Chapter 13, Translation and Proteins Video Solutions, Essentials of Genetics

Problem 1

In this chapter, we focused on the translation of mRNA into proteins as well as on protein structure and function. Along the way, we found many opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanations given in the chapter, what answers would you propose to the following fundamental questions:
(a) What experimentally derived information led to Holley's proposal of the two-dimensional cloverleaf model of tRNA?
(b) What experimental information verifies that certain codons in mRNA specify chain termination during translation?
(c) How do we know, based on studies of Neurospora nutritional mutations, that one gene specifies one enzyme?
(d) On what basis have we concluded that proteins are the end products of genetic expression?

Jennifer Stoner

Numerade Educator

00:45

Problem 2

Review the Chapter Concepts list on p. $241 .$ These all relate to the translation of genetic information stored in mRNA into proteins and how chemical information in proteins imparts function to those molecules. Write a brief essay that discusses the role of ribosomes in the process of translation as it relates to these concepts.

Jennifer Stoner

Numerade Educator

00:40

Problem 3

List and describe the role of all molecular constituents present in a functional polyribosome.

Hunza Gilgit

Numerade Educator

02:56

Problem 4

Contrast the roles of tRNA and mRNA during translation, and list all enzymes that participate in the translation processes.

Maryam Riaz

Numerade Educator

04:15

Problem 5

Francis Crick proposed the adaptor hypothesis for the function of tRNA. Why did he choose that description?

Dennis Howard

Numerade Educator

01:07

Problem 6

During translation, what molecule bears the anticodon? The codon?

Jackson Miner

Numerade Educator

00:23

Problem 7

Summarize the steps involved in charging tRNAs with their appropriate amino acids.

Sam Limsuwannarot

Numerade Educator

04:02

Problem 8

Each transfer RNA requires at least four specific recognition sites that must be inherent in its tertiary protein structure in order for it to carry out its role. What are these sites?

Syed Vasi

Numerade Educator

05:19

Problem 9

What are the major differences between translation in bacteria and translation in eukaryotes?

Shiksha Dutta

Numerade Educator

02:12

Problem 10

Explain why the one-gene:one-enzyme hypothesis is no longer considered to be totally accurate.

Eric Goldman

Numerade Educator

02:07

Problem 11

Hemoglobin is a tetramer consisting of two $\alpha$ and two $\beta$ chains. What level of protein structure is described in this statement?

Danielle Ashley

Numerade Educator

View

Problem 12

Using sickle-cell anemia as a basis, describe what is meant by a genetic or inherited molecular disease. What are the similarities and dissimilarities between this type of a disorder and a disease caused by an invading microorganism?

Susan Hallstrom

Numerade Educator

View

Problem 13

Describe the genetic and molecular basis of sickle-cell anemia.

Susan Hallstrom

Numerade Educator

00:24

Problem 14

Assuming that each nucleotide is $0.34 \mathrm{nm}$ long in mRNA, how many triplet codes can simultaneously occupy space in a ribosome that is 20 nm in diameter?

Sam Limsuwannarot

Numerade Educator

02:48

Problem 15

Review the concept of colinearity in Section $12.5(\mathrm{p} .226)$ and consider the following question: Certain mutations called amber in bacteria and viruses result in premature termination
of polypeptide chains during translation. Many amber mutations have been detected at different points along the gene that codes for a head protein in phage T4. How might this system be further investigated to demonstrate and support the concept of colinearity?

Bryan Lynn

Numerade Educator

01:49

Problem 16

In your opinion, which of the four levels of protein organization is the most critical to a protein's function? Defend your choice.

Vishal Sharma

Numerade Educator

00:37

Problem 17

List and describe the function of as many nonenzymatic proteins as you can that are unique to eukaryotes.

Amy Jiang

Numerade Educator

01:25

Problem 18

How does an enzyme function? Why are enzymes essential for living organisms?

David Collins

Numerade Educator

04:30

Problem 19

Shown in the following table are several amino acid substitutions in the $\alpha$ and $\beta$ chains of human hemoglobin. Use the genetic code table in Figure 12.7 to determine how many of them can occur as a result of a single nucleotide change.

Jessica Honkomp

Numerade Educator

View

Problem 20

Three independently assorting genes are known to control the biochemical pathway below that provides the basis for flower color in a hypothetical plant
colorless $\stackrel{A^{-}}{\longrightarrow}$ yellow $\stackrel{B-}{\longrightarrow}$ green $\stackrel{C-}{\longrightarrow}$ speckled
Homozygous recessive mutations, which disrupt enzyme function controlling each step, are known. Determine the phenotypic results in the $\mathrm{F}_{1}$ and $\mathrm{F}_{2}$ generations resulting from the $\mathrm{P}_{1}$ crosses involving true-breeding plants given here.
(a) speckled $(A A B B C C) \times$ yellow $(A A b b C C)$
(b) yellow $(A A b b C C) \times$ green $(A A B B c c)$
(c) colorless $(a a B B C C) \times$ green $(A A B B c c)$

Susan Hallstrom

Numerade Educator

04:28

Problem 21

How would the results in cross (a) of Problem 20 vary if genes $A$ and $B$ were linked with no crossing over between them? How would the results of cross (a) vary if genes $A$ and $B$ were linked and 20 map units apart?

Danielle Ashley

Numerade Educator

03:31

Problem 22

A series of mutations in the bacterium Salmonella typhimurium results in the requirement of either tryptophan or some related molecule in order for growth to occur. From the data shown here, suggest a biosynthetic pathway for tryptophan.

Khalida Dawar

Numerade Educator

00:51

Problem 23

The emergence of antibiotic-resistant strains of Enterococci and transfer of resistant genes to other bacterial pathogens have highlighted the need for new generations of antibiotics to combat serious infections. To grasp the range of potential sites for the action of existing antibiotics, sketch the components of the translation machinery (e.g., see Step 3 of Figure 13.6), and using a series of numbered pointers, indicate the specific location for the action of the antibiotics shown in the following table.

Grant Castaneda

Numerade Educator