Biochemistry

General Topics Part 1: Properties of Water Part 2: Key Organic Compounds Part 3: Characteristics of Enzymes

Water Hydrogen Bond: a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other. Covalent Bond:A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atom

Key Properties of Water Cohesion The ability of water molecules to stick to each other Adhesion The ability of water molecules to stick to other things Capillary Action The ability of water to move up a tube High Specific Heat The ability of water to resist temperature changes Universal Solvent The ability of water to dissolve many substances

Why does water have these properties? Water is a polar molecule which means each molecule has an unequal charge. There is a slight positive end and a slight negative end. Due to the polarity water forms hydrogen bonds between molecules Polarity is the driving force behind all of its other properties

The pH scale pH is a measure of how many hydrogen ions are in an aqueous (liquid) solution A basic solution has a value between 7.1-14 An acidic solution has a value between 6.9-0 A pH of 7 is neutral

Hydrophobic vs. Hydrophilic Hydrophobic- molecules that are non polar and insoluble (fear of water) Example- lipids Hydrophilic- molecules that are polar or ionic and soluble in water (water loving) Example- Salt, Sugar

Reflection Questions 1. Why does water have the properties that it does? 2. How does the specific heat characteristics of water impact climate? 3. (T/F) Hydrogen bonds are very strong and difficult to break. 4. A solution that has a pH of ____ is an acidic solution. 5. What is the most abundant inorganic compound in your body?

Organic vs. Inorganic Organic compounds contain carbon. Two common exceptions are carbon monoxide (CO) and carbon dioxide (CO2). Carbon forms covalent bonds in single, double, triple bonds, chains, and rings. Monomer is a small single unit. Example: glucose Polymer is many small units put together. Example: starch. Polymerization is when monomers are joined to form polymers.

Essential Organic Compounds Part 2: Four Biological Molecules Essential Organic Compounds Biological Molecules are also called Macromolecules, Organic Molecules, and Organic Compounds. They are: Carbohydrates Lipids Nucleic Acids Proteins

Carbohydrates Carbohydrates are composed of carbon, hydrogen and oxygen atoms in a 1:2:1 ratio Monomers are simple sugars called a monosaccharide Combining two monosaccharides forms a disaccharide The polymer of a carbohydrate is a polysaccharide The primary function of carbohydrates is to provide quick energy Example of carbohydrates include glucose, sucrose, and starch

What role do carbohydrate play in biology? Carbohydrates are formed in the process of photosynthesis and broken down in the process of cellular respiration The break down of carbohydrates allows the cell to produces ATP molecules, the energy currency of the cell There are also carbohydrates found in the cell membrane

Storage of Carbs in Animals The carbohydrate in the food that animals eat is broken down into the simplest carbohydrate glucose.The glucose is used as fuel to carry out the processes through which an animal stays alive. When all the requirement of glucose are fulfilled, the excess glucose is stored as glycogen(a large complex molecule) in the liver so that it can be used again when required. Glycogen is also stored in muscle cells. But why as glycogen? Basically, it is a polysaccharide of glucose. Its structure allows it to be packed compactly so more of it can be stored in cells and that means less wastage. Glycogen is just a chain of glucose molecules with many branched chains:

Storage of Carbs in Plants The storage form of glucose in plants is starch. Starch is a polysaccharide. The leaves of a plant make sugar during the process of photosynthesis. Photosynthesis occurs in light (photo = light), such as when the sun is shining. The energy from the sunlight is used to make energy for the plant. So, when plants are making sugar (for fuel, energy) on a sunny day, they store some of it as starch. When the simple sugars need to be retrieved for use, the starch is broken down into its smaller components. They literally save some energy for a rainy day!

Lipids Lipids are composed of carbon, hydrogen, and oxygen but not in any ratio Lipids do not have a true monomer, but they are composed of fatty acids and glycerol Unlike other biomolecule groups, fatty acid monomers are not directly bonded to each other in polymer chains.Unlike other biomolecule groups, fatty acid monomers are not directly bonded to each other in polymer chains The primary functions of lipids include long term energy and insulation Examples of lipids include fats, oils, steroids and waxes

What role do lipids play in biology? Lipids are the primary molecules found in the cell membrane

Nucleic Acids Nucleic acids are primarily composed a phosphate group, a sugar, and a nitrogen base The primary function of nucleic acids are to store genetic information The monomer of a nucleic acid is a nucleotide Examples of nucleic acids are DNA and RNA

What role do nucleic acids play in biology? Nucleic acids are a key part of the central dogma of biology DNA is transcribed into mRNA and mRNA is translated into proteins There are three different types of RNA: mRNA tRNA rRNA

Proteins Proteins are composed of amino acids (the monomer of proteins) Proteins are the building blocks of life and have many critical functions. Some of those functions include: Speeding up chemical reactions Carrying oxygen in the blood Communication from cell to cell Expressing the genotype found in DNA

What role do proteins play in biology? Proteins are key parts of the cell membrane, perform all cellular functions, and allow cells to communicate with each other. Building blocks of life Without proteins life would not be possible

Reflection Questions 1. What organic compound speeds up reactions? 2. What type of organic compound might you eat prior to participating in a sport? 3. What is an example of a nucleic acid? 4. What type of organic compound is found in the cell membrane? 5. What type of bond is formed between two amino acids? 6. What type of organic compound is generally formed in photosynthesis?

Characteristics of Enzymes Part 3: Enzymes

Key Characteristics of Enzymes Speed up reactions by lowering activation energy of a reaction Specific enzymes are paired with specific reactions (lock and key model) The name ends with –ase

Key Terms Catalysts are molecules that increase rate of chemical reactions Substrates are molecules on which an enzyme acts. Active site is an area located on enzyme where reaction occurs. Inhibitors help regulate enzyme activity. They block the active site or distort the enzyme’s shape.

Lock and Key Mechanism

What are some things that effect the effectiveness of enzymes? pH Temperature Substrate concentration Enzyme concentration

Section 3 Check 1. What type of molecule is an enzyme? 2. (T/F) Any enzyme can speed up any reaction. 3. (T/F) Enzymes lower activation energy in a reaction. 4. Where does the substrate bond to the enzyme? 5. Why is the a lock and key a good analogy to how an enzyme interacts with a substrate?

Formation and Breakdown of Organic Compounds Dehydration Synthesis- formation of organic compounds by removing a water molecule Hydrolysis- breakdown of organic compounds by adding a water molecule