Digestion in human beings and other animals is overly dependent on the action of enzymes; in their basic form, enzymes are protein materials that act as catalysts with the ability to produce certain chemical changes. Digestion of food substances usually begin in the mouth. The glands in the mouth produce enzyme salivary amylase (which acts on starch changing it into sugar) and lingual lipase (which kicks off the digestion of lipids) (Chiras 109). The stomach n its part, produces two enzymes, pepsin that breaks down proteins into peptides (Chiras 109). While there are no enzymes produced in the large intestine, small intestine produces enzymes maltase (that breaks down maltose to glucose), sucrase (that breaks down sucrose into glucose and fructose), aminopeptidase (that breakdown peptides into amino acids) and lactase (that breaks down lactose to glucose and galactose) (Chiras 109). The small intestine also provides surface for absorption of digested food substances while the large intestine majorly deals with the absorption of water back into the blood stream.
Chromosome Structure
The structures of the chromosomes have a tendency of changing under the influence of certain factors such as radiations, chemicals, and viruses. Such changes may involve one or more chromosomes. There are several actions that may lead to changes in the chromosome structure. These include; deletions, translocations, duplication, and inversions among others. Deletions involve the loss of some chromosomal material (Cummings 139). And while translocation involves the exchange of chromosomal parts between two or more chromosomes, duplication involves the presence of more copies of chromosomal parts. Inversion, on the other hand, occurs when parts of the chromosome segments are reversed (Cummings 139). In the same manner, in the event that DNA is translated wrongly as result of changes in the nucleotide sequence, the messenger RNA (mRNA) might end up having wrong sequence of bases (three sequences of a base is called a codon) (Petsko and Ringe 6). For instance, if the change occurs in the stop codon, chances are high that a very large protein will be formed.
Sickle cell anemia
Sickle cell anemia is a genetic disorder that occurs when the adult hemoglobin A (HbA) is replaced partially or completely (a translocation) by hemoglobin S (HbS) (Votroubek and Townsend 283). As Votroubek and Townsend assert, the abnormal hemoglobin S (HbS) causes the red blood cells to be hard and sickle shaped; the sickle shaped cells carry less oxygen compared to normal to normal red blood cell. Besides, the abnormal HbS causes parts of the red blood cell to break off thereby blocking the flow of blood. In most cases, the abnormal red blood cells are recognized and destroyed at a faster rate compared to the rate at which red blood cells are produced. In a case where the mother is heterozygous for the trait and the father is homozygous dominant any of their children stand a chance of being sickle cell anemic even though the guarantee is not 100%. This is because, as given in the scenario, the mother is automatically a career (hence has a sickle cell trait) while the father, by virtue that he is homozygous dominant, has sickle cell anemia. This implies that their children have 50% chances of having sickle cell anemia.
Renewable energy and non-renewable energy forms
Fossil fuel exists in three difference types; natural gas, petroleum and coal (Tester, Drake and Driscoll 298). The use of fossil fuels is associated with some of the major environmental effects that have emerged to haunt mankind. Burning fossil fuel leads to production of green house gases such as CO2 and SO2 which are responsible for the causation of global warming. Closely related to fossil fuels, on the grounds that they are yet another source of energy, are renewable sources of energy which, just like fossil fuels, exists in various types inclusive of hydropower, solar energy and wind energy (Miller and Spoolman 304). Renewable energy forms are favored over non-renewable energy forms because, unlike non-renewable energy forms, they are environment friendly and are also inexhaustible.
Works Cited
Chiras, Daniel D. Human Biology. Sudbury, MA: Jones & Bartlett Learning, 2012. Print.
Cummings, Michael R. Human Heredity: Principles & Issues. Belmont, CA: Brooks/Cole, Cengage Learning, 2011. Print.
Miller, G T, and Scott Spoolman. Environmental Science: Problems, Concepts, and Solutions. Belmont, CA: Brooks Cole, 2008. Print.
Petsko, Gregory A, and Dagmar Ringe. Protein Structure and Function. London: New Science Press, 2004. Print.
Tester, Jefferson W, Elisabeth M. Drake, and Michael J. Driscoll. Sustainable Energy: Choosing Among Options. Cambridge, Mass: MIT Press, 2005. Print.
Votroubek, Wendy L, and Julie Townsend. Pediatric Home Care. Gaithersburg, Md: Aspen Publishers, 1997. Print.
