UGA BIOLOGY 1107 ACTUAL EXAM
PAPER 4 QUESTIONS AND
VERIFIED SOLUTIONS GRADED A
PLUS
⩥ Explain how molecules of water interact with each other in the liquid
state. Answer: Water molecules are formed by strong polar covalent
bonds.
The molecules interact with other water molecules thru weak Hydrogen
Bonds.
⩥ Determine how other molecules interact with water based on charge
and polarity Answer: In water polarity, a polar substance that dissolves
in water is hydrophilic ("water-loving") and a non-polar that does not
interact in water/does not dissolve in water is hydrophobic ("water-
fearing").
Charges can form hydrogen bonds w/ water called a sphere of hydration.
Also ionic bonds are added to water and disrupted by dissociation which
means atoms or groups break off from molecules and form ions.
⩥ Differentiate dehydration and hydrolysis reactions in regards to
molecules of life. Answer: Dehydration ("the loss of water"): this
reaction involves the formation of new bonds and requiring energy.
,- Marco-molecules are made from molecules
- Monomers form polymers (covalent bonds)
-By the release of water the reaction is called dehydration synthesis
Hydrolysis ("to split with water"): this reaction breaks bonds and
releases energy.
- Polymers broken down into monomers and are assembled by
hydrolysis
-Polymers are broken into 2 parts: H+ (hydrogen atoms) & OH-
(hydroxyl molecule) from split water molecules
⩥ $TopHat$
A polymer composed of 100 monomers is produced through series of
dehydration reactions. How many molecules of water are generated as a
result of this process? Answer: 99 because for every 2 monomers you
join, you loose 1 polymer 1 less bond than monomers
⩥ Describe the basic structure of amino acids and identify properties of
amino acids based on the structures of their R-groups. Answer: Def of
Amino Acid: monomers that bond to form polymers called polypeptides
(a chain of amino acids = polypeptide)
Basic Structure of Amino Acid:
, -Amino group
-Carboxyl Group
-R group (diff. in each amino acid)
⩥ Explain how polypeptides are formed from bonding amino acids
together Answer: Amino acids are bonded by peptide bonds which form
dehydration reactions (and the formation of the bond is endergonic or
requires energy)
⩥ Describe how polypeptides fold into shapes Answer: Primary
Structure: the sequence of amino acids that is unique to each polypeptide
*a straight chain of amino acid* ex) pulling a phone cord straight
Secondary Structure: caused by Hydrogen bonds among amino acids in
the backbone of polypeptide (but R-groups are not involved) ex) coiled
phone cord
Tertiary Structure: caused by many bonds & interactions w/ R-Groups
ex) tangled/clumped up phone cords
Quaternary Structure: composed of two or more polypeptides; structural
is hierarchical
ex) tangling 2 cords together
PAPER 4 QUESTIONS AND
VERIFIED SOLUTIONS GRADED A
PLUS
⩥ Explain how molecules of water interact with each other in the liquid
state. Answer: Water molecules are formed by strong polar covalent
bonds.
The molecules interact with other water molecules thru weak Hydrogen
Bonds.
⩥ Determine how other molecules interact with water based on charge
and polarity Answer: In water polarity, a polar substance that dissolves
in water is hydrophilic ("water-loving") and a non-polar that does not
interact in water/does not dissolve in water is hydrophobic ("water-
fearing").
Charges can form hydrogen bonds w/ water called a sphere of hydration.
Also ionic bonds are added to water and disrupted by dissociation which
means atoms or groups break off from molecules and form ions.
⩥ Differentiate dehydration and hydrolysis reactions in regards to
molecules of life. Answer: Dehydration ("the loss of water"): this
reaction involves the formation of new bonds and requiring energy.
,- Marco-molecules are made from molecules
- Monomers form polymers (covalent bonds)
-By the release of water the reaction is called dehydration synthesis
Hydrolysis ("to split with water"): this reaction breaks bonds and
releases energy.
- Polymers broken down into monomers and are assembled by
hydrolysis
-Polymers are broken into 2 parts: H+ (hydrogen atoms) & OH-
(hydroxyl molecule) from split water molecules
⩥ $TopHat$
A polymer composed of 100 monomers is produced through series of
dehydration reactions. How many molecules of water are generated as a
result of this process? Answer: 99 because for every 2 monomers you
join, you loose 1 polymer 1 less bond than monomers
⩥ Describe the basic structure of amino acids and identify properties of
amino acids based on the structures of their R-groups. Answer: Def of
Amino Acid: monomers that bond to form polymers called polypeptides
(a chain of amino acids = polypeptide)
Basic Structure of Amino Acid:
, -Amino group
-Carboxyl Group
-R group (diff. in each amino acid)
⩥ Explain how polypeptides are formed from bonding amino acids
together Answer: Amino acids are bonded by peptide bonds which form
dehydration reactions (and the formation of the bond is endergonic or
requires energy)
⩥ Describe how polypeptides fold into shapes Answer: Primary
Structure: the sequence of amino acids that is unique to each polypeptide
*a straight chain of amino acid* ex) pulling a phone cord straight
Secondary Structure: caused by Hydrogen bonds among amino acids in
the backbone of polypeptide (but R-groups are not involved) ex) coiled
phone cord
Tertiary Structure: caused by many bonds & interactions w/ R-Groups
ex) tangled/clumped up phone cords
Quaternary Structure: composed of two or more polypeptides; structural
is hierarchical
ex) tangling 2 cords together
