Biology

Biology Essay

Life exists as a complex network or web of interrelationships. The operation of cells, organisms, species, communities, and ecosystems depends on multitudes of connections between the components of various biological systems. Complex organisms such as humans are internally not a simple design. There are many intricate systems working together and tedious processes that occur inside cells in order for daily functions to be carried out. Biological systems are a lot like a car, certain things need to be present and work in order for everything to function correctly. At the microscopic level, there are special compounds called macromolecules that are connected and involved in almost all bodily systems in order for function to occur, they are like the battery of a car. In fact, it could be said that macromolecules are the most important organic compounds in the body. Everything is so interconnected it is difficult to say what macromolecule is more important than the other, because if any were missing many systems wouldn't be able to function and the organism would die. For example, if something as small as one nucleotide was removed from a DNA sequence, that could completely change a person's quality of life. Then again, if there where many insulin proteins that were denatured for some reason, the persons blood sugar level could become excessively high making this problem potentially life threatening. Macromolecules might play a huge role, but there are other important factors that are connected in the equation to sustain life, such as water's polarity and its ability to create H-bonds. All of these molecules are small but all are connected in the bigger picture. Their responsibilities are parallel to those of fuel or a battery within a vehicle, without them no other parts or systems would function properly.

Water is many molecules that consist of two parts hydrogen and one part oxygen. Water's structure is very important to many systems in order for the body to function. The oxygen molecule has a greater electronegativity than the hydrogen molecules so the electrons are pulled more towards the oxygen molecule creating partial charges. This is what makes water polar, which then is the reason why H-bonds are created. H-bonds are a very strong bonds that take a lot of energy to break. The structure of water creates many unique properties such as high specific heat capacity. This means that hydrogen bonding causes liquid water to absorb a large amount of heat. High specific heat capacity is important for our bodies to keep a constant internal temperature. In addition, water's high specific heat capacity helps our earth regulate a constant temperature. Another unique property of water is cohesion and adhesion; this is the ability of water molecules to stick together. This property can be important for the circulatory system of the body. Blood is mainly made up of water; cohesion and adhesion ensure that there will be a constant flow through the veins and arteries, so that oxygen and nutrients can be transported to the proper destination. The plasma membrane is non-polar, but water is able to diffuse through because it is a small enough molecule, this is vital because the cell needs water to survive. Water's polarity becomes important in photosynthesis. Water is needed to diffuse into the granum where the Z protein splits it into H+ and oxygen which is necessary to create a concentration gradient, so essentially ATP can be produced. The Z protein then uses the electrons from the H+ ions to replace the missing ones in chlloraphyl p680. H-bonds hold the nucleotides together in the DNA, so the DNA does not zip up. H-bonds are also involved in holding proteins together.

Proteins play such an important role in a great number of biological processes. First of all taking into account a cell's structure, the cell's membrane is embedded with transporter proteins. These proteins have a role in transporting larger molecules in and out of the cell, known as facilitated diffusion. Enzymes are proteins that catalyze reactions in cells; they lower the activation energy so that reactions can proceed at a rate that can sustain life. Enzymes have specific tasks and help out in many cellular activities such as cellular respiration. For example, in pyruvate oxidation there are transport proteins in the mitochondria membrane to allow the pyruvate molecules to pass through into the mitochondria. Enzymes also help to catalyze the Krebs cycle. The pancreas contains beta cells known as insulin, where insulin is a protein. The specific task of this protein is to lower the blood sugar level. If the insulin protein becomes mutated, therefore doesn't function properly, this is what leads to diabetes. Diabetes can be life threatening if not treated properly, this is just one example that shows how important proteins really are. Your body, in fact, can not even carry through a monotonous task such as lifting your arm without the aid of proteins present. The electric signal to move your arm can not make it through without receptor sites, which are proteins. These receptor sites are embedded in the postsynaptic membrane, which acetylcholine binds to. This causes the Na+ gates to open and becomes depolarized. The signal will keep traveling the afferent nerve, then down the efferent nerve and then to the effector organ where your muscle will contract. Proteins even prevent you from getting an infection or disease. Antibodies are made up of four protein chains. The antibodies attack pathogens from invading your body, eventually killing off the infection. An example to show how important antibodies are for our immune system is aids. To test for aids, they take a count of your antibodies in your blood. If you do not have enough antibodies, you will not be able to fight infections. This is really life threatening, and it is not unusual if death occurs from this disease. In fact, this disease has caused a decrease in populations, especially in Africa. This disease is an epidemic in Africa and is caused by something as simple as a lack of antibodies.

Nucleic acids are made up of nitrogenous bases, five carbon sugars, and phosphate groups. There are nucleotides that will form base pairs with each other, and wind up in a "spiral staircase," known as a helical shape. The order of the nucleotides matter depending on what kind of information is required to perform a specific task. It could be as simple as one nucleotide missing, and that would create a mutation where the wrong kind of information is sent to create the wrong amino acid sequence. There are different types of mutations such as deletion, insertion, silent, missense, nonsense, and frame shift. Some of these mutations are beneficial such as a silent mutation. A harmful mutation would be nonsense. This occurs when a change