AP BIO penguins unit 1 TBC Exam 2023 with complete
solution
What is a hydrogen bond?
A hydrogen bond is a weak bond interaction between the negative and positive regions
of two separate molecules.
Where are hydrogen bonds found in water?
Hydrogen bonds are found between the hydrogen atom of one water molecule and the
pair of electrons on an oxygen atom of a neighboring water molecule.
Where are hydrogen bonds found in DNA?
Hydrogen bonds exist between the two strands and form between a base
How many hydrogen bonds are found between each complementary base
pairing?
-Three hydrogen bonds form between guanine and cytosine.
-Two hydrogen bonds form between adenine and thymine or adenine and uracil.
What is the structure of an amino acid?
An amino acid's structure consists of a central carbon atom, bonded to an amino group
(NH2), a carboxyl group (COOH), and to a hydrogen atom.
What are the three options for the R group?
The 3 options for the R group is a hydrophobic group, a charged and polar group, and
an uncharged polar group.
How does the polarity of the R groups work?
-Hydrophobic/polar = repels water
-Hydrophilic/nonpolar = accepts water
What are three properties of water?
The 3 properties of water consist of cohesion/adhesion, specific heat, and surface
tension.
How does hydrogen bonding allow for specific heat?
-Water's high heat capacity is a property caused by hydrogen bonding among water
molecules.
-When heat is absorbed, hydrogen bonds are broken and water molecules can move
freely.
-When the temperature of water decreases, the hydrogen bonds are formed and
release a considerable amount of energy.
How does hydrogen bonding allow for cohesion/adhesion?
-Cohesion and adhesion in water are caused by the intermolecular attraction between
the partial negative oxygen of one water molecule, and the partial positive hydrogen of
another molecule.
How does hydrogen bonding allow for surface tension?
-Water molecules form hydrogen bonds with other water molecules which are strong
and flexible.
-This creates a high surface tension.
-This molecule at the surface tends to be pulled into the bulk of the liquid and minimizes
the surface area of a liquid.
Why is water is considered a polar molecule?
solution
What is a hydrogen bond?
A hydrogen bond is a weak bond interaction between the negative and positive regions
of two separate molecules.
Where are hydrogen bonds found in water?
Hydrogen bonds are found between the hydrogen atom of one water molecule and the
pair of electrons on an oxygen atom of a neighboring water molecule.
Where are hydrogen bonds found in DNA?
Hydrogen bonds exist between the two strands and form between a base
How many hydrogen bonds are found between each complementary base
pairing?
-Three hydrogen bonds form between guanine and cytosine.
-Two hydrogen bonds form between adenine and thymine or adenine and uracil.
What is the structure of an amino acid?
An amino acid's structure consists of a central carbon atom, bonded to an amino group
(NH2), a carboxyl group (COOH), and to a hydrogen atom.
What are the three options for the R group?
The 3 options for the R group is a hydrophobic group, a charged and polar group, and
an uncharged polar group.
How does the polarity of the R groups work?
-Hydrophobic/polar = repels water
-Hydrophilic/nonpolar = accepts water
What are three properties of water?
The 3 properties of water consist of cohesion/adhesion, specific heat, and surface
tension.
How does hydrogen bonding allow for specific heat?
-Water's high heat capacity is a property caused by hydrogen bonding among water
molecules.
-When heat is absorbed, hydrogen bonds are broken and water molecules can move
freely.
-When the temperature of water decreases, the hydrogen bonds are formed and
release a considerable amount of energy.
How does hydrogen bonding allow for cohesion/adhesion?
-Cohesion and adhesion in water are caused by the intermolecular attraction between
the partial negative oxygen of one water molecule, and the partial positive hydrogen of
another molecule.
How does hydrogen bonding allow for surface tension?
-Water molecules form hydrogen bonds with other water molecules which are strong
and flexible.
-This creates a high surface tension.
-This molecule at the surface tends to be pulled into the bulk of the liquid and minimizes
the surface area of a liquid.
Why is water is considered a polar molecule?
