Bio 1107: Chapter 3- Protein Structure and Function ||
(Needed to Pass) Confirmed A+.
Define Amino Acids correct answers Amino acids are the building blocks of proteins, and
proteins are vital, as they are tremendously versatile components of today's cells.
Proteins are composed of 20 different building blocks, known as the amino acids.
In all 20 amino acids, a central carbon atom bonds covalently to the four different atoms or
groups of atoms... correct answers H - a hydrogen atom
NH2 - An amino functional group
COOH- A carboxyl functional group
A distinctive "R-group" (often referred to as a side chain)
In water, amino acids do what? correct answers In water, amino acids Ionize. The concentration
of protons at this ph causes the amino acid group to act as a base and it attracts a protons to form
NH3+.
How does the carboxyl group act correct answers The carboxyl group acts as an acid. The two
highly electronegative oxygen atoms in this group pull the electron away from its hydrogen
atom, which means that it is relatively easy for this group to lose a proton to form COO-
Why are the charges of the amino acids and carboxyl groups important? correct answers The
charges of these groups are important for two reason:
They help amino acids stay in solution where they can interact with one another and with other
solutes
They affect the amino acid's chemical reactivity.
Define R-group correct answers The R-group, or side chain, represents the part of the amino acid
core structure that makes each of the 20 different amino acids unique.
The properties of amino acids vary because their R-groups vary.
What do several of the side chains contain and what are their purpose? correct answers Several
side chains contain carbonyl, sulfhydryl, hydroxyl or amino functional groups.
Under the right conditions, these functional groups can participate in chemical reactions.
Ex. Amino acids with sulfhydryl group in their side chain can form disulfide bonds that help link
different parts of large proteins.
, Some amino acids also contain side chains that are devoid of functional groups-- consisting
solely of carbon and hydrogen atoms. These groups rarely participate in chemical reactions. As a
result, these merely influence amino acids depending on their size and shape rather than
reactivity.
Are polar R-groups hydrophilic or hydrophobic? correct answers Both polar and electrically
charged R Groups interact readily with water and are hydrophilic. Hydrophilic R- Groups
dissolve easily in water.
Are nonpolar R groups hydrophobic or hydrophilic? correct answers Nonpolar R Groups lack
charged or highly electronegative atoms capable of forming hydrogen bonds with water. These
groups are hydrophobic, meaning that they do not interact with water. INstead, they tend to
coalesce in aqueous solution.
Amino Acid R-groups are either... correct answers Amino acid R-groups are either charged,
which includes acidic and basic; uncharged polar; and nonpolar.
Does the R-group have a negative charge? correct answers If so, it is acidic and will lose a
proton, like aspartate.
Does the R-group have a positive charge? correct answers If so, it is basic and will pick up a
proton, like lysine.
If the R-group is uncharged, does it have an oxygen atom? correct answers If so, then the highly
electronegative oxygen will form a polar covalent bond in the R-group, thus making it uncharged
polar like serine.
Define macromolecules correct answers Proteins are macromolecules-- large molecules made up
of smaller molecular subunits joined together.
Define Monomers correct answers A molecular subunit used to build a macromolecule is called a
monomer.
Define Polymer correct answers When a large number of monomers are bonded together, the
resulting structure is called a polymer.
Define Polymerization correct answers The process of linking monomers together is called
polymerization.
The polymerization reaction organizes multiple simpler monomers into a single more complex
and ordered structure.
Polymerization decreases the disorder, or entropy, of the molecules involved.
(Needed to Pass) Confirmed A+.
Define Amino Acids correct answers Amino acids are the building blocks of proteins, and
proteins are vital, as they are tremendously versatile components of today's cells.
Proteins are composed of 20 different building blocks, known as the amino acids.
In all 20 amino acids, a central carbon atom bonds covalently to the four different atoms or
groups of atoms... correct answers H - a hydrogen atom
NH2 - An amino functional group
COOH- A carboxyl functional group
A distinctive "R-group" (often referred to as a side chain)
In water, amino acids do what? correct answers In water, amino acids Ionize. The concentration
of protons at this ph causes the amino acid group to act as a base and it attracts a protons to form
NH3+.
How does the carboxyl group act correct answers The carboxyl group acts as an acid. The two
highly electronegative oxygen atoms in this group pull the electron away from its hydrogen
atom, which means that it is relatively easy for this group to lose a proton to form COO-
Why are the charges of the amino acids and carboxyl groups important? correct answers The
charges of these groups are important for two reason:
They help amino acids stay in solution where they can interact with one another and with other
solutes
They affect the amino acid's chemical reactivity.
Define R-group correct answers The R-group, or side chain, represents the part of the amino acid
core structure that makes each of the 20 different amino acids unique.
The properties of amino acids vary because their R-groups vary.
What do several of the side chains contain and what are their purpose? correct answers Several
side chains contain carbonyl, sulfhydryl, hydroxyl or amino functional groups.
Under the right conditions, these functional groups can participate in chemical reactions.
Ex. Amino acids with sulfhydryl group in their side chain can form disulfide bonds that help link
different parts of large proteins.
, Some amino acids also contain side chains that are devoid of functional groups-- consisting
solely of carbon and hydrogen atoms. These groups rarely participate in chemical reactions. As a
result, these merely influence amino acids depending on their size and shape rather than
reactivity.
Are polar R-groups hydrophilic or hydrophobic? correct answers Both polar and electrically
charged R Groups interact readily with water and are hydrophilic. Hydrophilic R- Groups
dissolve easily in water.
Are nonpolar R groups hydrophobic or hydrophilic? correct answers Nonpolar R Groups lack
charged or highly electronegative atoms capable of forming hydrogen bonds with water. These
groups are hydrophobic, meaning that they do not interact with water. INstead, they tend to
coalesce in aqueous solution.
Amino Acid R-groups are either... correct answers Amino acid R-groups are either charged,
which includes acidic and basic; uncharged polar; and nonpolar.
Does the R-group have a negative charge? correct answers If so, it is acidic and will lose a
proton, like aspartate.
Does the R-group have a positive charge? correct answers If so, it is basic and will pick up a
proton, like lysine.
If the R-group is uncharged, does it have an oxygen atom? correct answers If so, then the highly
electronegative oxygen will form a polar covalent bond in the R-group, thus making it uncharged
polar like serine.
Define macromolecules correct answers Proteins are macromolecules-- large molecules made up
of smaller molecular subunits joined together.
Define Monomers correct answers A molecular subunit used to build a macromolecule is called a
monomer.
Define Polymer correct answers When a large number of monomers are bonded together, the
resulting structure is called a polymer.
Define Polymerization correct answers The process of linking monomers together is called
polymerization.
The polymerization reaction organizes multiple simpler monomers into a single more complex
and ordered structure.
Polymerization decreases the disorder, or entropy, of the molecules involved.
