BIO 172 LECTURES 1 + EXAM QUESTIONS AND
ANSWERS
organismal review
life is unique in that it imposes order and predictability; molecules are more complex than abiotic
ones
Schrodinger
organisms increase order within themselves by increasing disorder in the environment
cell theory / evolution by natural selection
all species are descended from a single common ancestor at a root; the root arose from things not
previously alive
the tree of life
all life on earth is passed down with modification and generated by living things
phylogeny
comparison of genetic information that makes up evolutionary relationships between organisms
universal tree of life
archaea and eukarya are more closely related than bacteria; they show similarities in regulating
gene expression
eukaryotes
membrane bound nucleus, uni/multi cellular
prokaryotes
unicellular, no membrane bound nucleus, archaea and bacteria have similar cellular organization
nonpolar covalent bonds
equal sharing of electrons, all C-H bonds, can't make strong charge interactions
polar covalent bonds
unequal share (dipole moment), partial charges, eneg difference >0.4
ionic bonds
result of full charge interactions between atoms or molecules
Hydrogen bonds
result of partial charges on molecules with polar covalent bonds (charge interactions)
, van der waals
occur between nonpolar molecules, transient hot spots of +- charge in a molecule with nonpolar
covalent bonds (charge interaction)
covalent bonds
stronger than any other interactions
stability of bonds
bond strength + bond amount
water as a solvent
life originated and is based on water, universal solvent bc HO bonds are polar covalent, giving
water internal properties to bond to each other
hydrogen bonds in water
hbonds between water and other polar molecules help the substances stay in solution
cohesion and adhesion
explain why a meniscus forms where water meets a solid surface (result of 2 forces)
cohesion
surfaces sticking to themself, downward pull of water molecules Hbonding to each other
adhesion
tendency of dissimilar surfaces to cling to each other (water and glass resisting downward pull of
cohesion)
water has high surface tension
light objects don't fall through water's surface
buffer
minimizes changes in H
thermodynamically favored
aggregation of hydrophobic molecules in aqueous solution
aggregation of hydrophobic molecules in aqueous solution
surface area of nonpolar molecules to water decreases, fewer H2O molecules are forced into
cages and free to hydrogen bond
amino group
acts as a base, tends to attract protons
ANSWERS
organismal review
life is unique in that it imposes order and predictability; molecules are more complex than abiotic
ones
Schrodinger
organisms increase order within themselves by increasing disorder in the environment
cell theory / evolution by natural selection
all species are descended from a single common ancestor at a root; the root arose from things not
previously alive
the tree of life
all life on earth is passed down with modification and generated by living things
phylogeny
comparison of genetic information that makes up evolutionary relationships between organisms
universal tree of life
archaea and eukarya are more closely related than bacteria; they show similarities in regulating
gene expression
eukaryotes
membrane bound nucleus, uni/multi cellular
prokaryotes
unicellular, no membrane bound nucleus, archaea and bacteria have similar cellular organization
nonpolar covalent bonds
equal sharing of electrons, all C-H bonds, can't make strong charge interactions
polar covalent bonds
unequal share (dipole moment), partial charges, eneg difference >0.4
ionic bonds
result of full charge interactions between atoms or molecules
Hydrogen bonds
result of partial charges on molecules with polar covalent bonds (charge interactions)
, van der waals
occur between nonpolar molecules, transient hot spots of +- charge in a molecule with nonpolar
covalent bonds (charge interaction)
covalent bonds
stronger than any other interactions
stability of bonds
bond strength + bond amount
water as a solvent
life originated and is based on water, universal solvent bc HO bonds are polar covalent, giving
water internal properties to bond to each other
hydrogen bonds in water
hbonds between water and other polar molecules help the substances stay in solution
cohesion and adhesion
explain why a meniscus forms where water meets a solid surface (result of 2 forces)
cohesion
surfaces sticking to themself, downward pull of water molecules Hbonding to each other
adhesion
tendency of dissimilar surfaces to cling to each other (water and glass resisting downward pull of
cohesion)
water has high surface tension
light objects don't fall through water's surface
buffer
minimizes changes in H
thermodynamically favored
aggregation of hydrophobic molecules in aqueous solution
aggregation of hydrophobic molecules in aqueous solution
surface area of nonpolar molecules to water decreases, fewer H2O molecules are forced into
cages and free to hydrogen bond
amino group
acts as a base, tends to attract protons
