Biological Science (7th Edition)
7th Edition
ISBN: 9780134678320
Author: Scott Freeman, Kim Quillin, Lizabeth Allison, Michael Black, Greg Podgorski, Emily Taylor, Jeff Carmichael
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 16, Problem 6TYU
A minimal genetic code requires only 21 codons–one for each amino acid, and one for a stop signal. Given this, what advantage might be offered by having a code with 64 codons?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
The genetic code is thought to have evolved to maximize genetic stability by minimizing the effect on protein function of most substitution mutations (single-base changes). We will use the six arginine codons to test this idea. Consider all of the substitutions that could affect all of the six arginine codons.(a) How many total mutations are possible?(b) How many of these mutations are “silent,” in the sense that the mutantcodon is changed to another Arg codon?(c) How many of these mutations are conservative, in the sense that an Argcodon is changed to a functionally similar Lys codon?
The following pattern has been observed in the genetic code. For many codons, the first base specifies a biosynthetic precursor: U = pyruvate, C = α-ketoglutarate, A = oxaloacetate, G = any of a number of simple precursors. The second base of the codon tends to be associated with water solubility: water-soluble amino acids have a G, A, or C as the middle position, whereas five of seven of the most hydrophobic amino acids have U as the middle base. The third base in a codon is often information free; that is, many of the codons for the same amino acid differ only with the third base. Review amino acid biosynthesis and determine which amino acids obey these rules. What are the exceptions?
During planetary exploration a new life form is discovered which has a DNA
genome containing 6 different bases rather than the familiar four. The life form
contains proteins with 25 different amino acids. Codons on Earth comprise three
nucleotides; assuming a non-overlapping genetic code that includes initiation and
termination codons, how many nucleotides would you predict to constitute a
codon in the new life form, assuming all codons to be the same length? Briefly
explain your answer.
Chapter 16 Solutions
Biological Science (7th Edition)
Ch. 16 - 2. Which of the following is an important...Ch. 16 - Prob. 3TYKCh. 16 - A minimal genetic code requires only 21 codons–one...Ch. 16 - MODEL Draw a hypothetical metabolic pathway in...Ch. 16 - Prob. 11PIATCh. 16 - Prob. 12PIATCh. 16 - 13. A small portion of the human transport protein...Ch. 16 - Prob. 14PIAT
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- If the genetic code uses triplets, how many different amino acids can be coded by a repeating RNA polymer composed of UA and UC (UAUCUAUCUAUC ...)? a. one b. two c. three d. four e. fivearrow_forwardCodons in the set CUU, CUC, CUA, and CUG all code for the amino acid leucine. In this set, the first and second bases are identical; the identity of the third base is irrelevant. For what other sets of codons is the third base also irrelevant? For what amino acid(s) does each set code?arrow_forwardKnowing that the genetic code is almost universal, a scientist uses molecular biological methods to insert the human β-globin gene (Shown in Figure 17.11) into bacterial cells, hoping the cells will express it and synthesize functional β-globin protein. Instead, the protein produced is nonfunctional and is found to contain many fewer amino acids than does β-globin made by a eukaryotic cell. Explain why.arrow_forward
- What does it mean when we say that the genetic code is degenerate? Discuss the universality of the genetic code.arrow_forwardThe amino acid glycine is encoded by four codons: GGA, GGC, GGG, and GGU. Which of the following statements correctly explains this fact? The glycine anticodon contains the sequence CC, but the 5' base of the anticodon can pair nonspecifically with the 3' base of the codon. The glycine anticodon contains the sequence CC, but the 3' base of the anticodon can pair nonspecifically with the 5' base of the codon. Glycine tRNA has four anticodons, and the appropriate anticodon specifically pairs with the correct codon. There are four tRNAs for glycine, each of which has an anticodon that specifically pairs with the correct codon. all of the abovearrow_forwardWhat is meant by the statement “The genetic code is universal”? What is the significance of this finding?arrow_forward
- The genetic code was solved partly by the use of in vitro systems to translate synthetic RNAs into peptides. In these systems, ribosomes, amino acids, and buffers that support translation are added and there is no control of where translation begins. AAA = Lys; AUA = Ile; AAU = Asn; UAA = stop. What peptides would NOT be produced in an in vitro system if the following oligonucleotide were added: AAAAAAAAAUAAAAAAAA Select one: a) Lys-Lys-Lys-Lys-Lys-Lys-Lys-Lys b) Lys-Lys-Ile-Lys-Lys c) Lys-Lys-Asn-Lys-Lysarrow_forwardConsider the following original coding sequence of a gene that codes for a short 5- amino acid polypeptide: 5'-ATGGGCTCGAACTCATAA-3' Using the genetic code and the amino acid table below, which of the following sequences arises from a non-conservative missense mutation in the original sequence shown above? First base in codon U U A UUU UUC- UUA UUG- CUU CUC CUA CUG- U Phe (F) Leu (L) Leu (L) Second base in codon Val (V) UCU - UCC UCA UCG CCU CCC CCA CCG AUU ACU- AUC Ile (1) ACC AUA- ACA AUG Met (M) start ACG GUU GCU- GUC GCC GUA GCA GUG GCG- C Ser (S) Pro (P) Thr (T) Ala (A) UAU UAC UAAT UAG CAU CAC CAA CAG AAU AAC AAA AAG GAU GAC GAA GAG A Tyr (Y) STOP His (H) Gln (Q) Asn (N) Lys (K) Asp (D) Glu (E) G UGU UGC UGA STOP UGG Trp (W) Cys (C) CGU CGC CGA CGG AGU AGC AGA 1 AGG GGU- GGC GGA GGG Arg (R) Ser (S) Arg (R) Gly (G) U C A G U C A G U C A G U C A G Last base in codonarrow_forwardHow many codons would exist in a genetic code that had codons that were four bases long? Why? (show the equation for calculation)arrow_forward
- An RNA polymer is made by using the enzyme polynucleotide phosphorylase with equal quantities of CTP and GTP. When this RNA is used in an in vitro translation system, all of the following amino acids could be incorporated into a newly made polypeptide, except: Codon Table Second position C UUU UCU UAU UGU phe tyr сys UUC UCC UAC UGC ser UAA Stop UGA Stop UAG Stop UGG trp UUA UCA UUG UCG CUU CCU CAU CGU leu his ССС pro ССА CỤC САС CGC arg CỦA САА CGA gln CUG CCG CAG CGG AUU ACU AAU AGU asn ser AUC ile ACC thr АCА AAC AGC AUA AAA lys AAG AGA arg AUG met ACG AGG GUU GCU GAU GGU asp GUC GCC ala GCA GẠC GGC val gly GUA GAA GGA glu GUG GCG GAG GGG glycine (Gly) histidine (His) proline (pro) alanine (Ala) arginine (Arg) Third position (3'-end) AGUCAG First position (5'-end)arrow_forward. The genetic code is thought to have evolved to maximize genetic stability by minimizing the effect on protein function of most substitution muta- tions (single-base changes). We will use the six arginine codons to test this idea. Consider all of the substitutions that could affect all of the six arginine codons. (a) How many total mutations are possible? (b) How many of these mutations are "silent," in the sense that the mutant codon is changed to another Arg codon? (c) How many of these mutations are conservative, in the sense that an Arg codon is changed to a functionally similar Lys codon?arrow_forwardWhat does it mean when we say that the genetic code contains degeneracy? Discuss the universality of the genetic code.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning
Human Heredity: Principles and Issues (MindTap Co...
Biology
ISBN:9781305251052
Author:Michael Cummings
Publisher:Cengage Learning
QCE Biology: Introduction to Gene Expression; Author: Atomi;https://www.youtube.com/watch?v=a7hydUtCIJk;License: Standard YouTube License, CC-BY