
-
Protein anabolism is essential to reduce fat and increase the muscular strength.
Place Order For A Top Grade Assignment Now
We have some amazing discount offers running for the students
Place Your OrderReferences
-
Branlant, G., Eiler, B., Biellmann, JF., Lutz, HP & Luisi, PL (1983) Applicability of the induced-fit model to glyceraldehyde-3-phosphate dehydrogenase from sturgeon muscle. Study of the binding of oxidized nicotinamide adenine dinucleotide and nicotinamide 8-bromoadenine dinucleotide. Biochemistry. 22(19) 4437-43.
-
Campbell, WW., Johnson, CA., McCabe, GP & Carnell, NS (2008) Dietary protein requirements of younger and older adults. Am J Clin Nutr. 88(5)1322-9.
-
Meinila, J., Koivusalo, SB., Valkama, A., Rono, K., Erkkola, M., Kautiainen, H., Stach-Lempinen, B & Eriksson, JG (2015). Nutrient intake of pregnant women at high risk of gestational diabetes. Food & Nutrition Research, 59, 10.3402/fnr.v59.26676. http://doi.org/10.3402/fnr.v59.26676
-
Pandol SJ (2010) The exocrine pancreas. San Rafael: Morgan & Claypool life sciences. Digestive enzymes. Available from: http://www.ncbi.nlm.nih.gov/books/NBK54127/
-
RDA (n.d) Retrieved from http://www.time-to-run.com/nutrition/rda.htm
-
Shaw, D., Gohil, K., & Basson, M. D. (2012). Intestinal mucosal atrophy and adaptation. World Journal of Gastroenterology?: WJG, 18(44), 6357–6375. http://doi.org/10.3748/wjg.v18.i44.6357
-
Villus (n.d) Retrieved from http://www.daviddarling.info/encyclopedia/V/villus.html
Give your grades a boost
Just share your requirements and get customized solutions on time.
-
1,168,768 Orders
-
4.9/5 Overall Rating
-
5,052 Experts
