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An |atom |in |a |molecule |with |a |high |electronegativity |will |hold |the |electrons
|more |tightly |and |have |a |partial______ |charge? |- |correct |answer |-✔negative |( δ -)
Nonpolar |covalent |bond: |- |correct |answer |-✔Electrons |are |evenly |shared |between |two |atoms |and |the |bond |is |symmetrical.
Polar |covalent |bond: |- |correct |answer |-✔Electrons |are |asymmetrically |shared.
Cation: |- |correct |answer |-✔An |atom |that |loses |an |electron |and |becomes |positively |charged.
Anion: |- |correct |answer |-✔An |atom |that |gains |an |electron |and |becomes |negatively |charged.
an |ion |- |correct |answer |-✔An |atom |or |molecule |that |carries |a |charge
ionic |bond |- |correct |answer |-✔The |resulting |attraction |between |oppositely |charged |ions
Chemical |reactions |occur |when: |- |correct |answer |-✔1. |One |substance |is |combined |with |another. |
Atoms |are |rearranged |in |molecules, |or |small |molecules |combine |to |form |larger |molecules. |
- |One |substance |is |broken |down |into |another |substance. |
Molecules |are |split |into |atoms |or |smaller |molecules.
The |molecular |weight |of |a |molecule |- |correct |answer |-✔The |sum |of |the |mass |numbers |of |all |the |atoms |in |the |molecule.
One |mole |- |correct |answer |-✔6.022 |x |10^23 |molecules
(a |mass |equal |to |the |molecular |weight |expressed |in |grams)
molarity |(M) |- |correct |answer |-✔the |number |of |moles |per |liter.
Water |is |- |correct |answer |-✔polar
hydrophobic |- |correct |answer |-✔Uncharged |and |nonpolar |compounds |do |not |dissolve |in |water
hydrophilic |- |correct |answer |-✔Ions |and |polar |molecules |stay |in |solution |because |of |their |interactions |with |water's |partial |charges.
pH |expresses |- |correct |answer |-✔proton |concentration |in |a |solution.
Acids |have |a |pH |of |- |correct |answer |-✔less |than | 7
(This |capacity |exists |in |one |of |two |ways — as |a |stored |potential |or |as |an |active |motion)
Stored |energy |is |- |correct |answer |-✔potential |energy
The |energy |of |movement |is |called |- |correct |answer |-✔kinetic |energy |or |thermal |energy
Electrons |in |an |outer |shell |(farther |from |the |positively |charged |nucleus) |have |______ |potential |energy |than |do |electrons |in |an |inner |shell. |- |correct |answer |-
✔more
Heat |- |correct |answer |-✔the |thermal |energy |transferred |between |objects |of |different |temperatures.
The |first |law |of |thermodynamics |states |- |correct |answer |-✔energy |is |conserved — it |cannot |be |created |or |destroyed, |but |it |can |be |transferred |or |transformed.
The |spontaneity |of |a |reaction |is |determined |by |two |factors: |- |correct |answer |-
✔1. |The |amount |of |potential |energy
- |The |order |of |degree
Entropy |(S) |- |correct |answer |-✔the |amount |of |disorder |in |a |group |of |molecules.
The |second |law |of |thermodynamics |states |- |correct |answer |-✔entropy |always |increases. |
(chemical |reactions |result |in |products |with |less |ordered |(usable) |energy)
The |Gibbs |free-energy |change | (ΔG) |- |correct |answer |-✔determines |whether |a |reaction |is |spontaneous |or |requires |energy.
ΔG |< | 0 |is |an |exergonic |spontaneous |reaction.
ΔG |> | 0 |is |an |endergonic |reaction |that |requires |energy |input.
ΔG |= | 0 |is |a |reaction |that |is |at |equilibrium.
The |Nature |of |Side |Chains |- |correct |answer |-✔The | 20 |amino |acids |differ |only |in |the |unique |R-group |attached |to |the |central |carbon. |The |properties |of |amino |acids |vary |because |their |R-groups |vary.
monomers |- |correct |answer |-✔mid-size |molecules, |such |as |amino |acids |and |nucleotides
polymers |- |correct |answer |-✔link |together |(polymerize) |to |form |larger |molecules, |such |as |proteins |and |nucleic |acids
Macromolecules |- |correct |answer |-✔very |large |polymers |made |up |of |many |monomers |linked |together.
Polymerization |- |correct |answer |-✔requires |energy |and |is |nonspontaneous.
Monomers |polymerize |through |- |correct |answer |-✔condensation |(dehydration) |reactions, |which |release |a |water |molecule.
-Structure |- |structural |proteins |define |cell |shape |and |comprise |body |structures.
-Transport |- |transport |proteins |carry |materials; |membrane |proteins |control |molecular |movement |into |and |out |of |the |cell.
A |protein's |primary |structure |- |correct |answer |-✔its |unique |sequence |of |amino |acids.
a |protein's |secondary |structure |- |correct |answer |-✔Hydrogen |bonds |between |the |carbonyl |group |of |one |amino |acid |and |the |amino |group |of |another
A |polypeptide |must |bend |to |allow |this |hydrogen |bonding, |forming: |- |correct
|answer |-✔-alpha |helices |
-beta |pleated |sheets
The |tertiary |structure |of |a |polypeptide |- |correct |answer |-✔interactions |between |R-groups |or |between |R-groups |and |the |peptide |backbone.
R-group |Interactions |That |Form |Tertiary |Structures |- |correct |answer |-✔- Hydrogen |bonds |form |between |hydrogen |atoms |and |the |carbonyl |group |in |the |peptide-bonded |backbone, |and |between |hydrogen |and |negatively |charged |atoms |in |side |chains. |
-Hydrophobic |interactions |within |a |protein |increase |stability |of |surrounding |water |molecules |by |increasing |hydrogen |bonding.
-van |der |Waals |interactions |are |weak |electrical |interactions |between |hydrophobic |side |chains. |
-Covalent |disulfide |bonds |form |between |sulfur-containing |R-groups. |
-Ionic |bonds |form |between |groups |that |have |full |and |opposing |charges.
Quaternary |Structure |- |correct |answer |-✔Many |proteins |contain |several |distinct |polypeptide |subunits |that |interact |to |form |a |single |structure; |the |bonding |of |two |or |more |subunits |produces |quaternary |structure.
Prions |- |correct |answer |-✔improperly |folded |forms |of |normal |proteins |that |are |present |in |healthy |individuals.
Enzymes |perform |two |functions: |- |correct |answer |-✔1. |Bring |substrates |together |in |precise |orientation |so |that |the |electrons |involved |in |the |reaction |can |interact
- |Decrease |the |amount |of |kinetic |energy |reactants |must |have |for |the |reaction |to |proceed
The |activation |energy |(Ea) |of |a |reaction |- |correct |answer |-✔the |amount |of |free |energy |required |to |reach |the |intermediate |condition, |or |transition |state.
A |catalyst |- |correct |answer |-✔a |substance |that |lowers |the |activation |energy |of |a |reaction |and |increases |the |rate |of |the |reaction.
A |condensation |reaction |forms |- |correct |answer |-✔a |phosphodiester |linkage |(phosphodiester |bond) |between |the |phosphate |group |on |the | 5 ′ |carbon |of |one |nucleotide |and |the |-OH |group |on |the | 3 ′ |carbon |of |another.
DNA |strands |run |in |an |- |correct |answer |-✔antiparallel |configuration.
The |primary |structure |of |RNA |differs |from |DNA |in |two |ways: |- |correct |answer |-
✔1. |RNA |contains |uracil |instead |of |thymine.
- |RNA |contains |ribose |instead |of |deoxyribose. |
The |presence |of |the |-OH |group |on |ribose |makes |RNA |much |more |reactive |and |less |stable |than |DNA.
RNA's |Secondary |Structure |- |correct |answer |-✔RNA's |secondary |structure |results |from |complementary |base |pairing. |
The |RNA |strand |folds |over, |forming |a |hairpin |structure: |the |bases |on |one |side |of |the |fold |align |with |an |antiparallel |RNA |segment |on |the |other |side |of |the |fold.
Polysaccharides |- |correct |answer |-✔or |complex |carbohydrates, |are |polymers |of |monosaccharide |monomers.
The |simplest |polysaccharides |are |- |correct |answer |-✔disaccharides, |comprised |of |two |monosaccharide |monomers.
A |glycosidic |linkage |- |correct |answer |-✔Simple |sugars |polymerize |when |a |condensation |reaction |occurs |between |two |hydroxyl |groups
Types |of |Polysaccharides |- |correct |answer |-✔1. |Plants |store |sugar |as |starch.
Mixture |of |branched |(amylopectin) |and |unbranched |(amylose) |-glucose |polymer
- |Animals |store |sugar |as |glycogen.
Highly |branched |-glucose |polymer
- |Cellulose |is |a |structural |polymer |found |in |plant |cell |walls.
Polymer |of |-glucose |monomers
- |Chitin |is |a |structural |polymer |found |in |fungi |cell |walls, |some |algae, |and |many |animal |exoskeletons.
Comprised |of |N-acetylglucosamine |(NAc) |monomers
- |Bacterial |cell |walls |get |structural |support |from |peptidoglycan.
Backbones |of |alternating |monosaccharides
glycoproteins |- |correct |answer |-✔proteins |joined |to |carbohydrates |by |covalent |bonds.
Glycoproteins |are |key |molecules |in |cell-cell |recognition |and |cell-cell |signaling.
The |three |most |important |types |of |lipids |found |in |cells: |- |correct |answer |-✔1. |Fats |are |composed |of |three |fatty |acids |linked |to |glycerol.
Also |called |triacylglycerols |or |triglycerides
Peripheral |proteins |- |correct |answer |-✔found |only |on |one |side |of |the |membrane
Integral |proteins |- |correct |answer |-✔amphipathic |and |so |can |span |a |membrane, |with |segments |facing |both |its |interior |and |exterior |surfaces.
transmembrane |proteins |- |correct |answer |-✔Integral |proteins |that |span |the |membrane
three |broad |classes |of |transport |proteins |- |correct |answer |-✔1. |Channels
- |Carrier |proteins |or |transporters
- |Pumps
