UNIT 1 - Fundamentals & Biochemistry Objectives ● Illustrate biochemistry & explain how biology works on a molecular level ● Discuss the properties and bonds of water & assess the role it plays in cellular process ● Identify the element on which all life is built ● Categorize functional groups that bind to carbon ● Use root words to find meanings of new terms Matter Biochemistry Matter - the study of matter, its properties, & its role in living things - any substance that cannot be broken down by chemical means, has a mass and volume Compound - 2+ elements in a fixed ratio Water - Water covers 71% of Earth’s surface, it’s a molecule made of 2 hydrogen and 1 oxygen atoms in a Covalent Bond - polar covalent bond . - a bond where one atom shares electrons with another, polar or non-polar In a polar bond, there are changes in charge across a molecule, one element is more electronegative than the other. - Polar molecules interact strongly with others due to attraction of unlike charges - Hydrogen bonds give water its properties Properties of Water Cohesion - water’s ability to form hydrogen bonds with other water molecules Adhesion - water’s ability to form hydrogen bonds with other surfaces Surface tension - water near the surface is pulled towards the water below due to cohesion, this is what forms a ‘bubble’ on water’s surface Capillary action - plants move water against gravity without using energy, cohesion holds water together, adhesion allows movement against gravity Density - solid ice is less dense than liquid water because of its rigid crystal structure which increases volume while having the same mass Universal solvent - - water’s polar nature allows it to dissolve many molecules Ionic solids are hydrophilic and break apart in water, polar ends of water surround different ions and break bonds apart - Hydrophobic/hydrophilic substances are defined by their capacity to form hydrogen bonds in water - Water is most essential for living organisms due to hydrogen bonds and polarity pH and Living Organisms - Sometimes, a hydrogen atom is transferred from one water molecule to another Hydroxide Hydronium - an OH- ion, loses an H+ ion - an H3O ion, referred to as H+ usually as it gains H+ - Changes in OH- or H+ concentration can change proteins and molecules. These changes are measured in the pH pH scale . - a negative log of H+ concentration Acidic Basic - donates more H+ ions, pH between 0 and 7 - accepts more H+, pH between 7 and 14. Alkaline - - concentration of OH- ions is higher than the concentration of H+ ions pH value and H+ concentration have an opposite relationship, the higher the H+ concentration, the lower the pH Buffer - a solution with weak acidic and corresponding base, resists change in pH, and maintains pH level. - Find H+ log to calculate pH, [H+] + [OH-] = 10^-14 - i.e. if H+ = 10^-4, the pH is 4 and OH = 10^-10 Carbon - Living matter mostly consists of carbon, oxygen, hydrogen, and nitrogen. Large essential molecules are mainly composed of carbon. - Biological diversity at a molecular level results from carbon’s many molecules with different properties and shapes. - Carbon can bond to itself to create chains, chains of carbon and hydrogen are called hydrocarbons, they store energy in lipids Functional Groups Functional groups - replace 1+ hydrogen on a hydrocarbon skeleton to create new organic molecules. They can participate in chemical reactions or change the shape of a molecule Methyl (CH3) Hydroxyl (OH) - binds to DNA to change the expression of genes - polar group, forms hydrogen bonds with neighboring molecules Carbonyl (C=O) Carboxyl (COOH) -often found in sugars - donates H+, behaves as an acid Amino (NH2) - behaves as a base, accepts H+ Phosphate (P-4O) - ionized group, reacts with water to increase energy, drives the cellular process. ATP is an organic phosphate, an energy-transferring molecule in cells Root Words - Biological terms are made of common root words, prefixed and suffixed. You can use them to decipher unknown meanings of new words - Here’s a great resource on root words in science: