2 Chapter 2 The Chemical Level of Organization
By Aylin Marz
Motivation. Every day nurses are subjected to chemicals including those found in disinfecting solutions, medications with toxic effects, various gases including those used in anesthesia, radiation producing chemicals used in treatment, as well as chemicals found in bodily fluids such as blood, saliva and urine. Generally, the doses or concentrations of these chemicals are too low to cause harm but with repeated exposures there is always additional risk of toxicity. Being aware of the benefit and harm of the chemicals nurses are exposed to can help reduce risk of developing diseases from these exposures.
The concentration of a chemical, as well as its chemical reactivity with the biomolecules within our bodies, plays a role in how it affects health. Therefore, understanding chemical reactions can help nurses avoid harm to self and patient. Different chemical characteristics allow for mixing, dissolving, or reactivity to occur between compatible chemicals. This concept is also important in nutrition and in understanding what type of biomolecules are needed for energy, healthy growth and development. Nurses informed about chemistry can help avoid harm and decide how to advocate healthy eating habits in their patients and communities.
Learning Objectives
Upon completion of the work in this chapter, students should be able to:
- Apply concepts related to atoms and elements to solve problems on isotopes
- Distinguish chemical reaction types such as hydrolysis degradation resulting in protein breakdown
- Perform an enzymatic reaction determining the reactants and products
- Apply the scientific method to determine the effect of factors affecting enzymatic activity
Background.
Life is made of chemicals which in turn are composed of various atoms composed of neutrons, protons, and electrons. There are many elements composed of atoms with different chemical properties each. Each element is determined by the number of its protons and this is called its atomic number. For example, Carbon is an element indicated with a C in the periodic table, and has an atomic number of 6. The number of protons and neutrons of an atom make up its atomic mass. There are multiple versions of an element based on its mass. For example, Carbon-12 has a mass number of 12 since it has 6 protons and 6 neutrons. Carbon-14 has a mass number of 14 since it has 8 neutrons. The different versions of an element are called its isotopes (Figure 2.2).
The electrons that orbit around the proton+neutron nucleus of an atom are negatively charged and are responsible for the interactions between different atoms. The negative charge of an electron is counteracted by the positive charge of the protons in what we call a neutral atom. For example, a neutral Carbon atom has 6 positively charged protons in its nucleus and 6 negatively charged electrons that orbit around the nucleus. The electrons of an atom are placed in orbitals (Figure 2.3)