BS161 2024 Updated Exam

BS161 2024 Updated Exam What type of bond occurs between molecules? - ANSWER Covalent bond Blank unwinds DNA - ANSWER Helicase DNA polymerase can only add nucleotides to the 3' end of an blank strand - ANSWER Existing What forces occur between molecules? - ANSWER Ionic, hydrogen, hydrophobic clustering and london dispersion forces Covalent bonds involve To fill outer electron shells - ANSWER Sharing of electrons. What is the goal of covalent bonding? - ANSWER To fill the outer electron shell Why do atoms want to form bonds? - ANSWER Because when they form bonds they go to a lower energy stat which makes them more stable. What type of bonds does water have? - ANSWER Polar covalent bonds In a water molecule which part has a partial positive charge? - ANSWER The hydrogens In a water molecule, which part has a partial negative charge? - ANSWER Oxygen Why does oxygen have a partial negative charge in water? - ANSWER The electrons are more concentrated around the oxygen atom and they have a negative charge. In a polar covalent bond are electrons shared equally or not equally? - ANSWER Not equally In a water molecule why do the electrons spend more time around the oxygen instead of the hydrogens? - ANSWER Because oxygen is more electronegative What are two popular electronegative atoms seen in biology? - ANSWER Oxygen and nitrogen Atoms like nitrogen and oxygen most likely indicate a - ANSWER Polar covalent bond When do polar covalent bonds occur? - ANSWER When there is a difference in electronegativity Which is more electronegative oxygen or hydrogen? - ANSWER Oxygen Which is more electronegative nitrogen or carbon? - ANSWER Nitrogen Rank the following molecules by electronegativities largest to smallest: C, N, O, H - ANSWER O,N,C is about the same as H Bonds that include nitrogen or oxygen are nearly always - ANSWER Polar What is the relative strength of covalent bonds? - ANSWER Strong When a bond forms energy is - ANSWER Released When a bond breaks energy is - ANSWER Required Compared to covalent bonds, hydrogen and ionic bonds are - ANSWER Weak Compared to hydrophobic and LDFs, hydrogen and ionic forces are - ANSWER Stronger Ionic bond interactions occur between - ANSWER Oppositely charged ions In an ionic force electrons are - ANSWER Not shared When two ions interact in a ionic force they're individual charges - ANSWER Remain What does a hydrogen bond interaction occur between? - ANSWER A partially charged hydrogen and a more electronegative atom. What are the two requirements for a hydrogen bond force to form? - ANSWER Needs a partial positive H and a partial negative O or N Molecules with polar covalent bonds are also called - ANSWER Polar uncharged Collectively hydrogen bonds can have a - ANSWER Strong influence on the behavior of molecules Molecules that interact with water are - ANSWER Hydrophilic Molecules that don't interact with water are - ANSWER Hydrophobic Substances that interact with water are more likely to be - ANSWER Soluble in water