2 min read•june 18, 2024
Danna Esther Gelfand
Haseung Jun
Danna Esther Gelfand
Haseung Jun
: Sharing of electrons (Molecule created by two or more atoms in a covalent bond). A single bond (sharing one pair of electrons) in a structural formula is represented by one line connecting two atoms. A double bond is the sharing of two pairs of electrons. A structural formula is represented by two lines connecting two atoms. Electronegativity is the atom's attraction for electrons in a covalent bond.
Examples: (CH4), (CO), and (IBr).
: Transfer of electrons/electrostatic attraction between a positive and negative ion (after the transfer, both atoms have complete valence shells) (ionic compounds/salts formed).
Examples: NaCl, LiF.
are formed by the attraction between metal ions and delocalized, or "free", electrons. Examples: , , , , , , .
Polymer: a long molecule composed of many molecules bonded together covalently. (composed of multiple monomers) (Poly-many). Out of the main biological macromolecules, lipids, do not usually form polymers.
: are small building block molecules that, when combined, make a polymer. (mono-one)
: the equal sharing of electrons and distribution of charge (smaller electronegativity differences as seen in the figure above).
: Unequal sharing of electrons and distribution of charge causes partial positive or partial negative for each atom or molecule (higher electronegativity differences as seen in the image above).
It is important to note that Hydrogen bonds are NOT covalent bonds.
: occurs when monomers combine to form a polymer through a reaction after water is removed (dehydrate - water lost). One monomer donates OH- and another monomer donates H+ forming H20. It is a condensation reaction, requires energy (making it an endergonic reaction) and enzymes, and builds complexity (anabolic- small molecules bind together to form larger molecules).
: occurs when polymers are broken down into monomers through a reaction due to the addition of water (hydro - water, lysis - break) (Digestion). It uses H2O to break down the molecules splitting into H+ and OH-. Releases energy (exergonic) and requires enzymes. Reduces complexity (catabolic).
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Check out the AP Bio Unit 1 Replays or watch the 2021 Unit 1 Cram