Kamis, 08 September 2011

The Essentials of O Blood Type

Blood can be grouped using various systems. Two of the most well known systems are the Rh system and the ABO system. The ABO blood types were found in the beginning of the 20th century by Karl Landsteiner. He learnt that blood transfusions could sometimes result in the death of the recipient and then discovered the cause. He discovered that certain blood types had antigens and antibodies. For example: A type contains antigen A and antibody anti-B, B type has antigen B and antibody anti-A, AB type has both antigens A and B but no antibody, whereas O blood type contains no antigen but has both antibodies anti-A and anti-B. Antigens coat the surface of red blood cells and quite susceptible to rejection from the antibody. If a donor antigen was rejected by the recipient antibody, it would cause agglutination or destruction of the donor red blood cells in the body of the recipient.

A few O blood type facts are that O does not have ABO antigens therefore will not be rejected by other blood types and that it has all ABO antibodies therefore will always reject blood types aside from O. That is why people with type O blood are called “universal donors”. More fun facts of the O blood type are that mosquitoes in general prefer the O type to others (higher risk of contracting malaria) and that type O individuals are more susceptible to cholera and peptic ulcers. By natural selection, O blood type is probably the most common throughout the whole world.

The less scientific facts of the O blood type concern with personalities of type O individuals. Some consider type O people as energetic and social, as well as flexible in the terms of their viewpoint. Others think that type O people are quitters and often give up midway. Although most people agree that they are honest and respectful toward others and have very strong confidence.

As the most well known blood group classification system, the ABO system gives rise to a kind of fad diet called “The Blood Group Diet”. The base of this diet is the existence of antigens that form different blood types. These antigens allegedly react either positively or negatively toward certain kind of food. Based on this diet, type O people are basically carnivores, A are vegetarians, B are omnivores and AB are mixed diet eaters. For type O individuals, practicing this diet might have some pros and cons. The pros: they can eat meat and fish freely as the diet calls for high protein intake, vegetable haters don’t have to eat vegetable too much. The cons: facts stated that type O individuals are already susceptible to various diseases, so practicing this diet will only add a notch in the disease column because it increases the risk of developing heart disease.

Acne, What You Need To Know

Acne, a non-life-threatening but equally devastating skin disorder, is the factor that can cause a terrible case of low self-esteem in teenagers and young adults. If left untreated or treated incorrectly as to leave scars, it can also lead to depression.

Acne is a type of skin inflammation that is triggered by the plugging of the sebaceous gland. Sebaceous glands produce natural oil to protect our skin from drying. Some people might have slightly more active sebaceous glands than others.

Other factors that can trigger the growth of acne are hormones, diet, weather and unhygienic environment. Some bad habit can cause acne, including not cleansing the skin from makeup and using dirty makeup brushes. The state of a person’s peace of mind might also contribute the growth of acne. Psychological stress, as we all know, causes hormonal imbalance which is partial to androgenic hormones. These hormones increase the activity of the sebaceous glands and therefore, increase oil production. Aside from the above mentioned factors, we also cannot ignore the significance of genetics in the problem of acne.

The location of acne is not always on the face, but also on the chest, the back, the neck, and even the scalp. These areas have an abundance of sebaceous glands and have high oil production. Higher number of sebaceous glands in an area increases the risk of developing acne.

To treat acne, we need to focus on reducing oil production and preventing bacterial infection. One advice that has been the golden rule of handling acne is to never touch the acne with unwashed hands. Better yet, do not touch, period! Forget picking at it. Do not look at the mirror unless you need to apply acne medicine to prevent the urge to pick at the acne. The most important thing to do is to keep the face clean by washing it twice daily, using the correct cleanser (preferably containing salicylic acid). Avoiding excessive use of makeup and stress can reduce the risk of acne significantly, as well as avoiding acne-inducing food.

Kamis, 21 Juli 2011

Dare to Take a Chance in GRE?

Studying abroad had always been a dream of mine since I was a little child. I thought it would be a great experience to live in an entirely different environment with different culture. Not to mention, it would also be really cool to show off to friends and family. To accomplish that, I decided to take a GRE test required for application to this one University in Germany. I have already done my IELTS with adequate result. I would need GRE with the subject of Biochemistry, Cell and Molecular Biology.

So I checked the GRE website and found out that the test would have about one hundred and seventy five MCQs, divided into three sections. There would be problem-solving questions too. And each section would have a question in methodology, possibly statistics. Darn it! I hate statistics.

As I mentioned before, the GRE test is divided into three sections. The first one, BIOCHEMISTRY will take about 36% from the whole test.
1. Chemical and Physical Foundations
* Thermodynamics and kinetics
* Redox states
* Water, pH, acid-base reactions and buffers
* Solutions and equilibria
* Solute-solvent interactions
* Chemical interactions and bonding
* Chemical reaction mechanisms
2. Structural Biology: Structure, Assembly, Organization and Dynamics
* Small molecules
* Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids)
* Supramolecular complexes (e.g., membranes, ribosomes and multienzyme complexes)
3. Catalysis and Binding
* Enzyme reaction mechanisms and kinetics
* Ligand-protein interaction (e.g., hormone receptors, substrates and effectors, transport proteins and antigen-antibody interactions)
4. Major Metabolic Pathways
* Carbon, nitrogen and sulfur assimilation
* Anabolism
* Catabolism
* Synthesis and degradation of macromolecules
5. Bioenergetics (including respiration and photosynthesis)
* Energy transformations at the substrate level
* Electron transport
* Proton and chemical gradients
* Energy coupling (e.g., phosphorylation and transport)
6. Regulation and Integration of Metabolism
* Covalent modification of enzymes
* Allosteric regulation
* Compartmentalization
* Hormones
7. Methods
* Biophysical approaches (e.g., spectroscopy, x-ray, crystallography, mass spectroscopy)
* Isotopes
* Separation techniques (e.g., centrifugation, chromatography and electrophoresis)
* Immunotechniques

The second section is CELL BIOLOGY (28%). The questions would no doubt be about cellular biology and the technology surrounding the imaging of it.
1. Cellular Compartments of Prokaryotes and Eukaryotes: Organization, Dynamics and Functions
* Cellular membrane systems (e.g., structure and transport across membrane)
* Nucleus (e.g., envelope and matrix)
* Mitochondria and chloroplasts (e.g., biogenesis and evolution)
2. Cell Surface and Communication
* Extracellular matrix (including cell walls)
* Cell adhesion and junctions
* Signal transduction
* Receptor function
* Excitable membrane systems
3. Cytoskeleton, Motility and Shape
* Regulation of assembly and disassembly of filament systems
* Motor function, regulation and diversity
4. Protein, Processing, Targeting and Turnover
* Translocation across membranes
* Posttranslational modification
* Intracellular trafficking
* Secretion and endocytosis
* Protein turnover (e.g., proteosomes, lysosomes, damaged protein response)
5. Cell Division, Differentiation and Development
* Cell cycle, mitosis and cytokinesis
* Meiosis and gametogenesis
* Fertilization and early embryonic development (including positional information, homeotic genes, tissue-specific expression, nuclear and cytoplasmic interactions, growth factors and induction, environment, stem cells and polarity)

The third section is MOLECULAR BIOLOGY AND GENETICS (36%)
1. Genetic Foundations
* Mendelian and non-Mendelian inheritance
* Transformation, transduction and conjugation
* Recombination and complementation
* Mutational analysis
* Genetic mapping and linkage analysis
2. Chromatin and Chromosomes
* Karyotypes
* Translocations, inversions, deletions and duplications
* Aneuploidy and polyploidy
* Structure
* Epigenetics
3. Genomics
* Genome structure
* Repeated DNA and gene families
* Gene identification
* Transposable elements
* Bioinformatics
* Proteomics
* Molecular evolution
4. Genome Maintenance
* DNA replication
* DNA damage and repair
* DNA modification
* DNA recombination and gene conversion
5. Gene Expression
* The genetic code
* Transcription/transcriptional profiling
* RNA processing
* Translation
6. Gene Regulation
* Positive and negative control of the operon
* Promoter recognition by RNA polymerases
* Attenuation and antitermination
* Cis-acting regulatory elements
* Trans-acting regulatory factors
* Gene rearrangements and amplifications
* Small non-coding RNA (e.g., siRNA, microRNA)
7. Viruses
* Genome replication and regulation
* Virus-host interactions
8. Methods
* Restriction maps and PCR
* Nucleic acid blotting and hybridization
* DNA cloning in prokaryotes and eukaryotes
* Sequencing and analysis
* Protein-nucleic acid interaction
* Transgenic organisms
* Microarrays

All these informations, I got from http://www.ets.org/gre/subject/about/content/biochemistry.

I would have to prepare the materials for months before I'm ready to take the exam. So If I wanted to take it in February, I would have to start studying ... now?