Luis Fernando Cano                                                                                    September 16, 2010.
PBL 1. Sickle Cells disease. A study case.                                                http://canosblog.blogspot.com/

PBL 1. Sickle cell disease. A study case.

  Lets start with the definition of the sickle-cell anemia. Sickle cell anemia is an inherited blood disorder that affects red blood cells. People with sickle cell anemia develop a serious disease in which the body makes sickle-shaped red blood cells. “Sickle-shaped” means that the red blood cells are shaped like a "C."(http://www.nhlbi.nih.gov/health/dci/Diseases/Sca/SCA_WhatIs.html) . Sometimes these red blood cells become sickle-shaped (crescent shaped) and have difficulty passing through small blood vessels. (www.sicklecelldisease.org). This disease can affect every person in the world but it is more common among African, Caribbean and black origin people. This disease is only transmited from parents to their children and if both parents have this gene the child will have it in a hundred percent of possibilities, but if only one parent has it, the possibilities of having the disease decreases to a fifty percent.

  An objective of biology covered by this disease is the study of the genetic bases for inheritance in organisms as we learned in the introduction to the subject. Biology helps us to understand the genes that are transferred from parents to children and so on. We have to mention that not only biology is the science that helps understanding the disease, the other sciences that are involved are: chemistry, which studies the molecules and cells that change with the disease like the blood; physics, with physics we can understand how blood moves in the body and what path does it follow; mathematics, with mathematics we can measure the levels of blood and hemoglobin; geography, we can use some geographical data to measure where the disease comes from or where it is more concentrated; computer science can be used to research and to use some software that can show us the DNA structure and where is the problem, we can also use it to make some tests without hurting or damaging a living being; ethics are important beacause life is involved in the treatment of the disease, gene manipulation is also a part of the cure so scientists need to be careful with that information and with the preservation of life. There are also some branches of biology used for treating this disease as biochemistry, biophysics, gentics which is very important for this disease, cytology which studies the cells, anatomy also can be used, embriology can be used to determine the dna of the reproductive cells and microbiology may be needed because of the microorganisms involved with the disease. We can say that an 80 % of sciences and biology branches are needed for the research and treatment of the disease.

  The levels of organization show us that first of all the molecules are affected because the DNA comes wrong codified, after that the cells are disturbed by the disease, the next level of organization affected is the tissue because the blood is a bad quality blood, after that the organs begin to present difficulties because of the bad tissues, after that the system is affected because the organs present difficulties doing their main functions, then it affects the whole organism, and finally the organism may directly affect to the population by inheriting the bad gene to his children.


 The macromolecules affected by the disease are the proteins and the carbohydrates which are are the hemoglobin and the deoxyribose in the DNA respectively. Hemoglobin is a transport mechanism of oxygen and carbon dioxide in the red blood cells. The hemoglobin takes a different shape when the “deoxygenation” occurs but because of the disease the hemoglobin does not return to its regular shape making it a solid structure. (http://evolution.berkeley.edu) The deoxyribose of the DNA presents the mutation responsible of the sickle cell anemia.


  The levels of structure that the hemoglobin are primary which are the amino acids joined; secondary that contains the alfa helix and the pleat; tertiary has two main structures: globular and fiber and finally the fourth level which is a tridimensional shape presented by the union of two or more polypeptide chains (Biggs, 2009;Velazquez, 2009). The level affected by the mutation is the primary level because it affects the sequence of aminoacids and a letter of the DNA changed by the anemia. This change involves the creation of the sickle cell anemia in the cell, wich continues until it affects the whole population.

  For this disease there are some preventing methods such as the gene manipulation or the tests for knowing if you have the Trait such as a simple blood test. I think that ethics are essential because when you talk about gene manipulation you talk about creating or destroying life because the babies that are manipulated are alive and they have rights to live not only because they are sickle cell carriers they are going to be less than us. I think that the blood test is better for nowing if you have the gene and after the results you will know and you will have to be responsible for having or not children that may carry the gene.

  In conclusion, the sickle cell anemia is a disease that is inherited and everybody can have it but it is more common in Caribbean, African and black origin people. The disease goes thorugh different levels of organization, from the molecule to the population. We need all kinds of science and biology branches to fight against the disease, we need to study it and then apply the different knowledge to defeat it. The proteins and the carbohydrates  are the macromolecules that are involved in this disease, because of the mutation of the hemoglobin and the deoxyribose all of this happens. Finally, the preventing methods that we have today are important for the fight against the sickle cell anemia, but they also need to be practiced in an ethical way without playing with life and respecting the decisions of each human being.

REFERENCES

http://www.sicklecelldisease.org/about_scd/index.phtml
http://en.wikipedia.org/wiki/Protein_structure
http://evolution.berkeley.edu/evosite/evo101/IIIC2aCasestudy.shtml
 http://www.nhlbi.nih.gov/health/dci/Diseases/Sca/SCA_WhatIs.html

Rules for the mission

Rules for the mission

1. Be respectful to the crew.
2. Listen to the crew's opinion.
3. No food in the ship.
4. Possitive attitude on the mission.
5. Be tolerant with the alien's opinions.
6. Be unique.
7. Participate in all the activities.
8. Be responsable with your actions.
9. Do all the tasks.
10. Exceed expectations.

First entry in the blog, hi everyone!