BIOL 1P91 Midterm Verified Questions With Answers

BIOL 1P91 Midterm Verified Questions With Answers Matter - ANSWER anything that has mass and occupies space States of matter - ANSWER solid, liquid, gas Atoms - ANSWER smallest functional units of matter that form all chemical substances Atoms cannot breakdown further into substances by ordinary means (will not happen in biological systems) - ANSWER true subatomic particles - ANSWER protons (+), neutrons (neutral), electrons (-) model of an atom - ANSWER Nucleus surrounded by cloud like orbitals Orbitals (types) - ANSWER S - orbitals are spherical (2e-) P - orbitals are propeller/dumbbell shaped (6e-) Electron Shells - ANSWER 1st shell (spherical): 2 electrons (1 pair) 2nd shell (3 dumbbell): 8 electrons (3 pairs) Dalton - ANSWER unit of atomic mass (amu or Da) hydrogen, oxygen, nitrogen, carbon - ANSWER What are the four most abundant elements found in living systems? (95% of living organisms) Molecule - ANSWER A group of atoms bonded together Compound - ANSWER a molecule that is composed of two or more separate elements 3 types of bonds - ANSWER ionic, covalent, hydrogen ionic bond - ANSWER electrons are transferred, forming ions that are attracted to each other (cations and anions) covalent bond - ANSWER electrons are shared to fill valence shells (double and triple bonds) hydrogen bond - ANSWER hydrogen atom from one polar molecule is attracted to an electronegative atom from another molecule Nonpolar and Polar Covalent Bonds - ANSWER _____________ _____________bonds are a type of chemical bond where two atoms share a pair of electrons with each other ____________covalent bonding is a type of chemical bond where a pair of electrons is unequally shared between two atoms. Enzymes - ANSWER molecules that catalyze biologically important chemical reactions van der Waals dispersion forces - ANSWER attractive forces between molecules in close proximity to each other, caused by the variations in the distribution of electron density around individual atoms