BIOL 240 EXAM 1 QUESTIONS &
ANSWERS(GRADED A+)
Name the essential elements in living organisms. - ANSWERcarbon, hydrogen, oxygen,
nitrogen
Definition of a cell. - ANSWERThe smallest living unit
Definition of an atom. - ANSWERthe smallest nonliving unit
How to determine an atom's mass number? - ANSWERnumber of protons + neutrons in
the nucleus
how to determine an atom's atomic number? - ANSWERnumber of protons
how to determine the number of valence electrons if given total number of electrons? -
ANSWERlook at the main group number
what does the bottom number around an element's symbol mean? - ANSWERatomic
number
what does the top number around an element's symbol mean? - ANSWERatomic mass
number
what is an isotope and what is different between isotopes? - ANSWERforms of the
same element with same number of protons, just different number of neutrons, which
makes a different mass number. they have the same chemical properties
what is an example of how isotopes can be used in real-life? - ANSWERradioactive
isotopes are often used as diagnostic tools in medicine. these isotopes are incorporated
into biologically active molecules, which are then used as tracers to track atoms during
metabolism.
describe a polar covalent bond. - ANSWERunequal sharing of electrons; they have very
different electronegativities
describe a non polar covalent bond. - ANSWERequal sharing of electrons; similar
electronegativities
describe an ionic bond. - ANSWERa bond that transfers electrons and are held together
by different charges
C-H bond type? - ANSWERnon polar covalent
, C-N bond type? - ANSWERpolar covalent bond
C-O bond type? - ANSWERpolar covalent bond
C-F bond type? - ANSWERpolar covalent bond
define hydrogen bonding. - ANSWERthe charge based attraction between a partially (+)
hydrogen and a partially (-) Fluorine, Nitrogen, or Oxygen atom
definition of hydrophobic. - ANSWERmolecules that do not have charges and cannot
easily interact with water molecules (oil)
definition of hydrophilic. - ANSWERmolecules that have partial and/or full charges that
allow them to interact with the partial charges in water molecules (sugar)
describe water as a solvent. - ANSWERwater is the solvent of life; water is polar so only
polar things can dissolve in it
definition of adhesion. - ANSWERwater bonded to something else
definition of cohesion. - ANSWERwater bonded to water
definition of moderation of temperature in water. - ANSWERwater moderates air
temperatures by absorbing heat from air that is warmer and releasing the stored heat to
the air that is cooler.
definition of expansion upon freezing in water. - ANSWERwhen water becomes solid,
water becomes less dense and expands. this is a result of hydrogen bonding.
pH range of an acid. - ANSWERless than 7
pH range of a base. - ANSWERgreater than 7
pH of a solution's equation. - ANSWER-log[H+]
pOH of a solution's equation. - ANSWER-log[OH-]
what is a buffer? - ANSWERa substance that minimizes changes in the concentrations
of H+ or OH- in a solution
pH + pOH= - ANSWER14
do lipids have true polymers? - ANSWERno
ANSWERS(GRADED A+)
Name the essential elements in living organisms. - ANSWERcarbon, hydrogen, oxygen,
nitrogen
Definition of a cell. - ANSWERThe smallest living unit
Definition of an atom. - ANSWERthe smallest nonliving unit
How to determine an atom's mass number? - ANSWERnumber of protons + neutrons in
the nucleus
how to determine an atom's atomic number? - ANSWERnumber of protons
how to determine the number of valence electrons if given total number of electrons? -
ANSWERlook at the main group number
what does the bottom number around an element's symbol mean? - ANSWERatomic
number
what does the top number around an element's symbol mean? - ANSWERatomic mass
number
what is an isotope and what is different between isotopes? - ANSWERforms of the
same element with same number of protons, just different number of neutrons, which
makes a different mass number. they have the same chemical properties
what is an example of how isotopes can be used in real-life? - ANSWERradioactive
isotopes are often used as diagnostic tools in medicine. these isotopes are incorporated
into biologically active molecules, which are then used as tracers to track atoms during
metabolism.
describe a polar covalent bond. - ANSWERunequal sharing of electrons; they have very
different electronegativities
describe a non polar covalent bond. - ANSWERequal sharing of electrons; similar
electronegativities
describe an ionic bond. - ANSWERa bond that transfers electrons and are held together
by different charges
C-H bond type? - ANSWERnon polar covalent
, C-N bond type? - ANSWERpolar covalent bond
C-O bond type? - ANSWERpolar covalent bond
C-F bond type? - ANSWERpolar covalent bond
define hydrogen bonding. - ANSWERthe charge based attraction between a partially (+)
hydrogen and a partially (-) Fluorine, Nitrogen, or Oxygen atom
definition of hydrophobic. - ANSWERmolecules that do not have charges and cannot
easily interact with water molecules (oil)
definition of hydrophilic. - ANSWERmolecules that have partial and/or full charges that
allow them to interact with the partial charges in water molecules (sugar)
describe water as a solvent. - ANSWERwater is the solvent of life; water is polar so only
polar things can dissolve in it
definition of adhesion. - ANSWERwater bonded to something else
definition of cohesion. - ANSWERwater bonded to water
definition of moderation of temperature in water. - ANSWERwater moderates air
temperatures by absorbing heat from air that is warmer and releasing the stored heat to
the air that is cooler.
definition of expansion upon freezing in water. - ANSWERwhen water becomes solid,
water becomes less dense and expands. this is a result of hydrogen bonding.
pH range of an acid. - ANSWERless than 7
pH range of a base. - ANSWERgreater than 7
pH of a solution's equation. - ANSWER-log[H+]
pOH of a solution's equation. - ANSWER-log[OH-]
what is a buffer? - ANSWERa substance that minimizes changes in the concentrations
of H+ or OH- in a solution
pH + pOH= - ANSWER14
do lipids have true polymers? - ANSWERno
