Wednesday, April 25, 2012

Three Major Themes

Three major themes from the course are structure, function, and enzymes.
This course covered the structure of many different molecules.  We learned differences in structures of the amino acids, peptides, proteins, lipids, nucleic acids, etc.  Proteins alone have up to four different types of structural components. There can be different forms of molecules, molecules that have the same composition but are arranged differently.  For example left-handed amino acids are the active form found in eukaryotes.  If a right handed amino acid was found it would not be able to play its role.  We learned the difference types of bonds, such as polar bonds, covalent bonds, peptide bonds, hydrogen bonds.  The way things are bonded impacts what they do, or what they are capable of doing.
Function of the molecules and how they work as a team to keep organism alive.  Certain molecules may attract other molecules needed.  Other molecules proofread and repair damaged cells.  For example in Replication there are five different types of polymerase each with their own specific function.  For example in prokaryotes, polymerase I is involved in synthesis, proofreading, repair, and removal of RNA primers.  While pol III is the main polymerizing enzyme.  Each molecule found in organisms has a specific purpose.
Enzymes are important in aiding life processes that occur.  They help to speed up the reaction and can be inhibited or activated, depending on what surroundings are present.  For example phosphofructokinase, an enzyme in glycolysis is activated by AMP while it is inhibited by ATP.  There are different classes of enzymes such as kinases or isomerases.  Each class of enzyme aids a different type of reaction.  For example kinase reactions aid phosphorylations. 
These themes are connected because structure determines function, and enzymes aid in function.  A change in structure changes the task of the molecule.  Without the presence of a needed enzyme, a reaction may not occur, and the molecule will not perform its purpose.  All three themes are important in biochemistry, and were learned in other science courses.  This course has provided me with the knowledge to make these connections between the themes.  Biochemistry had brought all these themes together to give a better presentation of the overall picture.

Thursday, April 19, 2012

Glucose, Energy Production, and Your Body In a Nutshell

Glucose is a carbohydrate that enters your body from the food you eat.  It can be stored in the muscle tissue as glycogen.  Glucose is used to produce energy by going through the glycolysis cycle.  Glycolysis is an anaerobic process, a process that does not require oxygen.  This allows for a faster production of energy than a aerobic process, a process that requires oxygen.  Think of a sprinter, a sprinter needs a smaller amount of energy fast compared to a long distance runner who needs more energy over a longer period of time.
The process of glycolysis  is a complicated ten step reaction that may contain foreign words for those who have not taken advanced chemistry courses.  Each reaction has its own enzyme, which helps to aid the reaction.  Glycolysis starts with glucose and ends with four molecules.  There are two molecules of pyruvate and two molecules of ATP (energy). Pyruvate will then continue on to other processes and generate 32 molecules of ATP.  Pyruvate can also synthesize glucose, through a process called gluconeogenesis.  Gluconeogensis is almost the exact reversal of glycolysis, however there are 3 irreversible reactions of glycolysis.  These reactions are different in gluconeogenesis and may require a different enzyme.