Chapter Two Reading Journal

Questions:

Why is Chemistry important to Biology?
- Chemical reactions within the systems of organism are often essential to the basic functions of life. Carbon, Oxygen, Hydrogen, and Nitrogen account for 96% of living matter. Medically speaking chemistry helps doctor study the more intricate functions of metabolism with the use of radioactive isotopes. Understanding chemical reactions gives us a better understanding of organisms internal functions as well as the effect they have on external things (i.e. other organisms or other surroundings)

What’s the difference between a Polar and Non-Polar Bond?
- A polar bond is a covalent bond in which the electrons are pulled towards the nucleus of one atom more strongly than the other. In a non-polar bond the electro negativity of atoms is equal meaning that the electrons are completely evenly shared.

What is a Hydrogen Bond?
- This is a bond made when Hydrogen is already involved in a polar bond and the molecule formed from that bond is then attracted to another atom that is electronegative. These bonds often occur within the cells with Oxygen or Nitrogen atoms being the other involved elements.

Facts:
- The mass number is the sum of protons and neutrons
- The farther an electron is from the nucleus the more potential energy it has
- The chemical behavior of an atom depends mostly on the number of electrons in the outermost shell
- An atom’s valence is typically equal to the number of unpaired electrons needed to fill the atom’s outer valence
- The strongest chemical bonds are ionic and chemical, but the weakest chemical bonds are equally important in the function of a cell





The diagram above displays how important the shape of molecules is. Molecules within organisms only attach to molecules if they have the right structure. The portion of endorphin molecules that attach to the brain cell is very similar to a portion of the morphine molecule. These similarities in structure allow morphine molecules to attach the brain and have similar effects on the brain to that of an endorphin. This makes morphine very useful in prescribing for people that aren’t producing enough endorphins in times of stress.

Summary:
All matter is made up of elements and combinations of elements called compounds. Carbon, Hydrogen, Oxygen and Nitrogen are amongst the key elements within living things. Trace elements are also essential to living things but need in smaller amounts than the above-mentioned elements. Atoms are the smallest unit of matter that can still be considered an element; atoms consist of neutrons protons and electrons. Isotopes are formed when an element has more neutrons than protons. Electrons are the key to chemical bonding. Covalent bonding is determined by the number of electrons in an atom’s valence shell. Ionic bonds occur when negatively and positively charged atoms are pulled together. There are a number of weaker bonds that occur and also have a large impact on cells and organisms as a whole. The creation and the decomposition of chemical bonds make up the chemical reactions that keep living things functioning.