UTSA bio 1404 Exam Study Terms and Questions with Correct Verified Answers

UTSA bio 1404 Exam Study Terms and Questions with Correct Verified Answers What is the chemical behavior of an atom dependent on? - ANSWER The number of elections in its outermost shell AKA va lence electrons What are the electrons on the outermost shell called? - ANSWER Valence Electrons Valence Electron - ANSWER Electron that is associated with an atom and that can participate in the formation of a CHEMICAL BOND Atoms with incomplete valence shells - ANSWER Can SHARE or TRANSFER its electrons, therefore, creating a COVALENT BOND(S) Compound - ANSWER To form a compound, you need elements that have UNPAIRED ELECTRONS so they can share/transfer their valence electrons What are the two types of chemical bonds? - ANSWER 1. Covalent 2. Weak/Non -covalent bonds Covalent Bonds - ANSWER Sharing of a PAIR of valence electrons Molecule - ANSWER 2+ atoms being held together by valence bonds Valence - ANSWER Usually corresponds to th e number of electrons required to complete the atom. (if they're missing two, then they have two valence.) Which element almost always forms covalent bonds? - ANSWER CARBON. It shares electrons with other atoms that have similar electronegativity. Electronegativity - ANSWER 1. Atoms attract electrons to varying degrees. 2. This is an atoms particular attraction for the electrons in a covalent bond 3. The more EN, the more strongly it pulls shared electrons towards itself Most electronegative elements - ANSWER Fluorine Nitrogen Oxygen Polar - ANSWER Hydrophillic One atom is more electronegative, and the atoms do not share the electrons equally. Non -Polar - ANSWER Hydrophobic Atoms SHARE the electrons equally What causes positive/negative cha rge in an atom/molecule? - ANSWER The unequal distribution of electrons Types of non -covalent bonds? - ANSWER 1. Ionic Bond 2. Hydrogen Bond 3. Hydrophobic Interactions 4. Van der Waals Interactions Ionic Bonds - ANSWER 1. Attraction between an anion & cat ion 2. The taking/adding of two compatible atoms to give them both charges to complete their valence shell Hydrogen Bonds - ANSWER 1. Forms when hydrogen atoms covalently bonded to one electronegative atom is also attracted to another electronegative atom In living cells, the electronegative partners are usually - ANSWER Nitrogen and Oxygen Van der Waals Interactions - ANSWER 1. If electrons are distributed ASSYMETRICALLY in molecules or atoms, they can result in HOT SPOTS 2. weak and occur when atoms/ molecules are very close together 3. Collectively, can be strong Hydrophic Interactions/ Hydrogen Interaction - ANSWER Property that non -polar molecules tend to form aggrefates of like molecules in water. Hydrophobic interactins form inbetween hydrophoni c groups Chemical Reactions - ANSWER The making and breaking of chemical bonds Reactants - ANSWER Starting molecules of a chemical reaction