Concept explainers
Videos
The following is a portion of a protein: met-trp-tyr-arg-gly-pro-thr-Various mutant forms of this protein have been recovered. Using the normal and mutant sequences, determine the DNA and mRNA sequences that code for this portion of the protein, and explain each of the mutations.
- a. met-trp-
- b. met-cys-ile-val-val-leu-gln-
- c. met-trp-tyr-arg-ser-pro-thr-
- d. met-trp-tyr-arg-gly-ala-val-ile-ser-pro-thr-
a.
To determine: The DNA and mRNA sequences that code for this normal protein “met-trp-tyr-arg-gly-pro-thr” and explain the mutation in “met-trp”.
Introduction: The proteins are coded from triplet codons. There are 64 triplet codons, which code for 20 amino acids in which initiation and stop codons are also included. The initiation codons allow the mRNA to transcribe the DNA template while stop codons restrict the translation.
Explanation of Solution
The possible triplet codons for the normal protein “met-trp-tyr-arg-gly-pro-thr” are as follows:
| Met | Trp | Tyr | Arg | Gly | Pro | Thr |
| AUG | UGG | UAU | AGA | GGU | CCU | ACU |
| UAC | AGG | GGC | CCC | ACC | ||
| GGA | CCA | ACA | ||||
| GGG | CCG | ACG |
These are the possible triplet codons for “met-trp-tyr-arg-gly-pro-thr” protein. Any mutation in the above sequences may lead to mutation.
The first mutation occurred and formed “met-trp” protein. Possibly, the mutation occurred at ‘tyr’, which resulted in the termination. The termination is caused by a stop codon. The possible triplet codons after mutation in “met-trp” are :
| Met | Trp | Stop codons |
| AUG | UGG | UAA |
| UAG |
In the original sequence, tyrosine is present. However in mutated sequences, stop codons are formed, which shorten the polypeptide to Trp.
b.
To determine: The DNA and mRNA sequences that code for this normal protein “met-trp-tyr-arg-gly-pro-thr” and explain the mutation in “met-cys-ile-val-val-leu-gln”.
Introduction: The proteins are coded from triplet codons. There are 64 triplet codons which code for 20 amino acids in which initiation and stop codons are also included. The initiation codon allows the mRNA to transcribe the DNA template; whereas, stop codons restrict the translation.
Explanation of Solution
The possible triplet codons for the normal protein “met-trp-tyr-arg-gly-pro-thr” are as follows:
| Met | Trp | Tyr | Arg | Gly | Pro | Thr |
| AUG | UGG | UAU | AGA | GGU | CCU | ACU |
| UAC | AGG | GGC | CCC | ACC | ||
| GGA | CCA | ACA | ||||
| GGG | CCG | ACG |
These are the possible triplet codons for “met-trp-tyr-arg-gly-pro-thr” protein. Any mutation in the above sequences may lead to mutation.
The second mutation occurred and formed “met-cys-ile-val-val-leu-gln” protein. Possibly the point mutation occurred which caused changes in the reading frame. The triplet codons of the mutated protein “met-cys-ile-val-val-leu-gln” are :
| Met | Cys | Ile | Val | Val | Leu | Gln |
| AUG | UGU | AUA | GUG | GUC | CUA | ACU |
| GUG | ACC | |||||
| ACA | ||||||
| ACG |
The highlighted codons are mutated. The single place deletion or insertion may arise this type of situation where the complete sequence is changed.
c.
To determine: The DNA and mRNA sequences that code for this normal protein “met-trp-tyr-arg-gly-pro-thr” and explain the mutation in “met-trp-tyr-arg-ser-pro-thr”.
Introduction: The proteins are coded from triplet codons. There are 64 triplet codons which code for 20 amino acids in which initiation and stop codons are also included. The initiation codon allows the mRNA to transcribe the DNA template; whereas, the stop codons restrict the translation.
Explanation of Solution
The possible triplet codons for the normal protein “met-trp-tyr-arg-gly-pro-thr” are as follows:
| Met | Trp | Tyr | Arg | Gly | Pro | Thr |
| AUG | UGG | UAU | AGA | GGU | CCU | ACU |
| UAC | AGG | GGC | CCC | ACC | ||
| GGA | CCA | ACA | ||||
| GGG | CCG | ACG |
These are the possible triplet codons for “met-trp-tyr-arg-gly-pro-thr” protein. Any mutation in the above sequences may lead to mutation.
The third mutation occurred and formed “met-trp-tyr-arg-ser-pro-thr” protein. Possibly the frameshift mutation occurred, which caused changes in the reading frame. The triplet codons of the mutated protein “met-trp-tyr-arg-ser-pro-thr” are :
| Met | Trp | Tyr | Arg | Ser | Pro | Thr |
| AUG | UGG | UAU | AGA | AGU | CCU | ACU |
| UAC | AGG | CCC | ACC | |||
| CCA | ACA | |||||
| CCG | ACG |
Here, the only codon for glycine is completely changed. The single frame is inserted and deleted from the same place.
d.
To determine: The DNA and mRNA sequences that code for this normal protein “met-trp-tyr-arg-gly-pro-thr” and explain the mutation in “met-trp-tyr-arg-gly-ala-val-ile-ser-pro-thr-”.
Introduction: The proteins are coded from triplet codons. There are 64 triplet codons, which code for 20 amino acids in which initiation and stop codons are also included. The initiation codon allows the mRNA to transcribe the DNA template; whereas, the stop codons restrict the translation.
Explanation of Solution
The possible triplet codons for the normal protein “met-trp-tyr-arg-gly-pro-thr” are as follows:
| Met | Trp | Tyr | Arg | Gly | Pro | Thr |
| AUG | UGG | UAU | AGA | GGU | CCU | ACU |
| UAC | AGG | GGC | CCC | ACC | ||
| GGA | CCA | ACA | ||||
| GGG | CCG | ACG |
These are the possible triplet codons for “met-trp-tyr-arg-gly-pro-thr” protein. Any mutation in the above sequences may lead to mutation.
The second mutation occurred and formed “met-trp-tyr-arg-gly-ala-val-ile-ser-pro-thr-” this protein. This is a type of mutation where the reading frame is shifted because this protein is relatively larger than the normal protein.
Hence, frame insertion is a possible way due to which the protein is completely changed.
Want to see more full solutions like this?
Chapter 9 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
- In Drosophila, an X linked recessive mutation, scalloped (sd), causes irregular wing margins. Diagram the F1 and F2 results if a (a) scalloped female is crossed with a normal male; (b) a scalloped male is crossed with a normal female (assume the female is homozygous). Compare these results to what you would find if the trait was not sex linked.arrow_forwardCase Study—Ella Ella has a family history of diabetes. She wants to follow a healthful eating pattern that can lower her risk for developing this condition. Her dietitian recommends a goal of 450 to 600 kcal per meal and advises Ella to follow the Acceptable Macronutrient Distribution Range (AMDR) for carbohydrates and the Dietary Guidelines for Americans 2015-2020, which recommend limiting added sugar. She also recommends that Ella choose whole grains rather than processed grains. Ella decides to pack a lunch to take to work every day. This morning she’s making a sandwich for her lunch. Categories of Sandwich Options (Top of the screen) Breads Spreads Cheeses Vegetables Proteins Specific food items to select White Bread 6-inches Honey Mustard Provolone LettuceTomatoBell Peppers Turkey Part A - Reading Nutrition Facts Panels for Total Kilocalories How many total kilocalories are in Ella’s sandwich exactl ______kcal ? Part B - Reading Nutrition Facts Panels for…arrow_forwardC MasteringHealth MasteringNu × session.healthandnutrition-mastering.pearson.com/myct/itemView?assignment ProblemID=17465255&attemptNo=1&offset=prevarrow_forwardBiopharmaceutics and Pharmacokinetics:Two-Compartment Model Instant Absorption Questions SHOW ALL WORK, including equation used, variables used and each step to your solution, report your regression lines and axes names (with units if appropriate) :Calculate a-q a) B1, b) B2, c) hybrid rate constant (1) d) hybrid rate constant (2) e) t1/2,dist f) t1/2,elim g) k10 h) k12 i) k21 j) initial concentration (C0) k) central compartment volume (V1) l) steady-state volume (Vss) m) clearance (CL) AUC (0→10 min) using trapezoidal rule n) AUC (20→30 min) using trapezoidal rule o) AUCtail (AUC360→∞) p) total AUC (using short cut method) q) volume from AUC (VAUC)arrow_forwardGlitazones reduce insulin resistance by binding to a transcription factor in adipocytes, thereby reducing thesecretion of fatty acids. Glitazones are taken orally (in pill form). Using pharmacokinetic modeling, deriveequations to describe how the concentration of glitazones varies in the plasma as a function of time. Yourequations should be of the form: dCglitazone /dt = something, or dMglitazone /dt = something. Your model shouldinclude three compartments: the gut, the plasma, and the fatty tissues. Make sure to include a diagram thatillustrates your thinking, state all assumptions, and define your variables. Do not solve the equations.arrow_forwardCase Study—Ella Review the case study and then answer Parts A through F. Ella has a family history of diabetes. She wants to follow a healthful eating pattern that can lower her risk for developing this condition. Her dietitian recommends a goal of 450 to 600 kcal per meal and advises Ella to follow the Acceptable Macronutrient Distribution Range (AMDR) for carbohydrates and the Dietary Guidelines for Americans 2015-2020, which recommend limiting added sugar. She also recommends that Ella choose whole grains rather than processed grains. Ella decides to pack a lunch to take to work every day. This morning she’s making a sandwich for her lunch. Categories of Sandwich Options (Top of the screen) Breads Spreads Cheeses Vegetables Proteins Specific food items to select White Bread 6-inches Honey Mustard Provolone LettuceTomatoBell Peppers Turkey Part A - Reading Nutrition Facts Panels for Total Kilocalories How many total kilocalories are in Ella’s sandwich? _____…arrow_forward, if one of the archaeological specimens lacked the celiac disease-causing epitope, how could PCR be used to identify the allele in a contemporary germplasm collection of wild wheats, and to assist in transferring the allele to modern wheat varieties?arrow_forwardNow you will consider the composition of lipoproteins, including where they are synthesized, how they circulate, and where the various lipid and protein components are located within the lipoprotein molecule. Drag the appropriate labels to their respective targets.arrow_forwardThe Oregon Wolfe Barley mapping population is unique in having 12 easily-scored morphological markers, each showing monogenic inheritance. Do you consider these markers useful? Briefly defend your answer, pointing out advantages and disadvantages of morphological vs. molecular markers.arrow_forwardBiopharmaceutics and Pharmacokinetics:Two-Compartment Model Instant Absorption Questions Calculate these : a) B1, b) B2, c) hybrid rate constant (1) d) hybrid rate constant (2) e) t1/2,dist f) t1/2,elim g) k10 h) k12 i) k21 j) initial concentration (C0) k) central compartment volume (V1) l) steady-state volume (Vss) m) clearance (CL) AUC (0→10 min) using trapezoidal rule n) AUC (20→30 min) using trapezoidal rule o) AUCtail (AUC360→∞) p) total AUC (using short cut method) q) volume from AUC (VAUC)arrow_forwardIn a population of Jackalopes (pictured below), horn length will vary between 0.5 and 2 feet, with the mean length somewhere around 1.05 feet. You pick Jackalopes that have horn lengths around 1.75 feet to breed as this appears to be the optimal length for battling other Jackalopes for food. After a round of breeding, you measure the offsprings' mean horn length is 1.67. What is the heritability of horns length (h2)? Is Jackalope horn length a heritable trait? (4 pts)? 12pt v R Paragraph V BIU A श्र > Barrow_forwardThere are many differences between DNA replication happening during mitosis in a Douglas fir tree growing in the Oregon Cascade Mountains and DNA replication happening during a PCR reaction in a forestry research lab at Oregon State University where the laboratory is amplifying a Simple Sequence Repeat. Complete the following table that compares the two DNA replication events in terms of the primers, the nucleotides, the polymerase, and the target sequence. Additionally, give a general value for the number of copies of the template DNA after one S phase in one cell and after the lab has completed the PCR reaction. Tree SSR Type your answer here: Primers Nucleotides Polymerase Target sequence Number of copiesarrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning
Biology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning
Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning
Human Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning
Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax