Biology: Biochemistry

Jordan Wong
Schiefer
Acc Bio Block 6
11/15/12

Unit 4 Biochemistry relates to all things living because biochemistry makes up everything living. The atoms that make up the cells within our body are a part of biochemistry. There is carbon in every living thing and carbon based molecules are a part of biochemistry. Unit 4 describes the biochemistry in all living things. It explains the atomic structure and ions, properties of water and pH, organic molecules, chemical reactions and enzymes. With atomic structure there are three subatomic particles that form together to create an atom of an element; protons, neutrons, and electrons. Protons are positively charged and form the nucleus of an atom with neutrons that carry no charge. Electrons are negatively charged and are constantly moving around the nucleus. Ions are created when electrons move from one atom to another atom changing the charge of that atom to either positive or negative. When electrons move they form bonds. There are two types of bonds; ionic and covalent. Ionic bonds are formed through electrical forces while covalent bonds are a lot stronger and are formed when atoms are forced to share electrons. Water has different properties. One is cohesion which is the attraction between molecules of a given substance. Cohesion in water molecules causes surface tension which makes the water molecules stick together. Another is adhesion which is the attraction of molecules in different substances. There are two sides to a pH scale, base and acid. Acids are a compound of substances that release hydrogen ions in a solution. Acids taste sour, are corrosive to metal, and it turns litmus paper red. Bases on the other hand are compounds that removes hydrogen ions in a solution. Bases taste bitter, makes good cleaning supplies(soap, detergent, bleach, Windex) and turns litmus paper blue. A pH scale gives a numerical value to the acidity of a solution ranging from 1-14 with the lowest being highly acidic to the highest being highly basic while the middle (5-9) is neutral. Carbon based molecules have very unique bonding properties and are the basis for almost every molecules in living things. Carbon based molecules can bond in 3 ways. They can bond in straight chains, rings, or in branched chains. These molecules bond together to create monomers which in turn bond together to create polymers. There are four main types of carbon based molecules in living things. Carbohydrates are used for energy. Carbs are sugars and starches composed of carbon hydrogen and oxygen, which are then broken down into usable chemical energy. Lipids create barriers. They are non-polar molecules that include fats oils and cholesterol. Many lipids are in triglyceride form which stores the fat for later uses but if not used soon then will just sit on your body as fat. Proteins are the building blocks of living things. Proteins are polymers made of monomers called amino acids. Proteins do many functions from creating new cells to repairing the skin over the knee you scraped on the floor. Nucleic acids are the blueprints, the ones that tell everything what to do, where to go, and what to build. There are two types of nucleic acids, DNA and RNA. Chemical reactions change substances into different substances by breaking and forming chemical bonds. Reactants are the substances that are being changed while products are the substances that are being formed. Bond energy is the amount of energy needed to break the bond between atoms. Activation energy is the amount of energy needed to start a chemical reaction. An exothermic reaction is when more energy is released during the chemical reaction than is used to start the chemical reaction. Endothermic is when less energy is released during the chemical reaction than is used to start it. Enzymes break down substrates. Enzymes and substrates can fit together like a lock and key. Enzymes help to break down amino acids and starches into simple sugars. Catalysts are substrates that decrease the amount of activation energy needed for a chemical reaction. The atomic structure, ions, properties of water, pH, organic molecules, chemical reactions and enzymes are all a part of biochemistry. Biochemistry makes up all living things. Carbon based molecules can bond together in 3 different ways. Cohesion is when molecules of a same substance stick together while adhesion is when different substances stick together. Acids are low numbers while bases are high on the pH scale. There are carbon based molecules in all living things. Exothermic releases heat, endothermic absorbs heat. Enzymes help to break down substances for later use.