Cell membrane and Function

Topics: Atom, Protein, Chemical bond Pages: 8 (2864 words) Published: October 21, 2013
Review 1: The Chemistry and Molecules of Life
Please note that this is a general outline of some of the topics we will have discussed and are detailed in chapters 2-5 of your textbook. While this gives you an idea of some of the terms/phrases you are responsible for, not all the material we covered is included. You are responsible for everything discussed in class, but NOT for material in the book that was not addressed in lecture. Please do NOT assume that if you know the concepts/answers to the terms below, you are prepared for an exam. You need to spend time with your lecture notes, and prepare your own review questions in addition to the ones provided here. WHITE 301

General Themes and Topics

Atoms, Elements and Molecules (Chapter 2)
Describe the general structure of an atom and define atomic number, atomic mass, valence electrons, and isotopes. Atomic number – the # of protons in the nucleus
Atomic mass – the number of protons and neutrons
Valence electrons – the number of electrons in the outermost shell Isotopes – elements that have the same atomic number but different atomic mass Distinguish between elements and compounds; name the most abundant elements in the human body if water is included; name some that are crucial but less abundant An element is a pure substance that can’t be broken up

A compound consists of two or more different elements
Carbon, Hydrogen, Oxygen, and Nitrogen are the most abundant elements Iron and Iodine are crucial but less abundant
Distinguish between ionic bonds, covalent bonds (how are nonpolar and polar covalent bonds different), and hydrogen bonds, noting their relative strengths and in what types of molecules they might be found. Give an example of each in a biological system. Covalent bonds are bonds that involve the sharing of a pair of valence electrons by two atoms. This type of bond is usually only between two nonmetal elements. Covalent bonds are strong bonds compared to other bonds, except ionic bonds. Also molecules formed through covalent bonds have low melting points and low boiling points as well. Nonmetal to nonmetal bonds are known as covalent bonds such as O2, H2, or even CH4. Phosphoanhydride bonds of ATP, which are covalent bonds, are considered to be chemical potential energy capable of being used in biological reactions. Also covalent bonds are the major bonds involved with all organic molecules. Ionic bonds are bonds that involve the attractions between two oppositely charged atoms, an anion and a cation. The transfer of electrons between these two ions allows this bond to form but the true bond between these two ions is caused by the definition of ionic bonds stated above. Ionic bonds are the strongest bonds out of all three. Ionic compounds formed through ionic bonds tend to have a higher melting point and a higher boiling point as well. Ionic bonds are also the bonds between a metal and a nonmetal element. They are usually found in salts such as iodized salt or table salt, NaCl. Many ionic bonds are found in biological systems as salt bridges within proteins. Hydrogen bonds are formed when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom. Water is the best example for hydrogen bonding and it is also found within other important places such as DNA. This type of bond is considered to be a weak chemical bond but it has strengths in numbers. The bond is most commonly found within H2O but it can also exist within other molecules such as NH3 for example. A biological system within which these bonds are found is the DNA, because the bonds between the alternating nitrogenous basis are basically hydrogen bonds. Polar covalent bonds have a greater difference in electronegativity Define a chemical reaction, and distinguish between reactants and products. The making and breaking of chemical bonds, leading to changes in the composition of matter are chemical reactions. Reactants are the starting...
Continue Reading

Please join StudyMode to read the full document

You May Also Find These Documents Helpful

  • Essay on structure and function of plasma membrane in cells
  • Cell Membrane Essay
  • The Cell Membrane Essay
  • Cell Membrane Essay
  • Structure and Function of the Cell Membrane Essay
  • Essay on Cell Structure and Function
  • Essay on Metabolism Cell Membrane and Protein Synthesis
  • Essay on Major Structural Components of the Cell Membrane

Become a StudyMode Member

Sign Up - It's Free