Unit 2 Reflection

      This unit was about the chemistry of life.The first section was about atoms. It talked about protons, neutrons, and electrons.Subatomic particles that make up atoms are protons, neutrons, and electrons. A chemical element is a pure substance that consist entirely of one type of atom. Atoms of the same element that differ in the number of neutrons are isotopes. Because they have the same number of electrons, all isotopes of an element have the same chemical properties. A chemical compound is a substance formed by the chemical combination of two or more elements in definite proportions. An ionic bond is formed when one or more electrons are transferred from one atom to another. A covalent bond forms when electrons are shared between atoms. The molecule is the smallest unit of most compounds.Van der Waals forces are when molecules are close together and a slight attraction develops between the oppositely charged regions of nearby molecules.
      The second section was about the properties of water. It also talked about valence electrons and why carbon was so versatile. Carbon is very versatile because it was four valence electrons. It can bond with different elements easily. Water is polar because there is an uneven distribution of electrons between the oxygen and hydrogen atoms. Cohesion is an attraction between molecules of the same substance. Adhesion is an attraction between molecules of different substances. A mixture is a material composed of two or more elements of compounds that are physically mixed together but not chemically combines. All components of a solution are evenly distributed throughout the solution. A solute is the substance that is dissolved. A solvent is the substance in which the solute dissolves. The mixture of water and non dissolved material is called suspension. Buffers are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH.
      It also talked about carbohydrates, lipids, proteins, and Nucleic acids. Proteins are made up of amino acids. It also talked about what an acid and base were. The topics about proteins was the most confusing. I feel like I pretty much understand everything about atoms, but not macromolecules. Different enzymes work better in different conditions of pH and temperature.Smaller units called monomers, join together to form polymers. Carbohydrates are compounds made up of carbon, hydrogen, and oxygen atoms, usually a ratio of 1:2:1. Living things use carbohydrates as their main source of energy. Plants and some animals also use carbohydrates for structural purposes. Lipids are made mostly of carbon and hydrogen atoms. Lipids can be used to store energy Some lipids are important parts of biological membranes and waterproof coverings.