Biology 101 Exam 1 UNC with Correct Solutions 2024

Biology 101 Exam 1 UNC with Correct Solutions 2024 Molecules - Answer -A molecule is a group of atoms held together by chemical bonds that store potential energy. A molecule is formed by 2 to several dozens of atoms Some molecules have large amounts of potential energy (PF) in their chemical bonds, they serve as "Energy Molecules" that provide kinetic energy for all cell activities when their chemical bonds are broken. Adenosine Triphosphate (ATP) - Answer -Is a universal energy molecule found in almost all living organisms Macromolecule - Answer -A macromolecule is formed by hundreds or thousands of atoms Chemical bonding's: Ionic Bonds - Answer -Formed by atoms being attracted to each other due to opposite electrical charges. • A cation (positive charge) and an anion (negative charge) are usually involved in ionic bonds. (e.g. Na++ Cl-→ NaCl). Chemical Bonding's: Covalent bonds - Answer -Formed by the sharing of electrons between 2 atoms (e.g. H2O). • Atoms that form covalent bonds not only gain extra potential energy, they become more stable because of more electrons on outer orbits. • Strongest type of chemical bonding in biological molecules • Allowing cells to build larger molecules and macromolecules. *Very strong bond; very difficult to break but once broken it releases lots of energy. Electronegativity - Answer -The attraction of an atom for sharedelectrons. If the atoms in a molecule have SIMILAR electronegativity, the electrons remain equally stored between 2 nuclei and the covalent bond is said to be NON-POLAR. If one element is more electronegative, it pulls the shared electrons closer to itself, creating POLAR covalent bond. Chemical Bonding's: Hydrogen Bonds - Answer -Weakest chemical bond; but very important bc it plays a key role in forming internal shaping and folding of larger molecules.; can break and be remade again. • Hydrogen atoms contain only 1 proton and 1 electron, as a result when it is sharing its electron with another atom, it has a partial positive charge (i.e. H+). • H+ tends to be attracted to the partial negative charge of oxygen (O-) and nitrogen (N-), form