lOM oAR c P S D | 2527 011 4
CHEM 120 WEEK 7
• Select all that apply. Which of the following are typically solids at room temperature?
a. Polyunsaturated lipids
b. Trans lipids
c. Monounsaturated lipids
d. Saturated lipids
e. Unsaturated lipids
Both saturated fats and trans fats are solids at room temperature due to their linear structures.
• Which class of lipids is found in cell membranes?
a. Sterols
b. Triacylglycerol
c. Glycerolphospholipid
d. Steroids and Triacylglycerol
e. Steroids and Glycerolphospholipid
Glycerophospholipids make up the majority of the cell membrane, and sterols such as cholesterol
are also found in the membrane and used for stability.
• What type of linkage is found in triacylglycerols?
a. Glycoside
b. Ether
c. Amide
d. peptide
e. Ester
Tryiacylglycerols have ester linkages between the glycerol and fatty acids.
• Which of the following is true for both saturated and unsaturated fatty acids?
a. Both contain carboxylic acid groups
b. Both are solid at room temperature
c. Both are considered alkenes
d. Both are soluble in water
e. Both contain ester linkages
Both saturated and unsaturated fatty acids are monomers that contain a carbon chain and a
carboxylic acid group.
• Triacylglycerols contain .
a. 1 molecule of glycerol and 3 steroids
b. 3 molecules of glycerol and 1 molecule of fatty acid
c. 1 molecule of glycerol and 3 molecules of fatty acid
d. 3 molecules of glycerol and 1 steroid
Triacylglycerols are made of 1 molecule of glycerol and 3 fatty acids.
, lOM oAR c P S D | 2527 011 4
Proteins
• Rank the levels of protein structure from top (least complex/structured) to bottom (most
complex/structured).
a. Secondary – alpha helices, beta strands, and loops
b. Quaternary – interaction of multiple tertiary structures
c. Primary – sequence of amino acids
d. Tertiary – the three dimensional structure
The levels of protein structure in order of complexity are: primary, secondary, tertiary, and
quaternary.
• Examples of proteins include
a. meat and muscle
b. sugars and candy
c. butter and oil
d. all of these
Meat and muscle are example of proteins.
• Answer the following questions about the structure of amino acids.
Question
The backbone of an amino acid refers to all of the following except
a. the amine.
b. the carboxylic acid.
c. the sidechain.
d. the alpha carbon.
Question
Select all that apply. What functional groups are found in amino acids?
a. Alkene
b. Amine
c. Ester
d. Hydroxyl
e. Carboxylic acid
Question
Alpha carbons are always bound to
a. the amine.
b. a hydrogen.
c. the carboxylic acid.
d. the sidechain.
e. All of these.
Question 1 Feedback
The backbone is the portion of the amino acids that is consistent in each of the 20 amino acids. This
includes the amine, the alpha carbon, and the carboxylic acid. The sidechain will be different for
each amino acid, so that is not part of the backbone.
, lOM oAR c P S D | 2527 011 4
Question 2 Feedback
Amino acids all contain amine and carboxylic acid functional groups.
Question 3 Feedback
Alpha carbons are the center of the amino acid, bound to an H, the amine, the acid, and the
sidechain.
• Dipeptide
Locate these parts of the dipeptide: Peptide Bond , N-Terminus and C-Terminus
c
• Protein sequences go from the N terminus, to the C terminus. The N terminus represents the
first amino group of the protein backbone, and the C terminus -------- represents the last
carboxylic acid group of the protein backbone.
N terminus, C terminus
N terminus, C terminus
N terminus, C terminus
N terminus, C terminus
Protein sequences are defined as amino to acid: from N terminus to C terminus. The N terminus is
called the <N= terminus because it refers to the first functional group in the chain, the amine which
contains a nitrogen atom. The final functional group is the C-terminus because it is the carboxylic
acid.
• Click and drag to match the structure to the description
LEVEL OF STRUCTURE, DESCRIPTION
PRIMARY sequence of amino acids held together by peptide bonds
, lOM oAR c P S D | 2527 011 4
SECONDARY the way that the local amino and carboxylic acid groups interact with each other in space
TERTIARY the overall, three-dimensional and completely folded structure
QUATERNARY the combination of two or more tertiary protein structures
QUATERNARY, SECONDARY, TERTIARY, PRIMARY
Primary structure – sequence of amino acids held together by peptide bonds.
Secondary structure – the way that the local amino and carboxylic acid groups interact with each
other in space
Tertiary structure – the overall, three-dimensional and completely folded structure
Quaternary structure – the combination of two or more tertiary protein structures
• What is the driving force for each level of structure?
Hydrophobic
H-bonding of the
Peptide bonds sidechain
backbone
interactions
Primary yes
Secondary yes
Tertiary yes
The primary structure is the sequence of amino acids, and is driven by the covalent peptide bonds
between amino acids in the polypeptide. The secondary structure is formed due to the backbone
Hydrogen bonding, specifically the carbonyl of the acid and the amine found in each amino acid.
The tertiary structure is primarily driven by the burying of hydrophobic sidechains, as they
rearrange to be away from surrounding water.
• Modeling Protein Structure with Wire
Complete the following activity and then answer the questions below about protein
structure.
Locate two long pieces of thin, bendable wire in your home (such as pipe cleaner,
garden wire, electrical wire, or similar), preferably 5-10 inches in length as well as a
pencil.
Straighten the wire and while grabbing each end, give it a good tug. This represents
CHEM 120 WEEK 7
• Select all that apply. Which of the following are typically solids at room temperature?
a. Polyunsaturated lipids
b. Trans lipids
c. Monounsaturated lipids
d. Saturated lipids
e. Unsaturated lipids
Both saturated fats and trans fats are solids at room temperature due to their linear structures.
• Which class of lipids is found in cell membranes?
a. Sterols
b. Triacylglycerol
c. Glycerolphospholipid
d. Steroids and Triacylglycerol
e. Steroids and Glycerolphospholipid
Glycerophospholipids make up the majority of the cell membrane, and sterols such as cholesterol
are also found in the membrane and used for stability.
• What type of linkage is found in triacylglycerols?
a. Glycoside
b. Ether
c. Amide
d. peptide
e. Ester
Tryiacylglycerols have ester linkages between the glycerol and fatty acids.
• Which of the following is true for both saturated and unsaturated fatty acids?
a. Both contain carboxylic acid groups
b. Both are solid at room temperature
c. Both are considered alkenes
d. Both are soluble in water
e. Both contain ester linkages
Both saturated and unsaturated fatty acids are monomers that contain a carbon chain and a
carboxylic acid group.
• Triacylglycerols contain .
a. 1 molecule of glycerol and 3 steroids
b. 3 molecules of glycerol and 1 molecule of fatty acid
c. 1 molecule of glycerol and 3 molecules of fatty acid
d. 3 molecules of glycerol and 1 steroid
Triacylglycerols are made of 1 molecule of glycerol and 3 fatty acids.
, lOM oAR c P S D | 2527 011 4
Proteins
• Rank the levels of protein structure from top (least complex/structured) to bottom (most
complex/structured).
a. Secondary – alpha helices, beta strands, and loops
b. Quaternary – interaction of multiple tertiary structures
c. Primary – sequence of amino acids
d. Tertiary – the three dimensional structure
The levels of protein structure in order of complexity are: primary, secondary, tertiary, and
quaternary.
• Examples of proteins include
a. meat and muscle
b. sugars and candy
c. butter and oil
d. all of these
Meat and muscle are example of proteins.
• Answer the following questions about the structure of amino acids.
Question
The backbone of an amino acid refers to all of the following except
a. the amine.
b. the carboxylic acid.
c. the sidechain.
d. the alpha carbon.
Question
Select all that apply. What functional groups are found in amino acids?
a. Alkene
b. Amine
c. Ester
d. Hydroxyl
e. Carboxylic acid
Question
Alpha carbons are always bound to
a. the amine.
b. a hydrogen.
c. the carboxylic acid.
d. the sidechain.
e. All of these.
Question 1 Feedback
The backbone is the portion of the amino acids that is consistent in each of the 20 amino acids. This
includes the amine, the alpha carbon, and the carboxylic acid. The sidechain will be different for
each amino acid, so that is not part of the backbone.
, lOM oAR c P S D | 2527 011 4
Question 2 Feedback
Amino acids all contain amine and carboxylic acid functional groups.
Question 3 Feedback
Alpha carbons are the center of the amino acid, bound to an H, the amine, the acid, and the
sidechain.
• Dipeptide
Locate these parts of the dipeptide: Peptide Bond , N-Terminus and C-Terminus
c
• Protein sequences go from the N terminus, to the C terminus. The N terminus represents the
first amino group of the protein backbone, and the C terminus -------- represents the last
carboxylic acid group of the protein backbone.
N terminus, C terminus
N terminus, C terminus
N terminus, C terminus
N terminus, C terminus
Protein sequences are defined as amino to acid: from N terminus to C terminus. The N terminus is
called the <N= terminus because it refers to the first functional group in the chain, the amine which
contains a nitrogen atom. The final functional group is the C-terminus because it is the carboxylic
acid.
• Click and drag to match the structure to the description
LEVEL OF STRUCTURE, DESCRIPTION
PRIMARY sequence of amino acids held together by peptide bonds
, lOM oAR c P S D | 2527 011 4
SECONDARY the way that the local amino and carboxylic acid groups interact with each other in space
TERTIARY the overall, three-dimensional and completely folded structure
QUATERNARY the combination of two or more tertiary protein structures
QUATERNARY, SECONDARY, TERTIARY, PRIMARY
Primary structure – sequence of amino acids held together by peptide bonds.
Secondary structure – the way that the local amino and carboxylic acid groups interact with each
other in space
Tertiary structure – the overall, three-dimensional and completely folded structure
Quaternary structure – the combination of two or more tertiary protein structures
• What is the driving force for each level of structure?
Hydrophobic
H-bonding of the
Peptide bonds sidechain
backbone
interactions
Primary yes
Secondary yes
Tertiary yes
The primary structure is the sequence of amino acids, and is driven by the covalent peptide bonds
between amino acids in the polypeptide. The secondary structure is formed due to the backbone
Hydrogen bonding, specifically the carbonyl of the acid and the amine found in each amino acid.
The tertiary structure is primarily driven by the burying of hydrophobic sidechains, as they
rearrange to be away from surrounding water.
• Modeling Protein Structure with Wire
Complete the following activity and then answer the questions below about protein
structure.
Locate two long pieces of thin, bendable wire in your home (such as pipe cleaner,
garden wire, electrical wire, or similar), preferably 5-10 inches in length as well as a
pencil.
Straighten the wire and while grabbing each end, give it a good tug. This represents
