Tuesday, July 2, 2013

Tumor marker : Introduction, Classification and Clinical application


The first tumor marker reported was the Bence-Jones protein (monoclonal light chains of Ig secreted by tumor plasma cells) by precipitation in acidified boiled urine and is the diagnostic marker of multiple myeloma. It was identified by H. Bence-Jones in 1846. The second era (1982-1963) was the discovery of hormones, enzymes, isoenzymes and proteins

Monday, July 1, 2013

How to study Biochemistry ?

Biochemistry is often cited as a challenging, high-volume course that revolves around complex molecular relationships and multi-step reactions.  Successful students must have a strong understanding of the concepts and solid memorization techniques to succeed in this course.  The following study strategies and tips have been formulated from past students that succeeded in their courses to help you learn how to study Biochemistry.

Study Skill #1 - Do NOT procrastinate.  The most obvious, and yet least followed advice by students.  Biochemistry is a high-volume course that progresses and builds its concepts on the fundamentals.  Moreover, many pathways and reactions require memorization and must be acquired over time.

Study Skill #2 - Start with the big picture.  There is no doubt that you will have to memorize multi-step metabolic pathways.  The best way to do this is to start with the big steps and understand the overall flow of the reaction.  First, write only the substrates and products in order.  Do this repeatedly, until it is memorized.  Then add the enzymes.  Then continue to  add co-factors and by-products.  If necessary, label each as an exer- or endergonic reaction and whether or not it is reversible.  Check out Lippincott's Illustrated Reviews: Biochemistry Book for an easy-to-understand approach and large full-color illustrations.  Use the nomenclature to help you remember what is going on in each step. For example, Phosphofructokinase-1, adds a phosphate group (phospho-kinase) to the molecule fructose (-fructo-) at the first position (-1).  By breaking down the pathways and focusing on the terminology it will greatly speed up your ability to memorize them.

Study Skill #3 - Know the terminology and nomenclature, it will make things much easier down the road.  An enzyme or protein will often have its function built into its name.  Take Protein Kinase A for example.  As a member of the Kinases, it will almost always add a phosphate group to its substrate.  Or, take Alcohol Dehydrogenase, structures that are Dehydrogenases always oxidize a substrate.  In this case, it oxidizes alcohols into aldehydes and ketones.  Once you get this down, you will begin to recognize names and automatically correlate them with a specific function.

Study Skill #4 - Buy a dry erase board.  Use this to memorize the pathways and any other reactions you have to know.  There are no short-cuts, but writing things out reinforces them in your memory.  It tends to be much more efficient than staring and reciting from your textbook.

Study Skill #5 - Know the purpose of a reaction. Take the Bohr Effect for example.  An increase in [H+] (decrease in pH), CO2, temperature, and 2,3-BPG all occur in active skeletal muscle. They also all encourage O2 release from hemoglobin.  This makes sense if you think that working muscle is metabolic tissue and needs oxygen to survive.  Incorporating the larger concept will also allow you to predict the flow of reactions in other situations throughout the body. 

Study Skill #6 - Stare at the graphs and plots.  These questions are virtually freebies on exams because all the information you need to solve them is included.  Know what the x- and y-intercept, the slope, and the area under the graph represent.  Know what makes the graphed line move to the right or left.  You will absolutely be asked about the Michaelis-Menten graph and the Hemoglobin dissociation curve - these are staples of biochemistry.

Study Skill #7 - Seek to understand first, and then memorize.  Like many other courses, biochemistry can be overwhelming at first.  There is no easy way to memorize every amino acid or metabolic reaction.  But students always claim that if they take the time to first get the concept down, the memorizing is not as difficult as it once seemed.  Stay focused, break it down into small steps, and practice.

(Source: www.medstudysites.com)
Related Posts Plugin for WordPress, Blogger...