CHEM 120 Week 7 LIPIDS Questions and Answers- Chamberlain College Atlanta
WEEK 7
Lipids
1. Which of the following is a source of lipids?
a. Water
b.
... [Show More] Sugar, fruits, and bread
c. Butter and oils
d. Steaks
Water is the by-product of condensation reactions.
Answer the following questions below about lipids.
Question 1 / 3
Triglycerides are:
a. used for catalysis in the body.
b. made of fatty acid monomers.
c. soluble in water.
d. always unsaturated.
Question 2 / 3
Select all that apply. Saturated fatty acids contain _____ functional groups.
a. amine
b. alkanes
c. alkenes
d. carboxylic acid
e. halogen
Question 3 / 3
From the condensed structural formula, determine if the structure represents a saturated fatty
acid, a monounsaturated fatty acid, or a polyunsaturated fatty acid.
SATURATED
FATTY ACID
MONOUNSATU
RATED FATTY
ACID
POLYUNSATUR
ATED FATTY
ACID
CH3CH2CHCHCH2
COOH yes
CH3CHCHCH2CH2
COOH yes
CH3CHCHCH2CH
CHCH2COOH yes
CH3CH2CH2CH2CH
2COOH yes
Question 1 Feedback
Triglycerides are made of fatty acid monomers.
Question 2 Feedback
Saturated fatty acids will contain all single bonds, thus contain alkanes, and will contain a
carboxylic acid functional group on one end.
Question 3 Feedback
Alkanes are saturated fatty acids and are represented by CH3 on the end carbon and CH2 for each
middle carbon. Monounsaturated fatty acids will contain a single double bond, represented by
CHCH in the condensed structural formula; polyunsaturated fatty acids will contain two or more
double bonds in the condensed structural formula.
2. Select the correct property for the category of fatty acids that it describes.
Contains carboxylic acid =
Saturated, Unsaturated, Both Saturated and Unsaturated
Contains a single double carbon-to-carbon bond =
Saturated, Unsaturated, Both Saturated and Unsaturated
Contains multiple double carbon-to-carbon bonds =
Saturated, Unsaturated, Both Saturated and Unsaturated
Solid at room temperature =
Saturated, Unsaturated, Both Saturated and Unsaturated
Contains no carbon-to-carbon double bonds =
Saturated, Unsaturated, Both Saturated and Unsaturated
Liquid at room temp =
Saturated, Unsaturated, Both Saturated and Unsaturated
Does not mix with water =
Saturated, Unsaturated, Both Saturated and Unsaturated
Both saturated and unsaturated do not mix with water.
Saturated contains no double carbon-to-carbon bonds and is solid at room temperature.
Unsaturated contains a single double carbon-to-carbon bond (monounsaturated) or multiple double
carbon-to-carbon bonds (polyunsaturated) and are mostly liquid at room temperature.
4. Using the molecule below, answer the following questions.
Question 1 / 3
Tis molecule is best described as
a. a fatty acid.
b. a triglyceride.
c. a polyunsaturated fatty acid.
d. an unsaturated fatty acid.
This image is a lipid, not a fatty acid. It is made from three fatty acids combined with a molecule of
glycerol, and is called a triglyceride or triacylglycerol.
Question 2 / 3
How many fatty acids were used to create this triacylglycerol molecule?
a. One
b. Two
c. Three
d. Four
Triacylglycerols are made from three fatty acids attached to one glycerol.
Question 3 / 3
The fatty acids used to create this triacylglycerol are
a. all identical.
b. all unsaturated.
c. all saturated.
d. all connected through an ester linkage.
All three fatty acids are connected to the glycerol through ester linkages. They are all different,
some being saturated and some unsaturated.
5. Click and drag the name of the lipid to match the function
Comprises the majority of cell membranes because it contains a polar head and a nonpolar tail. ---
glycerophospholipids
Used in soap making. --- triacylglycerol
Structure includes three six-member rings fused with a five-member ring, and in cell membranes provides
stability and is a precursor for vitamin D. --- cholesterol
cholesterol
glycerophospholipids
Triacylglycerol
Glycerophospholipids comprise the majority of cells due to their polar head and nonpolar tails,
allowing them to create a stable bi-layer structure.
Triacylglycerols are commonly used in soap making when combined with sodium hydroxide (lye).
The fused ring structure is cholesterol, one type of steroid.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
Proteins
11. 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.
12. 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.
13. Answer the following questions about the structure of amino acids.
Question 1 / 3
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 2 / 3
Select all that apply. What functional groups are found in amino acids?
a. Alkene
b. Amine
c. Ester
d. Hydroxyl
e. Carboxylic acid
Question 3 / 3
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.
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.
14. Dipeptide
Locate these parts of the dipeptide: Peptide Bond , N-Terminus and C-Terminus
c
15. 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.
16. Click and drag to match the structure to the description
LEVEL OF STRUCTURE, DESCRIPTION
PRIMARY sequence of amino acids held together by peptide bonds
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
17. What is the driving force for each level of structure?
Peptide bonds H-bonding of the
backbone
Hydrophobic
sidechain
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.
18. 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
the primary structure, held together with covalent bonds.
Next, twirl 2 inches of the wire around a pencil to make a spiral, leave a small gap of
1-2 inches of straight wire, then crinkle the next part two inches; the model should be
in a relatively straight line as you complete this process.
Repeat this pattern, or any pattern, for the remaining length of the wire. This
represents the secondary structure elements: alpha helix is the spiral, the loop is
unstructured, and the crinkles are the beta strands. This structure is held in place by
hydrogen bonds, intermolecular forces that are not as strong as covalent bonds.
Next, bend the structure at the loops to bury the hydrophobic sidechains and make a
3D structure. This represents the tertiary structure, in which hydrophobic sidechains
are buried, hydrophilic sidechains are left on the surface, and various other
intermolecular interactions occur to lock the 3D structure in place: disulfide bridges
form between two sulfur-containing sidechains; salt bridges form between cationic
and anionic sidechains, and hydrogen bonds between polar Hydrogen and nitrogen or
oxygen form. Some proteins will be fully functional at the tertiary structure, but we
will model the quaternary structure.
Finally, take the second wire and repeat the process. When you have your two
complete tertiary structures, place them near to each other to represent the quaternary
structure, which is made from two or more tertiary sequences.
Next, we will model denaturation. In this process, a protein will lose most of its
structure due to high salt, high temperature, a low pH, or a high pH. When a protein
loses its structure, it loses the ability to function.
Salt, temperature, and pH will cause the intermolecular forces to become interrupted.
Move the two protein chains apart to denature the quaternary structure. Pick up one
chain, and holding both ends as you did when starting the demo, pull the ends to
straighten the wire.
Question 1 / 5
What level of structure did the straightened wire represent throughout the
demonstration?
a. primary
b. secondary
c. tertiary
d. quaternary
Question 2 / 5
How did secondary structure differ from tertiary structure in this demo?
a. secondary structure was the straight wire, tertiary structure was the twists and
crinkles
a. secondary structure was when the straightened wire was twisted and
crinkled, tertiary was when the twists and crinkles were bent further to
make a 3D shape
b. secondary structure and tertiary structure were indistinguishable in this demo
c. secondary structure is the completed 3D protein chain, tertiary structure was
when the second chain was placed next to the first chain.
Question 3 / 5
After denaturation, what level of protein structure remained?
a. primary
b. secondary
c. tertiary
d. quaternary
Question 4 / 5
Select all that apply. What levels or protein structure were affected by
denaturation?
a. primary
b. secondary
c. tertiary
d. quaternary
Question 5 / 5
What causes denaturation? Select all that apply.
a. high pH
b. low pH
c. high salt
d. high temperature
Question 1 Feedback
The straightened wire represents the primary protein structure, or the sequence of amino acids
connected by strong covalent bonds.
Question 2 Feedback
Secondary structure was when the straightened wire was twisted around a pencil (alpha helix) and
crinkled (beta strands). The secondary structure was kept mostly in a line until ready to fold at the
loops to make the tertiary structure. The tertiary structure was when the twists and crinkles were
bent further to make a 3D shape.
Question 3 Feedback
After denaturation, the straight wire remained. This wire represents the primary structure of the
protein.
Question 4 Feedback
Denaturation was modeled by separating the two chains and pulling on the wire. The result was a
straight piece of wire (primary structure). This means that quaternary, tertiary, and secondary
structures were all affected by denaturation.
Question 5 Feedback
Denaturing of proteins is caused by high pH (basic), low pH (acidic), high salt, or high temperature.
19. Which level of protein structure is the three-dimensional shape?
a. Primary
b. Secondary
c. Tertiary
d. Quaternary
The 3D shape is the tertiary structure.
20. Which of the following is unique to each amino acid?
a. The amine
b. The alpha carbon
c. The carboxylic acid
d. The sidechain
There are 20 different sidechains on amino acids. They all contain amines, alpha carbons, and
carboxylic acids.
21. Identify the sidechain in the dipeptide.
A
B
C
D
The largest sidechain is the aromatic benzene ring on the C-terminal amino acid.
22. The primary structure of a protein is held together by
a. peptide bonds.
b. glycosidic bonds.
c. ester bonds.
d. All of these
The primary protein structure is the sequence of amino acids held together by amide, or peptide,
bonds.
23. What causes denaturation?
a. high pH
b. low pH
c. high salt
d. high temperature
e. all of the above
f. none of the above
Denaturation is caused by high pH, low pH, high salt, or high temperature.
24. Which level of protein structure is the interaction of multiple protein chains?
a. primary
b. secondary
c. tertiary
d. quaternary
The interaction of multiple protein chains is the quaternary structure.
25. Select all that apply. What is the result when a protein is denatured?
a. the primary structure is altered
b. the secondary structure is altered
c. the tertiary structure is altered
d. the quaternary structure is altered
e. all four levels of protein structure are altered
f. it can no longer function
When a protein is denatured, it can no longer function because its secondary, tertiary, and
quaternary structures have been altered.
Enzymes
26. Which of the following macromolecules best describes enzymes?
a. proteins
b. carbohydrates
c. nucleic acids
d. lipids
27. Enzymes are a type of protein that functions in performing chemical reactions quickly
(catalysis).
When an enzyme is denatured, this will affect both its structure and its function.
a. True
b. False, this will not affect its structure.
c. False, this will not affect its function.
d. False, this will not affect either structure or function.
When an enzyme is denatured, its structure falls apart. An incorrectly folded structure will affect
the enzyme’s ability to function. This statement is therefore true.
28. Answer the questions below about the structure and role of enzymes.
Question 1 / 3
An Enzyme is a type of protein that performs chemical reactions quickly without being consumed,
also called a Catalyst. To start the reaction, the enzyme must bind the Substrate molecule in its
Active site, a specific location in the enzyme where the chemical reaction will occur. When the
chemical reaction is complete, the Substrate is released and the enzyme can start the process again.
Enzyme, Substrate, Active site, Catalyst, Active site
Drag and drop the correct answers into the boxes. You can also click the correct answer, then the
box where it should go. Reset my answers.
Question 2 / 3
True or false. Enzymes bind a single substrate or class of substrates.
a. True
b. False
Question 3 / 3
Which part of the enzyme allows substrate specificity?
a. active site
b. Protein
c. allosteric site
d. reaction site
Question 1 Feedback
An enzyme is a type of protein that performs chemical reactions quickly without being consumed,
also called a catalyst. To start the reaction, the enzyme must bind the substrate molecule in its
active site, a specific location where the chemical reaction will occur. When the chemical reaction is
complete, the product is released and the enzyme can start the process again
Question 2 Feedback
Because of the specific shape and polarity of the active site, only one substrate or extremely similar
types of substrates will be able to bind for catalysis.
Question 3 Feedback
The active site is a specific size and polarity, allowing only specific substrates to bind.
29. Answer the questions below about factors that affect enzyme activity.
Question 1 / 4
Which of the following affects an enzyme’s ability to function?
a. High pH
b. Low pH
c. Cofactors
d. Inhibitors
e. All of these above affect an enzyme’s ability to function
Question 2 / 4
A molecule that mimics the substrate in size and polarity binds the active site, preventing the true
substrate from being catalyzed. This is an example of
a. a coenzyme.
b. noncompetitive inhibition.
c. Denaturing.
d. competitive inhibition.
e. a cofactor.
Question 3 / 4
A molecule binds an allosteric site on the enzyme away from the active site, which causes the
enzyme’s active site to change shape. This is an example of
a. a cofactor.
b. competitive inhibition.
c. Denaturing.
d. a coenzyme.
e. noncompetitive inhibition.
Question 4 / 4
There are several ways that enzyme structure and function are affected. Mark whether the example
will affect the protein’s tertiary structure and overall folding, or if it will not affect the protein’s
structure.
Affects enzyme’s tertiary
structure
Does not affect enzyme’s
tertiary structure
Coenzymes yes
Competitive inhibition yes
Noncompetitive inhibition yes
Denaturing yes
Question 1 Feedback
Temperature, pH, and salt will denature the enzyme; cofactors and coenzymes are required for a
functioning holoenzyme; inhibitors negatively affect an enzyme’s ability to bind a substrate in the
active site.
Question 2 Feedback
Competitive inhibition involves a molecule similar to the substrate competing for the active site and
binding there, blocking the true substrate.
Question 3 Feedback
Noncompetitive inhibition will have a molecule binding to an allosteric site, and as a result the
active site will change shape.
Question 4 Feedback
Competitive inhibition does not affect an enzyme’s overall structure, and is easily reversible.
30. Answer the questions below about enzymes.
Question 1 / 3
When __________, inorganic ions required for the complete structure of the enzyme, are not
incorporated into the enzyme structure, the remaining protein-only portion is called ______.
a. coenzyme / holoenzyme
b. cofactor / holoenzyme
c. coenzyme / apoenzyme
d. cofactor / apoenzyme
The apoenzyme is the protein-only portion of a holoenzyme, and is not functional without its
cofactors/coenzymes.
Answer the questions below about enzymes.
Question 2 / 3
Determine if the example would act as a coenzyme or a cofactor in a holoenzyme.
Coenzyme Cofactor
Vitamin B12 yes
Iron yes
Niacin yes
Magnesium yes
Calcium yes
Example Coenzyme Cofactor
Vitamin B12 x
Iron x
Niacin x
Magnesium x
Calcium x
Answer the questions below about enzymes.
Question 3 / 3
Which of the following is an example of a typical enzyme function?
a. Catabolizing nutrients into monomer building blocks
b. Anabolizing glycogen
c. Catalyzing the construction of DNA
d. All of these
e. None of these
Enzymes play a role in catabolism as well as anabolism (polymerization).
31. Drag and drop the term to the correct description.
Term, Description
allosteric site ------- Location where a noncompetitive inhibitor will bind
active site ------------ Location where a competitive inhibitor will bind
allosteric site, apoenzyme, holoenzyme, active site
The allosteric site is where a noncompetitive inhibitor will bind. The active site is where the
competitive inhibitor will bind, because it is similar in shape and polarity to the true
substrate.
32. How many substrates does an enzyme typically have?
a. One, or one group of similar substrates
b. Two, or two groups of similar substrates
c. It varies, but typically one for each quaternary structure
d. Many: there is no limit
An enzyme typically has one substrate, or a group of extremely similar substrates. This is
due to the specificity of the active site, which can accommodate only certain sizes and
polarities.
33. Which of the following is incorrectly matched?
a. activation energy – location where the substrate will bind and the reaction will occur
b. denature – to cause a protein to lose its secondary, tertiary, and quaternary structures
c. noncompetitive inhibitor – binds the allosteric site to alter the shape of the active site
d. cofactor – inorganic ion required for holoenzyme function
e. catalyst - increases the speed of a reaction without being consumed
Thea active site is the location where the substrate will bind and the reaction will occur.
34. C oenzyme are organic vitamins required for the complete structure of the enzyme,
called holoenzyme.
Cofactor, apoenzyme, coenzyme, holoenzyme
Cofactor, apoenzyme, coenzyme, holoenzyme
Coenzymes are the organic vitamins required to complete the structure of the holoenzyme.
35. Which of the following is a possible role of enzymes?
a. Performs structural role in cell walls and catabolic reactions
b. Performs catabolic and anabolic reactions
c. Performs a structural role in cell walls
d. Performs anabolic reactions
e. Performs catabolic reactions
Enzymes perform catabolic and anabolic reactions
36. Enzymes decrease
a. the activation energy of a reaction.
b. the total number of reactions.
c. the speed of a reaction.
d. the number of products in a reaction.
Enzymes decrease the activation energy of a reaction, thereby increasing the speed, total
number of reactions, and the number of products.
Nucleic Acids
37. What are the monomers of nucleic acids?
a. amino acids
b. Monosaccharides
c. Nucleotides
d. fatty acids
Nucleotides are the monomers that make up nucleic acid polymers.
38. Which of the following is an example of a nucleic acid? Select all that apply.
a. Carbohydrate
b. Lipids
c. Proteins
d. DNA
e. RNA
DNA and RNA are examples of nucleic acids
39. Sort the nucleotides to correctly categorize as purines or pyrimadines.
Purines Pyrimadines
Nucleotides Adenine, Guanine Cytosine, Thymine, Uracil
Adenine, Cytosine, Guanine, Thymine, Uracil
Purines include adenine and guanine. Pyrimidines include cytosine, thymine, and uracil.
40. Identify the sugar, phosphate, and base in the image of the nucleotide.
Phosphate, nitrogen base sugar, 1
Phosphate, nitrogen base, sugar, 2
Phosphate, nitrogen base, sugar, 3
41. Answer the following questions about nucleic acids.
Question 1 / 5
________ are the monomers of nucleic acids.
a. Amino acids
b. Monosaccharides
c. Nucleotides
d. Fatty acids
Question 2 / 5
Select all that apply. The backbone of a nucleic acid includes:
a. hydrogen bonds
b. nitrogen base
c. carboxylic acid
d. Sugar
e. phosphate
Question 3 / 5
Which portion of a nucleotide creates the primary structure of a nucleotide?
a. Deoxyribose sugar
b. Ribose sugar
c. Diester bonds
d. Nitrogen base
e. Phosphate
Question 4 / 5
Which type of bonding is found in nucleic acid backbones?
a. Acid anhydride bonds
b. Phosphodiester bonds
c. Hydrogen bonds
d. Glycosidic bonds
Question 5 / 5
Click the box to indicate that the description is correct for DNA, RNA, or both.
DNA RNA
Contains a single strand yes
Contains deoxyribose
sugar
yes
Contains uracil nucleotide yes
Contains adenine
nucleotide yes yes
Hydrogen bonds between
nucleotides on opposite
strands stabilize its
structure
yes
Question 1 Feedback
Nucleotides are the monomers of nucleic acids.
Question 2 Feedback
Sugars and phosphates connected by phosphodiester bonds create the backbone of nucleic acids.
Question 3 Feedback
The sequence is the order of the nitrogen bases.
Question 4 Feedback
Phosphodiester bonds join nucleotides in the nucleic acid polymer: the phosphate forms ester bonds
to two sugars in the structure.
Question 5 Feedback
DESCRIPTION DNA RNA
Contains a single strand X
Contains deoxyribose
sugar
X
Contains uracil
nucleotide
X
Contains adenine
nucleotide
X X
Hydrogen bonds
between nucleotides on
opposite strands stabilize
its structure
X
42. Click the boxes to determine if the nitrogenous base is present in DNA, RNA, or both.
DNA RNA
Adenine yes yes
Cytosine yes yes
Guanine yes yes
Thymine yes
Uracil yes
Nucleotide DNA RNA
Adenine x x
Cytosine x x
Guanine x x
Thymine x
Uracil x
43. Sugar Molecule
Click the location of on the sugar molecule that determines if this is deoxyribose or ribose.
The 2’ –OH on the second carbon from the nitrogen base is the location of the hydroxyl (alcohol)
group that determines if the sugar is ribose or deoxyribose.
Structural differences give different functions to DNA and RNA. The large and bulky DNA
holds the entire genetic code, or the DNA sequence, of the organism. This molecule does not
move around the cell because it is large and bulky. The smaller, single stranded RNA
molecules hold information from part of the genetic code. RNAs have the ability to travel in
the cell and perform different functions due to their structure. Both of these molecules are
used to create proteins in the cell.
There are three types of RNA, each with a unique function:
Messenger RNA (mRNA) – copies the information encoded in the DNA and carries it to
the site of protein synthesis called the ribosome
Transfer RNA (tRNA) – carries an individual amino acid to the ribosome, where it pairs
with the mRNA
Ribosomal RNA (rRNA) – one structural component of the ribosome
44. Drag the label to the correct location on the image below
rRNA is used to build the ribosome. The mRNA carries the message to the ribosome and is
represented by the RNA strand inside the ribosome. The tRNA carries the amino acid and is shaped
like a letter “t”.
45. Match the nucleic acid with its function.
Stays in one location in the cell and holds all genetic information --- DNA
Carries a part of the genetic information to the ribosome --- mRNA
Makes up the ribosome --- rRNA
Carries amino acids to the ribosome --- tRNA
TRNA, rRNA, mRNA, DNA
rRNA is used to build the ribosome. The mRNA carries the message from the DNA to the ribosome.
The tRNA carries the amino acid to the ribosome. The DNA is the entire genetic code of the
organism.
46. Answer the following questions relating to DNA and RNA.
Question 1 / 2
Which is the best description of the function of DNA?
a. It carries the amino acid to the ribosome
b. It builds the ribosome
c. It carries part of the DNA genetic information to the ribosome
d. It holds the entire genetic code
Question 2 / 2
47. Both DNA and RNA…
a. are nucleic acids and information molecules
b. move to different parts of the cell
c. are nucleic acids, information molecules, and move to different parts of the cell
d. are information molecules
e. are nucleic acids
Question 1 Feedback
The DNA holds the entire genetic code and does not move within the cell.
Question 2 Feedback
Both DNA and RNA are nucleic acids, and both are information molecules. Only RNA moves in the
cell, due to its smaller structure.
48. Which is the best description of the function of tRNA?
a. It carries the amino acid to the ribosome
b. It holds the entire genetic code
c. It builds the ribosome
d. It carries part of the DNA genetic information to the ribosome
tRNA carries the amino acid to the ribosome.
49. A purine base will pair with a pyrimidine base.
Purine, lysine, guanine
Pyrimid, pyrimidine, perimeter
A purine base will pair with a pyrimidine base
50. Match the structural description to DNA or RNA.
DNA --- Double stranded, Deoxyribose sugar, ACGT bases
RNA --- Single stranded, ACGU bases, Ribose sugar
ACGT bases, Single stranded, Deoxyribose sugar, ACGU bases, Ribose sugar, Double stranded
Both DNA and RNA are nucleic acids with different structures. The main structural
differences between DNA and RNA are that DNA has two strands but RNA is single
stranded; DNA contains deoxyribose sugar, and RNA contains ribose sugar; DNA contains
A, C, G and T nitrogen bases in its nucleotides, but RNA contains A, C, G and U nitrogen
bases.
51. A nucleotide contains ribose sugar. This nucleotide would likely be found in the polymer
a. Glycogen
b. Ribosome
c. RNA
d. DNA
This nucleotide would likely be found in the polymer RNA.
52. Where is rRNA found in the image below?
a. In the blue mRNA strip.
b. Outside the ribosome.
c. In the lime green ribosome constucted of large and small subunits.
d. In the colored columns along the blue mRNA strip.
rRNA is the ribosomal RNA that makes up part of the ribosome structure. The ribosome is
used to make a protein.
53. Select all that apply. Which of the following are purine bases?
a. Cytosine
b. Thymine
c. Adenine
d. Guanine
e. Uracil
Purines include adenine and guanine, and contain two rings in their nitrogen bases.
54. The general structure of a nucleotide includes
a. sugar and nitrogen base
b. nitrogen base
c. sugar, phosphate, nitrogen base
d. phosphate and nitrogen base
e. sugar and phosphate
A nucleotide contains a sugar, phosphate, and nitrogen containing base.
Flow of Genetic Information
55. The monomer of proteins is the _________.
a. Monosaccharide
b. fatty acid
c. nucleic acid
d. amino acid
Amino acids are the monomers of proteins.
56. Match the RNA with its function.
moves amino acid to the ribosome --- tRNA
makes up the ribosome --- rRNA
moves genetic information from DNA to ribosome --- mRNA
RRNA, tRNA, mRNA
moves amino acid to the ribosome – tRNA
makes up the ribosome – rRNA
moves genetic information from DNA to ribosome – mRNA
57. Answer the following questions to check your knowledge on DNA replication.
Question 1 / 4
In DNA replication, each new DNA molecule is
a. Unique
b. transformed into RNA
c. made of one parent and one daughter strand
d. all of the above
Question 2 / 4
Which enzyme functions to make the new DNA strand through complementary base
pairing with the original strand?
a. RNA polymerase
b. Helicase
c. DNA polymerase
d. ribosome
Question 3 / 4
Place the steps of DNA replication in the correct order from top to bottom.
Helicase enzyme unwinds DNA strands
DNA polymerase enzyme copies the DNA strand
The two new DNA molecules contain one original and one new DNA strand
Question 4 / 4
Determine the sequence of the new DNA strand.
Orgin
inal
DNA: T C G C G T T C A
New
DNA:
A G C G C A A G T
Question 1 Feedback
In DNA replication, the new DNA molecules each contain one new strand (the daughter
strand) and one original strand (parent strand). These strands will be identical to the
original, and remain DNA.
Question 2 Feedback
DNA polymerase is the enzyme that makes a DNA polymer in replication.
Question 3 Feedback
In DNA replication, first the helicase enzyme unwinds the double stranded DNA to expose
the nucleotides. Then, DNA polymerase makes a copy through complementary base
pairing. When DNA polymerase is complete, the two newly formed DNA molecules contain
one original and one new strand of nucleotides.
Question 4 Feedback
In DNA, T will pair with A, C will pair with G, G will pair with C, and A will pair with T.
Following these rules, the new strand would be A-G-C-G-C-A-A-G-T
58. Answer the following questions to check your knowledge on transcription.
Question 1 / 2
Determine the sequence of the mRNA strand.
Orgin
inal
DNA: T C G C G T T C A
mRN
A
A
G
A
G
A
G
A
G
A
G
A
G
A
G
A
G
A
G
C
U
C
U
C
U
C
U
C
U
C
U
C
U
C
U
C
U
Question 2 / 2
Which enzyme is responsible for the unwinding the DNA double helix in transcription?
a. DNA polymerase
b. Ribosomes
c. Helicase
d. RNA polymerase
Question 1 Feedback
In transcription, the T will pair with A, C will pair with G, G will pair with C, and A will
pair with U instead of T. Following these rules, the resulting mRNA sequence would be AG-C-G-C-A-A-G-U.
Question 2 Feedback
As in DNA replication, the helicase enzyme will unwind the DNA helix.
59. Click and drag to label the processes shown in this figure of gene expression
(central dogma)
Replication, Transcription, Translation
Transcription, Translation, Replication
DNA replication is the first process shown, where DNA is copied. Transcription is the
process where DNA code is paired to make an RNA code. The final step is translation,
where the RNA code is read to create the protein.
60. Place the steps of translation in order from top to bottom.
a. The ribosome disassembles, releasing mRNA, tRNA, and the polypeptide chain.
b. The ribosome moves to the next codon, releasing the empty tRNA.
c. Ribosome assembles around mRNA and tRNA.
d. The amino acid is transferred onto the growing polypeptide chain.
e. Elongation continues until the ribosome reaches a stop codon.
f. A new tRNA enters the ribosome.
Ribosome assembles around mRNA and tRNA.
A new tRNA enters the ribosome.
The amino acid is transferred onto the growing polypeptide chain.
The ribosome moves to the next codon, releasing the empty tRNA.
Elongation continues until the ribosome reaches a stop codon.
The ribosome disassembles, releasing mRNA, tRNA, and the polypeptide chain.
Click and drag the enzymes to the correct portion of the paragraph.
61. The DNA polymerase copies DNA in replication. The RNA polymerase
uses DNA to make mRNA in transcription. The ribosome is the site of protein synthesis.
Ribosome, RNA polymerase, DNA polymerase
Most of the enzymes are named for what they do or their product. The enzyme DNA
polymerase copies DNA, and creates two new DNA molecules identical to the original. The
RNA polymerase uses DNA to make an mRNA molecule in transcription. The ribosome is
the site of protein synthesis, and the polymerase responsible for making proteins.
62. Match the description to the process.
This process uses mRNA to create a polypeptide --- Translation
This process uses DNA to make mRNA --- Transcription
This process uses DNA to make DNA --- Replication
Transcription, Replication, Translation
This process uses mRNA to create a polypeptide – Translation
This process uses DNA to make mRNA – Transcription
This process uses DNA to make DNA – Replication
63. Answer the following questions using the codon table below.
Second Base
First
Base
U C A G Third
Base
U
UUU →
Phe
UUC →
Phe
UCU →
Ser
UCC →
Ser
UAU →
Tyr
UAC →
Tyr
UGU → Cys
UGC → Cys
UGA →
STOP
UUA →
Leu
UUG →
Leu
UCA →
Ser
UCG →
Ser
UAA →
STOP
UAG →
STOP
UGG → Trp
C
CUU →
Leu
CUC →
Leu
CUA →
Leu
CUG →
Leu
CCU →
Pro
CCC →
Pro
CCA →
Pro
CCG →
Pro
CAU →
His
CAC →
His
CAA →
Gln
CAG →
Gln
CGU → Arg
CGC → Arg
CGA → Arg
CGG → Arg
A
AUU → lle
AUC → lle
AUA → lle
AUG →
MET
ACU →
Thr
ACC →
Thr
ACA →
Thr
ACG →
Thr
AAU →
Asn
AAC →
Asn
AAA →
Lys
AAG →
Lys
AGU → Ser
AGC → Ser
AGA → Arg
AGG → Arg
G
GUU → Val
GUC → Val
GUA → Val
GUG → Val
GCU →
Ala
GCC →
Ala
GCA →
Ala
GCG →
Ala
GAU →
Asp
GAC →
Asp
GAA →
Glu
GAG →
Glu
GGU → Gly
GGC → Gly
GGA → Gly
GGG → Gly
Question 1 / 6
What is the amino acid encoded by the mRNA codon UAC?
a. Met
b. Val
c. Tyr
d. His
Using the codon table, the first letter is U, second is A, and third is C. On the codon table,
UAC is the amino acid Tyr.
Question 2 / 6
What is the amino acid encoded by the mRNA codon AUU?
a. Leu
b. Ile
c. Stop
d. Asn
Using the codon table, the first letter is A, second is U, and third is U. On the codon table,
AUU is the amino acid Ile
Question 3 / 6
What is the dipeptide encoded by the mRNA sequence UACAUU?
a. Ile-Tyr
b. Tyr-Ile
c. Val – Asn
d. both a and b are correct
First we separate the codons in the mRNA sequence into UAC | AUU. Using the codon
table, the first codon is Tyr and the second is Ile. The resulting dipeptide is Tyr-Ile.
Question 4 / 6
What is the dipeptide encoded by the DNA sequence ATGACC?
a. Gly - Asp
b. Ile - Thr
c. Tyr-Trp
d. Pro - Leu
This is an example of gene expression. First, the DNA sequence is transcribed to mRNA
through base pairing: ATGACC will pair with UACUGG in the mRNA. The mRNA is then
separated into codons UAC and UGG, and translated into Tyr-Trp.
Question 5 / 6
Which best describes gene expression?
a. the translation of mRNA to form a protein
b. the transcription and translation of a region of DNA to form a protein
c. the transcription of DNA to form mRNA
d. the replication of DNA
Gene expression is the process of transcription and translation of a region of DNA to form a
protein. The encoding region of the DNA is the gene, and when it is expressed it forms a
protein.
Question 6 / 6
Degeneracy…
a. allows multiple amino acids to be encoded by the same codon
b. allows a single amino acid to be encoded by multiple codons
c. allows a large variety of amino acids to be encoded by four nucleotide bases
d. all of the above
Degeneracy is the idea that there can be some variation in codon, and it will not change the
protein structure. This means that multiple codons will encode the same amino acid.
64. Complete the gene expression for the following DNA sequence:
Origi
nal
DNA: A G T C A C G T A
mRN
A:
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G
Protei
n:
Ser Val His
In transcription, the T will pair with A, C will pair with G, G will pair with C, and A will
pair with U instead of T. Following these rules, the resulting mRNA sequence would be u-ca-g-u-g-c-a-u. This gives the codons UCA – GUG – CAU encoding Ser-Val-His, respectively.
65. Codons show ______, because multiple codons code for the same amino acid.
a. Replication
b. Consistency
c. Structure
d. degeneracy
The concept of degeneracy allows for small variations in the genetic code at the codon level
without altering the protein structure. This means that multiple codons can be used to
encode the same amino acid.
66. Which process of gene expression uses mRNA as a template to produce a protein?
a. Translation
b. Transcription
c. Replication
d. transformation
In translation, the language of the nucleic acids is changed to that of amino acids and
polypeptides.
67. The final product of gene expression is
a. DNA
b. all RNAs
c. MRNA
d. protein
Gene expression uses DNA to produce proteins. The protein would be final product, the end
result.
68. Determine the sequence of the mRNA strand.
Orgin
inal
DNA: T A C T G G C A T
mRN
A
A
C
G
U
A
C
G
U
A
C
G
U
A
C
G
U
A
C
G
U
A
C
G
U
A
C
G
U
A
C
G
U
A
C
G
U
In transcription, the T will pair with A, C will pair with G, G will pair with C, and A will
pair with U instead of T. Following these rules, the resulting mRNA sequence would be AU-G-A-C-C-G-U-A
69. Complete the gene expression for the following DNA sequence. The codon
table is provided below.
Origi
nal
DNA: A G T C A C G T A
mRN
A
G
A
U
C
G
A
U
C
G
A
U
C
G
A
U
C
G
A
U
C
G
A
U
C
G
A
U
C
G
A
U
C
G
A
U
C
protei
n
Val
Ser
His
Val
Ser
His
Val
Ser
His
Second Base
First
Base
U C A G Third
Base
U
UUU →
Phe
UUC →
Phe
UUA →
Leu
UUG →
Leu
UCU →
Ser
UCC →
Ser
UCA →
Ser
UCG →
Ser
UAU →
Tyr
UAC →
Tyr
UAA →
STOP
UAG →
STOP
UGU → Cys
UGC → Cys
UGA →
STOP
UGG → Trp
C
CUU →
Leu
CUC →
CCU →
Pro
CCC →
CAU →
His
CAC →
CGU → Arg
CGC → Arg
CGA → Arg
Leu
CUA →
Leu
CUG →
Leu
Pro
CCA →
Pro
CCG →
Pro
His
CAA →
Gln
CAG →
Gln
CGG → Arg
A
AUU → lle
AUC → lle
AUA → lle
AUG →
MET
ACU →
Thr
ACC →
Thr
ACA →
Thr
ACG →
Thr
AAU →
Asn
AAC →
Asn
AAA →
Lys
AAG →
Lys
AGU → Ser
AGC → Ser
AGA → Arg
AGG → Arg
G
GUU → Val
GUC → Val
GUA → Val
GUG → Val
GCU →
Ala
GCC →
Ala
GCA →
Ala
GCG →
Ala
GAU →
Asp
GAC →
Asp
GAA →
Glu
GAG →
Glu
GGU → Gly
GGC → Gly
GGA → Gly
GGG → Gly
In transcription, the T will pair with A, C will pair with G, G will pair with C, and A will
pair with U instead of T. Following these rules, the resulting mRNA sequence would be u-ca-g-u-g-c-a-u. This gives the codons UCA – GUG – CAU encoding Ser-Val-His, respectively.
70. What is the amino acid encoded by the mRNA codon CCA?
a. Pro
b. Gly
c. Thr
d. Trp
The mRNA codon CCA has C in the first position, C in the second position, and
U in the third position. This encodes the amino acid Pro (proline). [Show Less]