Question 1

Which statement concerning the monosaccharide portion of nucleotides is true in every case?

Accepted Answer

A) The monosaccharide is in the pyranose form. 
B) The linkage to phosphate is at carbon #3. 
C) The heterocyclic base is attached to carbon #1 of the monosaccharide. 
D) The monosaccharide-nitrogen base linkage is $\infty$. 
E) The monosaccharide is 2-deoxy-d-ribose. 
A) The monosaccharide is in the pyranose form. 
B) The linkage to phosphate is at carbon #3. 
C) The heterocyclic base is attached to carbon #1 of the monosaccharide. 
D) The monosaccharide-nitrogen base linkage is $\infty$. 
E) The monosaccharide is 2-deoxy-d-ribose.

Question 2

Which is the initial N-terminal amino acid in the developing polypeptide in bacteria?

Accepted Answer

A) Cysteine 
B) Methionine 
C) N-Formylmethionine 
D) Glycine 
E) Alanine 
A) Cysteine 
B) Methionine 
C) N-Formylmethionine 
D) Glycine 
E) Alanine

Question 3

The base sequence of the DNA is known as:

Accepted Answer

A) Gene 
B) Primary structure 
C) Beta sheet structure 
D) Tertiary structure 
E) Secondary structure 
A) Gene 
B) Primary structure 
C) Beta sheet structure 
D) Tertiary structure 
E) Secondary structure

Question 4

For the following statements,answer yes or no:
a)Does a nucleoside have an C-substituted glycoside? Yes/No
b)Does a nucleotide have a N-substituted glycosidic ester of phosphoric acid.Yes/No
c)Does the DNA polymer have the form of a double helix with the pyrimidine and purine base structures oriented toward the exterior of the helix? Yes/No
d)Does hydrogen bonding between complementary bases make possible the double helix DNA structure,as well as replication of the DNA molecule? Yes/No

Accepted Answer

A: No; B:

Question 5

Draw the structures to represent what is likely to happen when cyclic AMP (3',5'-cyclic adenylic acid)reacts with aqueous sodium hydroxide,briefly explaining your rationale.

Accepted Answer

@#IMG-DLM& The reaction appears to follow an S_N2 me

Question 6

Consideration of tautomerism in guanine suggests that it can exist in lactam and lactim forms.The form that is typically found in DNA is ___,typically pairs with ___,while the other form is likely to pair with ___,leading to the possible spontaneous mutations.

Accepted Answer

A) lactam,cytosine,thymine 
B) lactam,cytosine,adenine 
C) lactim,cytosine,thymine 
D) lactam,uracil,cytosine 
E) lactim,cytosine,uracil 
A) lactam,cytosine,thymine 
B) lactam,cytosine,adenine 
C) lactim,cytosine,thymine 
D) lactam,uracil,cytosine 
E) lactim,cytosine,uracil

Question 7

Explain why 3 bases (triplet code)are needed in the genetic code to unambiguously identify each amino acid.

Accepted Answer

There are only four bases and 20 amino a

Question 8

Primers are needed for the enzyme polymerase

Accepted Answer

A) To start adding nucleotides on the 5' end until the template is fully copied. 
B) To start copying the template on the 3' end until a stop codon. 
C) To start adding nucleotides on the 3' end of it until it copies the full template. 
D) To start polymerizing nucleotides on the template. 
E) To copy the template and the primers themselves until turning of the PCR. 
A) To start adding nucleotides on the 5' end until the template is fully copied. 
B) To start copying the template on the 3' end until a stop codon. 
C) To start adding nucleotides on the 3' end of it until it copies the full template. 
D) To start polymerizing nucleotides on the template. 
E) To copy the template and the primers themselves until turning of the PCR.

Question 9

Hydrolysis of DNA from various species gives which of the following results?

Accepted Answer

A) The mole percentage of adenine is approximately equal to that of thymine. 
B) The mole percentage of cytosine is approximately equal to that of guanine. 
C) The total mole percentage of purines is approximately equal to that of pyrimidines. 
D) The mole percentage of adenine is approximately equal to that of cytosine. 
E) More than one of these choices is correct. 
A) The mole percentage of adenine is approximately equal to that of thymine. 
B) The mole percentage of cytosine is approximately equal to that of guanine. 
C) The total mole percentage of purines is approximately equal to that of pyrimidines. 
D) The mole percentage of adenine is approximately equal to that of cytosine. 
E) More than one of these choices is correct.

Question 10

Supply the missing reagent in the following synthesis.

Accepted Answer

A) (CH3)2C=O 
B) HOCH2CH2OH 
C) CH3CHOHCH3 
D) CH3CCl2CH3 
E) CH3CHClCH3 
A) (CH3)2C=O 
B) HOCH2CH2OH 
C) CH3CHOHCH3 
D) CH3CCl2CH3 
E) CH3CHClCH3

Question 11

In the synthesis of cytidine (Bz protected),the amino group at position 4 (N4)of cytosine is protected with a benzoyl protecting group because

Accepted Answer

A) the primary amino group would react faster than the secondary N1. 
B) The cytosine reagent would not be soluble in the reaction medium. 
C) Cytosine needs to be activated with the benzoyl protecting group. 
D) The amino group needs to remain protected after hydrolysis of benzoyl groups. 
E) The activation of the primary is needed for the reaction with the d-ribose. 
A) the primary amino group would react faster than the secondary N1. 
B) The cytosine reagent would not be soluble in the reaction medium. 
C) Cytosine needs to be activated with the benzoyl protecting group. 
D) The amino group needs to remain protected after hydrolysis of benzoyl groups. 
E) The activation of the primary is needed for the reaction with the d-ribose.

Question 12

List anticodon sequences on the tRNAs carrying the amino acids: Ala,Phe,Leu,Tyr.

Accepted Answer

The answer of List anticodon sequences on the tRNAs carrying...

Question 13

What is the function of the RNA polymerase?

Accepted Answer

It joins the ribonuc

Question 14

Which is the predominant tautomeric form of guanine when it is present in DNA?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 15

The time required to synthesize a protein depends on the number of amino acid residues it contains.A rough estimate is that each ribosome can cause ___ peptide bonds to be formed per minute.

Accepted Answer

A) 30 
B) 50 
C) 100 
D) 150 
E) 200 
A) 30 
B) 50 
C) 100 
D) 150 
E) 200

Question 16

What statement is false?

Accepted Answer

A) mRNA migrates into the cytoplasm after the introns are removed in the nucleus. 
B) The ribosomes are formed by approximately two-thirds RNA and one-third protein. 
C) The 30S subunit of the ribosome carries catalytic activity for translation. 
D) The 30S and 50S subunits are components of the ribosomal RNA. 
E) The 50S subunit joins one amino acid to the next by an amide bond. 
A) mRNA migrates into the cytoplasm after the introns are removed in the nucleus. 
B) The ribosomes are formed by approximately two-thirds RNA and one-third protein. 
C) The 30S subunit of the ribosome carries catalytic activity for translation. 
D) The 30S and 50S subunits are components of the ribosomal RNA. 
E) The 50S subunit joins one amino acid to the next by an amide bond.

Question 17

Which bases pair in DNA by hydrogen bonding?

Accepted Answer

A) Cytosine and thymine 
B) Cytosine and uracil 
C) Adenine and guanine 
D) Adenine and thymine 
E) Adenine and uracil 
A) Cytosine and thymine 
B) Cytosine and uracil 
C) Adenine and guanine 
D) Adenine and thymine 
E) Adenine and uracil

Question 18

Draw the structure of the dinucleotide A-T.

Accepted Answer

The answer of Draw the structure of the dinucleotide A-T....

Question 19

If the base sequence along a segment of DNA were T-C-G-T-A,what would be the antisense oligonucleotide synthesized from this sequence?

Accepted Answer

A) G-C-C-A-T 
B) C-G-G-T-A 
C) U-G-C-U-T 
D) A-G-C-A-U 
E) A-G-C-A-T 
A) G-C-C-A-T 
B) C-G-G-T-A 
C) U-G-C-U-T 
D) A-G-C-A-U 
E) A-G-C-A-T

Question 20

What is the acid-labile protecting group used for the carbohydrate during the laboratory synthesis of oligonucleotides.

Accepted Answer

A) "$\beta$-Cyanoethyl" 
B) "Dimethoxyisopropylamine" 
C) "Dimethoxytrityl" 
D) "Dimethoxytriptamine" 
E) "Phosphoramidite" 
A) "$\beta$-Cyanoethyl" 
B) "Dimethoxyisopropylamine" 
C) "Dimethoxytrityl" 
D) "Dimethoxytriptamine" 
E) "Phosphoramidite"

Exam 25: Nucleic Acids and Protein Synthesis

Which statement concerning the monosaccharide portion of nucleotides is true in every case?

Which is the initial N-terminal amino acid in the developing polypeptide in bacteria?

The base sequence of the DNA is known as:

Draw the structures to represent what is likely to happen when cyclic AMP (3',5'-cyclic adenylic acid)reacts with aqueous sodium hydroxide,briefly explaining your rationale.

Consideration of tautomerism in guanine suggests that it can exist in lactam and lactim forms.The form that is typically found in DNA is ___,typically pairs with ___,while the other form is likely to pair with ___,leading to the possible spontaneous mutations.

Explain why 3 bases (triplet code)are needed in the genetic code to unambiguously identify each amino acid.

Primers are needed for the enzyme polymerase

Hydrolysis of DNA from various species gives which of the following results?

Supply the missing reagent in the following synthesis.

In the synthesis of cytidine (Bz protected),the amino group at position 4 (N4)of cytosine is protected with a benzoyl protecting group because

List anticodon sequences on the tRNAs carrying the amino acids: Ala,Phe,Leu,Tyr.

What is the function of the RNA polymerase?

Which is the predominant tautomeric form of guanine when it is present in DNA?

The time required to synthesize a protein depends on the number of amino acid residues it contains.A rough estimate is that each ribosome can cause ___ peptide bonds to be formed per minute.

What statement is false?

Which bases pair in DNA by hydrogen bonding?

Draw the structure of the dinucleotide A-T.

If the base sequence along a segment of DNA were T-C-G-T-A,what would be the antisense oligonucleotide synthesized from this sequence?

What is the acid-labile protecting group used for the carbohydrate during the laboratory synthesis of oligonucleotides.

The Basics

Families of Carbon

Acids and Bases

Nomenclature and Conformations of Alkanes and Cycloalkanes

Stereochemistry

Nucleophilic Reactions

Alkenes and Alkynes I

Alkenes and Alkynes II

Nuclear Magnetic Resonance and Mass Spectrometry

Radical Reactions

Alcohols and Ethers

Alcohols From Carbonyl Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Reactions of Aromatic Compounds

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Reactions at the Α Carbon of Carbonyl Compounds

Condensation and Conjugate Addition Reactions of Carbonyl Compounds

Amines

Transition Metal Complexes

Carbohydrates

Lipids

Amino Acids and Proteins

Filters

Consideration of tautomerism in guanine suggests that it can exist in lactam and lactim forms.The form that is typically found in DNA is _,typically pairs with _,while the other form is likely to pair with ___,leading to the possible spontaneous mutations.

In the synthesis of cytidine (Bz protected),the amino group at position 4 (N⁴)of cytosine is protected with a benzoyl protecting group because