• Stellenbosch University-South Africa

• BIOCHEMIST 214

Biochemie - Biochemistry - 214

Dashboard / My courses / Biochemie - Biochemistry - 214 / Aanlyn Toetse / Online Tests: / TEST A1 Theme A to D

Started on Thursday, 29 April 2021, 17:30

State Finished

Completed on Thursday, 29 April 2021, 19:45

Time taken 2 hours 15 mins

Grade 59.00 out of 80.00 (74%)

Question 1

Correct

Mark 1.00 out of 1.00

Indicate if the following statement is True or False

The trans conformation of the peptide bond occurs most frequently in nature at a ratio of 2:1 with that of the cis conformation. / Die trans konformasie van die

peptied binding vind meestal in die natuur plaas teen 'n verhouding van 2:1 met dié van die cis-konformasie.

Select one:

True

False 

The correct answer is 'False'.

Question 2

Incorrect

Mark 0.00 out of 1.00

Question 3

Correct

Mark 1.00 out of 1.00

A part of a nucleotide sequence of the template DNA-chain (“anti-sense”) is as follows: / ’n Gedeelte van ’n nukleotiedvolgorde van ’n templaat DNA-string

(“anti-sin”) is soos volg:

5’……TTATCTACCATTGGGGGTGCATAC..…. 3’

Examine the following statement about the above DNA sequence and mark your choice (a, b, c, d or e). / Bestudeer die onderstaande stelling oor die

bostaande DNA volgorde en merk u keuse (a, b, c, d of e).

The number of different tRNA molucules necessary to translate the mRNA is: / Die aantal verskillende tRNA molekules wat nodig is om die mRNA te transleer

(vertaal) is:

Select one:

A. 8

B. 5

C. 24

D. None of the choices / Geen van die keuses

E. 6

The correct answer is: 5

Indicate if the following statement is True or False

The D-form of amino acids are the most commonly found form in proteins. / Die D-form van amino sure is die mees herkenbare vorm in proteïne.

Select one:

True

False 

The correct answer is 'False'.

Question 4

Correct

Mark 1.00 out of 1.00

Question 5

Complete

Mark 10.00 out of 15.00

Indicate if the following statement is True or False

The liquid phase of water is denser than its solid phase. / Die vloeibare fase van water is meer dens as die van sy soliede fase.

Select one:

True 

False

The correct answer is 'True'.

Consider the following peptide: / Beskou die volgende peptide:

Met-Ala-Lys-Tyr-His-Glu

A. Draw the structure of the peptide at pH 9.5. Make sure you show all the atoms and clearly indicate all the charges on the appropriate groups. / Teken die struktuur

van die peptied by ʼn pH van 9.5. Maak seker jy wys al die atome aan en die ladings op die toepaslike groepe. [10]

B. Calculate the pH at which the molecule exists as a zwitter-ion. Bereken die pH waar die molekuul as 'n zwitterioon voorkom. [5]

5.pdf

Question 6

Complete

Mark 8.00 out of 8.00

Question 7

Correct

Mark 1.00 out of 1.00

Calculate the ratio of the ionic species which is protonated (has acid properties) relative to the deprotonated form in a dilute solution of the below peptide at pH 4.0 /

Bereken die persentasie van die ioniese spesie wat geprotoneerd is (het suur eienskappe) relatief tot die degeprotoneerde vorm in 'n verdunde oplossing van die

onderstaande peptied by pH 4.0

Glu-Arg-Leu

As part of your answer, also write down the ionization equation for the peptide. / As deel van jou antwoord, skryf ook die ioniserings vergelyking vir die peptied

neer.