AP Bio - Chemistry Of Life

ions

atoms that form positive or negative charges when the lose of gain electrons

ionic bond

occurs when one atom loses an electron (e.g. sodium - Na) and another atom (e.g. chlorine) gains an electron (NaCl)

covalent bond

occurs when nonmetal atoms share electrons

polar covalent bonds

occurs when nonmetal atoms share electrons unequally (e.g oxygen and hydrogen bonded together within a molecule)

nonpolar covalent bond

occurs when nonmetal atoms share electrons equally (e.g. carbon and hydrogen bonded together within a molecule)

electronegativity

an attraction an atom has for electrons - atoms with 5, 6, or 7 valence electrons have a higher electronegativity  than atoms with 1, 2, 3 or 4 valence electrons

water is a polar molecule

one end of water (oxygen) is slightly negatively charged and the other end (hydrogen) is slightly positively charged

hydrogen bond

occurs between water molecules where between an oxygen atom on one water molecule and hydrogen atom on another water molecule

water has a high specific heat

water’s ability to resist temperature changes - when water absorbs heat - hydrogen bonds are broken, when water loses heat - hydrogen bonds form

water has a high heat of vaporization

water converting from a liquid to a gas is used as a way to help humans cool down when their body temperature increases

water is a solvent (versatile)

water’s ability to dissolve polar & ionic compounds

ice is less dense than liquid water at 0^oC

ice floats on top of liquid water; hydrogen bonds are static -not breaking down and reforming - and are spaced far apart

hydrophilic

characterizes other polar molecules (e.g. carbohydrates) that are attracted to water

hydrophobic

characterizes nonpolar molecules (e.g. lipids) that are not attracted to water

cohesion

occurs when water molecules form hydrogen bonds with other water molecules

adhesion

occurs when water molecules form hydrogen bonds with different types of molecules (e.g. xylem vessels are made of carbohydrates; water molecules form hydrogen bonds with these carbohydrates)

surface tension

because of the high number of hydrogen bonds, water resists the stretching and breaking of its surface

monomer

a building block of a polymer (e.g monosaccharide, amino acid, nucleotide)

polymer

a complex molecule made from connecting monomers together (e.g. polysaccharide, protein, nucleic acid)

hydroxyl

OH - hydrophilic functional group found in carbohydrates

phosphate

PO₄^-3 - hydrophilic functional group found in phospholipids and nucleic acids

carbonyl

C=O - hydrophilic functional group found in monosaccharides

carboxyl

COOH - hydrophilic functional group fatty acid monomer and amino acids

methyl

CH₃ - the only functional group that is hydrophobic, found in lipids

sulfhydryl

SH - hydrophilic functional group found in (some) amino acids

saturated fatty acids

a type of lipid that only has single bonds between carbon atoms

unsaturated fatty acids

a type of lipid that has one or more double bonds between carbon atoms

glycerol

added to fatty acids to make a triglyceride or phospholipid (learn molecular structure!!)

phospholipid

polymer of a lipid (learn molecular structure!!)

steroid

a lipid with 4 rings of carbon atoms (each carbon atom is bonded to one or two hydrogen atoms; C-H bond is an example of a nonpolar covalent bond)

amino acids

monomer of proteins, contains amino and carboxyl functional groups (learn molecular structure!!)

nucleotides

have hydroxyl and phosphate groups as their functional groups

what DNA and RNA nucleotides consist of

a sugar, nitrogen base, and phosphate

purines

have 2 rings of nitrogen bases (examples are adenine and guanine)

pyrimidines

have just 1 ring of nitrogen bases (examples are thymine, cytosine, and uracil)

DNA

has deoxyribose sugar (the 2nd carbon in the sugar is missing a hydroxyl group) and nitrogen bases: A, T, C, and G

RNA

has a ribose sugar (the 2nd carbon in the sugar contains a hydroxyl group) and nitrogen bases: A, U, C, and G

nucleosides

only contain a nitrogen base and a sugar

dehydration synthesis

occurs when one or more water molecules are removed from monomers so they can join together to form a polymer

hydrolysis

occurs when one or more water molecules are added to a polymer to break it down into its monomers

tryglyceride

a polymer of a lipid made of three fatty acids bonded to a glycerol

primary level of protein structure

straight chain of amino acids connected by peptide bonds to form a polypeptide chain; the peptide bonds occur between the carboxyl end of one amino acid and the amino group of another

secondary level of protein structure

polypeptide chain folds into either a beta pleated sheath or alpha helix

adenosine triphosphate (ATP)

an RNA nucleotide that serves as an energy carrying molecule for cells so they can do work

tertiary level of protein structure

polypeptide chain continues folding into a shape; folding is caused by hydrogen bonding, disulfide bridges, ionic bonding, and hydrophobic interactions at the R groups

quaternary level of protein structure

when the final protein is formed; occurs when 2 or more polypeptide chains come together; they can be joined by hydrogen, hydrophobic, or ionic bonds

C₆₀H₁₀₂O₅₁

if the molecular formula for glucose is C₆H₁₂O₆, what would be the molecular formula for a polymer made by joining 10 glucose molecules together by dehydration synthesis?