Four Macromolecules Making Living Things
There are four types of organic macromolecules that participate in living organism building: lipids, proteins, nucleic acids, and carbohydrates.
Lipids refer to a group of organic components, fats, oils, sterols and triglycerides. The outstanding property of lipids is their insolubility in water and solubility in organic solvents. Chemically, the lipid is a carbon atom connected with two hydrogen atoms. In particular, hydrocarbon can produce long chains the length of which varies (Wright 38).
Proteins are constituent parts of amino acids. The complicated folds and shapes of proteins determine the formation of their functions. The secondary protein structures appear in the form of chain bends, loops, and twists. The third level of organization endows the molecules with specific functions. Hence, the example of protein is hemoglobin that performs the transportation of oxygen (Starr and McMillan 34).
Nucleic acids belong to the group of complex unions that occurred in living cells consisting of purines, carbohydrates, and phosphoric acid. These macromolecules participate in the formation of DNA and RNA structures that are responsible for cellular and heredity functions (Starr and McMillan 36).
Finally, carbohydrates actively participate in cells formation as they supply them with energy. These molecules consist of carbon, oxygen, and hydrogen in rations of 1:1:2 (Starr and McMillan 28). The simplest example of carbohydrates is sugar, or “saccharide”, which serves as the core energy source for building and functioning of body cells.
Four energy systems Utilized Muscles for Movement Production
In biological terms, energy is an attribute that helps organisms to develop and grow organic cells. It is stored in the substances of the cells like carbohydrates, proteins and lipids, and is released through the interaction with oxygen. This is the first energy system that helps the muscle to produce movement and this is energy process is called metabolism where the main energy source is ATP. Another three systems excluding the usage of oxygen refer to the process of anaerobic glycolysis. This process consists of the participation of carbohydrates in a chain of chemical relations leading to energy release. The third anaerobic energy system is the adenosine-triphosphate-creatine system. The anaerobic activities are those that do not require oxygen and are associated with strength and pressure (Seaward 523). For example, this can refer to weight lifting and different types of fighting. In general, this activity is powerful and fast as it lasts less than a few minutes.
Steps for the Stimulation of Muscle Cells from a Motor Neuron to the Contraction of the Muscle Cells
In order to carry out the muscle contraction, a neuron stimulus is required. Hence, the first stage involves that nerve cells send impulses to a muscle cell by secreting acetylcholine providing access to the communication between a nerve cell and a muscle cell. While producing this chemical substance, acetylcholine diffuses and binds to receptors of the membrane of the muscle cell. The binding generates the electric stimulus that transfers to the inside of the cell. Once the impulse reaches the cell, it helps to release Ca and SR. In its turn, Ca connects to the troponin-tropomyosin complex provoking the exposure of the sites. This series of events contributes to the rise of muscle contraction. The exposure of myosin provokes the release of actin filaments. As the muscle contraction demands energy each myosin is connected with ATP for energy production. At this point, myosin functions as an enzyme thus dividing ATP into ADP, P, and energy. The energy output changes the form of the myosin leading to sliding the actin filaments. This process of myosin bonding and energy release is repeated sharply many times until the muscle shortens in a proper way. Therefore, the contraction is carried out by means of sliding and binding mechanisms and ATP consumption in great amounts.
Works Cited
Crowley, Leonard, V. An introduction to Human Disease: Pathology and Pathophysiology Correlations. US: Jones & Bartlett Learning, 2009.
Saeward, Brian Luke. Managing stress: principles and strategies for death and wellbeing, vol 1. US: Jones and Bartlett Leaning, 2006.
Starr, C., and McMillan, B. Human Biology. US: Cengage Learning, 2008.
Wright, Judene and Princeton Review. Cracking the SAT Biology Subject Test: 2005-2006. Princeton Review, 2005.