BIOLOGY 93 UCI MIDTERM 1 KEY TERMS 2024

BIOLOGY 93 UCI MIDTERM 1 KEY TERMS 2024 Hypothesis - answera tentative answer to a well framed question - an explanation on trial Prediction - answerA logical statement about what will happen if the hypothesis is correct. Experiment - answera repeatable procedure that is used to test a hypothesis (a scientific test carried under controlled condition) Variable - answerfactors that vary in an experiment Controlled Experiment - answerAn experiment in which all factors are identical except the one being tested. Compares an experimental group with a control group Independent Variable - answerthe factor manipulated by the researchers Dependent Variable - answera factor that is measured in the experiment Theory - answer1)Broader than a hypothesis. 2)broad enough to spin off many new hypotheses that can be tested. 3) Supported by a great body of evidence Science - answeran approach to understanding the natural world Element - answeris a chemical substance that cannot be broken down to other substances Compound - answera substance consisting of 2 or more different elements combined in a fixed ratio. Neutron - answera atomic particle that is electrically neutral (0) Proton - answera atomic particle with one unit of positive charge Electron - answera atomic particle with one unit of negative charge Atom - answersmallest unit of matter that still retains the properties of an element. Made up of a neutron/proton nucleus, and shell(s) of electrons Covalent Bond - answeris the sharing of a pair of valence electrons by two atoms. Molecule - answertwo or more atoms held together by covalent bonds constitute a molecule Single bond - answera covalent bond in which two atoms share one pair of electrons Double Bond - answera covalent bond produced by the sharing of two pairs of electrons between two atoms Valence - answerElectrons on the outermost energy level of an atom: electrons that form bonds. Electronegativity - answerAtom's ability to attract and hold electrons. Non polar Covalent Bond - answera bond where electrons are shared equally among two atoms or where symmetric structure causes polarity to cancel out. Polar Covalent Bond - answerWhere asymmetric structure and unequal sharing of electrons between two atoms with different electronegativity values create partial charges within the molecule. Ionic Bond - answerWhen an electron is attracted to another atom of higher electronegativity and the resulting charges create a ionic attraction. Ion - answerA charged atom or group of atoms that is charged due to a net loss or gain of electrons Cation - answera positively charged ion Anion - answera negatively charged ion Salt - answerA compound resulting from the formation of ionic bonds; also called an ionic compound Hydrogen Bond - answera weak interaction involving a hydrogen atom and a fluorine, oxygen, or nitrogen atom Van De Waals Interaction - answerWeak attractions between molecules due to opposite polarized electron clouds Chemical Reaction - answerthe making and breaking of chemical bonds, leading to changes in the composition of matter Reactant - answerA chemical substance that is present at the start of a chemical reaction Product - answerElement or compound produced by a chemical reaction Chemical Equilibrium - answerthe point in a reactions where the rate of the forwards reaction = the rate of the reverse reactions = no net production of products or reactants Solution - answerA that is a completely homogenous mixture of two or more substances Solvent - answerthe dissolving agent of the solution Solute - answerthe subt A substance that is dissolved in a solution. Aqueous Solution - answera solution in which the solute is dissolved in water Hydrophobic - answersubstances that are nonionic and non polar that repel water Hydrophilic - answera substance that has affinity for water due to polarity or ionic charges Hydrogen ion - answera hydrogen atom without an electron (or a proton) Hydroxide ion - answerA negatively charged ion (OH-) made of oxygen and hydrogen Hydronium Ion - answerthe positive ion formed when a water molecule gains a hydrogen ion Acid - answerAny compound that increases the concentration of hydronium ions when dissolved in water(a proton donor) Base - answerA substance that decreases the hydrogen ion concentration in a solution (proton acceptor). pH scale - answerA range of values used to express the concentration of hydrogen ions in a solution. pH = -log[H+] Buffer - answermixture that can react with an acid or a base to maintain the pH within a specific range. Prevents sharp changes in pH. Functional Group - answerchemical groups that are directly involved in chemical reactions. Each group has its own properties such as shape and charge. Hydroxyl - answerR-OH (polar, froms H bonds, helps dissolve compounds such as sugars) Carbonyl - answerKet(one)/Alde(hyde) if at end, C = O. Polar, can form hydrogen bonds. Carboxyl - answerchemical group -COOH that can donate its H (therefore acidic and polar). Present in all amino acids. Amino - answerNH2 acts as a base by accepting an H+ ions (becomes NH3+). Polar, and is present in all amino acids. Sulfhydryl - answerfunctional group, SH can form cross links that help stabilize protein structure.