[BIOCHEMISTRY] Nucleic Acids p1

e. All

Components of nucleotides:

a. Nitrogenous base

b. Sugar

c. Phosphate group

d. a and b

e. All

a. Ribose

Monosaccharide of RNA.

a. Ribose

b. Deoxyribose

a. Ribose

Has OH on 2 prime carbon.

a. Ribose

b. Deoxyribose

b. Deoxyribose

Monosaccharide of DNA.

a. Ribose

b. Deoxyribose

b. Deoxyribose

Has H on 2 prime carbon.

a. Ribose

b. Deoxyribose

a. N base

In nucleotide, what is in the monosaccharide 1' carbon?

a. N base

b. OH

c. H

d. Phosphodiester bond

e. Phosphate group

c. H

In DNA nucleotide, what is in the monosaccharide 2' carbon?

a. N base

b. OH

c. H

d. Phosphodiester bond

e. Phosphate group

b. OH

In RNA nucleotide, what is in the monosaccharide 2' carbon?

a. N base

b. OH

c. H

d. Phosphodiester bond

e. Phosphate group

d. Phosphodiester bond

In nucleotide, what is in the monosaccharide 3' carbon?

a. N base

b. OH

c. H

d. Phosphodiester bond

e. Phosphate group

e. Phosphate group

In nucleotide, what is in the monosaccharide 5' carbon?

a. N base

b. OH

c. H

d. Phosphodiester bond

e. Phosphate group

c. Both

Nitrogenous base:

a. Purine

b. Pyrimidine

c. Both

d. None

b. I, II - Guanine, Adenine

Purines:

I. Guanine

II. Adenine

III. Cytosine

IV. Uracil

V. Thymine

a. I, II, III, IV, V

b. I, II

c. III, IV, V

d. I, II, III

e. IV, V

c. III, IV, V - Cytosine, Uracil, Thymine

Pyrimidine:

I. Guanine

II. Adenine

III. Cytosine

IV. Uracil

V. Thymine

a. I, II, III, IV, V

b. I, II

c. III, IV, V

d. I, II, III

e. IV, V

b. 2

Number of H bonds between Adenine and Thymine.

a. 1

b. 2

c. 3

d. 4

c. 3

Number of H bonds between Guanine and Cytosine.

a. 1

b. 2

c. 3

d. 4

e. All

DNA structure can be:

a. Primary

b. Secondary

c. Tertiary

d. a and b

e. All

f. All

DNA primary structure:

a. Deoxyribose

b. Individual bases: AG, TC

c. Phosphodiester bond

d. a and b

e. b and c

f. All

c. Both

DNA secondary structure:

a. 2 polynucleotides which can be antipallarel or helix

b. Base pairing: A-T, G-C

c. Both

d. None

b. Chargaff's rule

Qty A = Qty T

Qty C = Qty G

a. Huckle's rule

b. Chargaff's rule

c. Avogadro's rule

d. Burk's rule

c. DNA tertiary structure

Packed in histones which form chromatin.

a. DNA primary structure

b. DNA secondary structure

c. DNA tertiary structure

a. Form A

More compact and more helical form of DNA.

a. Form A

b. Form B

c. Form Z

d. a and b

e. b and c

f. All

b. Form B

Most common form of DNA which contains 10 base pair per turn.

a. Form A

b. Form B

c. Form Z

d. a and b

e. b and c

f. All

b. Form B

First describe by Watson and Crick.

a. Form A

b. Form B

c. Form Z

d. a and b

e. b and c

f. All

c. Form Z

Left handed helix wherein phosphate group is more toward the periphery of the helix.

a. Form A

b. Form B

c. Form Z

d. a and b

e. b and c

f. All

d. a and b - Form A and B

Right handed form of DNA.

a. Form A

b. Form B

c. Form Z

d. a and b

e. b and c

f. All

e. All

True about DNA structure:

a. Composed of two polynucleotide chains joined by H bonds between the bases

b. Two strands are complementary

c. Chains are antiparallel (one is 5'-3' paired with 3'-5')

d. a and b

e. All

a. Denaturation

Alkali or heat cause the strands of DNA to separate but do not break phosphodiester bonds.

a. Denaturation

b. Renaturation

c. Hybridization

d. Resonance

b. Renaturation

If strands of DNA are separated by heat and then the temperature is slowly decreased under the appropriate conditions, base pairs reform and complementary strands of DNA come back together.

a. Denaturation

b. Renaturation

c. Hybridization

d. Resonance

b. Renaturation

RNA to DNA.

a. Denaturation

b. Renaturation

c. Hybridization

d. Resonance

c. Hybridization

Single strand of DNA pairs with complementary base sequences on another strand of DNA or RNA.

a. Denaturation

b. Renaturation

c. Hybridization

d. Resonance

c. Chromatin

Consists of DNA complexed with histones in nucleosomes.

a. Chromatid

b. Chromosome

c. Chromatin

d. Histones

d. Histones

Relatively small, basic proteins with a high content of arginine and lysine.

a. Chromatin

b. Ghrelin

c. Leptin

d. Histones

a. Prokaryotes

Histones are not present in:

a. Prokaryotes

b. Eukaryotes

c. Both

a. R, K - Arginine and Lysine

Major amino acid present in histones.

a. R, K

b. R, L

c. A, K

d. A, L

a. Nucleosome core

Eight histone molecules form an octamer around which approximately 140 base pairs of DNA are wound.

a. Nucleosome core

b. Nucleotide core

a. True

DNA that joins one nucleosome core to the next is complexed with Histone 1.

a. True

b. False

a. Selenoid structure

"Beads on a string" nucleosomal structure of chromatin that is further compacted.

a. Selenoid structure

b. Cystenoid structure

c. Serenoid structure

d. Thyroxine structure

e. None

True about RNA structure except:

a. Sugar group is ribose

b. Has uracil rather than thymine

c. Single stranded

d. Some act as catalyst of reaction thus have enzymatic activity

e. None

e. All

Types of RNA.

a. mRNA

b. tRNA

c. rRNA

d. a and b

e. All

e. None

True about mRNA except:

a. Carries codon

b. Has 7-methylguanosine triphosphate cap on the 5' end

c. Has tail poly(A) tail (200 adenine (A) nucleotide) on the 3' end

d. Synthesized in the nucleus

e. None

e. None

True about structure of mRNA except:

a. Has 7-methylguanosine triphosphate cap on the 5' end

b. Has tail poly(A) tail (200 adenine (A) nucleotide) on the 3' end

c. N7 in the guanine is methylated

d. 2′-hydroxyl groups of the first and second ribose moieties may be methylated

e. None

f. None

True a about tRNA except:

a. Carries anticodon

b. Clover leaf structure

c. Relatively small, containing about 80 nucleotides

d. Its anticodon loop carries anticodon

e. It has CCA sequence which is amino acid attachment site

f. None

f. All

Modified nucleotides present in tRNA.

a. Pseudouridine (ψ)

b. Dihydrouridine (d)

c. Ribothymidine (t)

d. a and b

e. b and c

f. All

a. tRNA first loop

From the 5′ end. The d loop which contains dihydrouridine.

a. tRNA first loop

b. tRNA middle loop

c. tRNA third loop

d. tRNA CCA sequence

b. tRNA middle loop

Contains the anticodon, which base-pairs with the codon in mRNA.

a. tRNA first loop

b. tRNA middle loop

c. tRNA third loop

d. tRNA CCA sequence

c. tRNA third loop

ψ loop, contains both ribothymidine and pseudouridine.

a. tRNA first loop

b. tRNA middle loop

c. tRNA third loop

d. tRNA CCA sequence

d. tRNA CCA sequence

tRNA structure at the 3′ end that carries the amino acid.

a. tRNA first loop

b. tRNA middle loop

c. tRNA third loop

d. tRNA CCA sequence

f. All

True a about rRNA:

a. The associate with proteins to form ribosomes.

b. Contains many loops and extensive base-pairing

c. rRNA molecules differ in their sedimentation coefficients (S)

d. a and b

e. b and c

f. All

a. Sedimentation

rRNA molecules differ in their:

a. Sedimentation

b. Solubility

c. Solvation

d. Segregation

e. All

30s + 50s —> 70s

Prokaryotic ribosomes:

a. 30s

b. 50s

c. 70s

d. a and b

e. All

e. All

40s + 60s —> 80s

Eukaryotic ribosomes:

a. 40s

b. 60s

c. 80s

d. a and b

e. All

f. All - 52 proteins

rRNA in prokaryotes.

a. 16s

b. 23s

c. 5s

d. a and b

e. b and c

f. All

e. None - 83 proteins

rRNA in eukaryotes except:

a. 18s

b. 28s

c. 5s

d. 5.8s

e. None

f. All

RNA enzymes:

a. Ribozymes

b. Ribonuclease

c. Peptidyltransferase

d. a and b

e. b and c

f. All

a. Ribozymes

Usually precursors of rRNA which remove internal segments of themselves, splicing the ends together.

a. Ribozymes

b. Ribonuclease

c. Peptidyltransferase

b. Ribonuclease

Cleave other RNA molecules

a. Ribozymes

b. Ribonuclease

c. Peptidyltransferase

b. tRNA

RNase P is a ribonuclease that cleaves precursors of what RNA?

a. mRNA

b. tRNA

c. rRNA

c. Peptidyltranferase

Enzyme in protein synthesis.

a. Ribozymes

b. Ribonuclease

c. Peptidyltransferase

a. Chromatin

Protein-DNA complexes found on chromosomes, within the nucleus.

a. Chromatin

b. Chromolein

c. Chromatid

c. Starting point is Ori which is multiple in ProK and 1 in EuK

Starting point is Ori which ONE in ProK and MULTIPLE in EuK.

True about DNA replication mechanism except:

a. Occurs in the nucleus

b. Bidirectional

c. Starting point is Ori which is multiple in ProK and 1 in EuK

d. Semi conservative

e. Actual site is replication fork

f. None

b. Bidirectional

Means that replication begins at a site of origin and simultaneously moves out in both directions from this point.

a. Semiconservative

b. Bidirectional

c. Degenerate

d. Universal

a. Ori

Starting point of DNA replication.

a. Ori

b. Replication fork

c. Topoisomerase

d. Helicase

e. ssDNA binding protein

a. 1

How many ori in prokaryotes?

a. 1

b. 2

c. 3

d. Many

b. Replication fork

Actual site of DNA replication after it started in the Ori.

a. Ori

b. Replication fork

c. Topoisomerase

d. Helicase

e. ssBP

d. Helicase

For unwinding of dsDNA to ssDNA.

a. Ori

b. Replication fork

c. Topoisomerase

d. Helicase

e. ssBP

e. ssBP: Single Stranded Binding Protein

Prevent recoiling of ssDNA.

a. Ori

b. Replication fork

c. Topoisomerase

d. Helicase

e. ssBP

c. Topoisomerase

Prevent supercoiling of DNA.

a. Ori

b. Replication fork

c. Topoisomerase

d. Helicase

e. ssBP

a. Nuclease action

Topoisomerase has cutting action known as:

a. Nuclease action

b. Ligase action

b. Ligase action

Topoisomerase has joining action known as:

a. Nuclease action

b. Ligase action

a. Top I

Cut 1 strand.

a. Top I

b. Top II

c. Top III

d. a and b

e. All

b. Top II

Cut 2 strands.

a. Top I

b. Top II

c. Top III

d. a and b

e. All

b. Top II

DNA Gyrase is ________ in bacteria.

a. Top I

b. Top II

c. Top III

d. a and b

e. All

b. Fluoroquinolones

Drugs targeting topoisomerase.

a. Beta lactams

b. Fluoroquinolones

c. Macrolides

d. Monobactams

e. All

RNA primer:

a. Composed of short RNA strand: 10 RNA nucleotides

b. Synthesized via DNA primase

c. Important for DNA polymerase activation

d. a and b

e. All

b. DNA polymerase

Adds deoxyribonucleotides to the 3′-hydroxyls of the RNA primers and subsequently to the ends of the growing DNA strands.

a. RNA primer

b. DNA polymerase

c. Helicase

d. Topoisomerase

b. DNA Polymerase

For elongation, catalyze the synthesis of DNA.

a. RNA primer

b. DNA polymerase

c. Helicase

d. Topoisomerase

a. DNA Polymerase I

Has the following actions:

• Excision of primer

• Elongation activity to fill the gap; filling of the primer

• Proofreading

a. DNA polymerase I

b. DNA polymerase II

c.DNA polymerase III

a. DNA polymerase I

For repair and synthesis on the lagging strand.

a. DNA polymerase I

b. DNA polymerase II

c.DNA polymerase III

c. DNA Polymerase III

For the actual elongation and also has proof reading activity

a. DNA polymerase I

b. DNA polymerase II

c. DNA polymerase III

c. DNA polymerase III

Joins the Okazaki fragments; enzyme that catalyzes the formation of phosphodiester bonds between two polynucleotide chains.

a. DNA polymerase I

b. DNA polymerase II

c. DNA polymerase III

a. Elongation

Polymerase action

a. Elongation

b. Proofreading

c. Both

d. None

b. Proofreading

Exonuclease action

a. Elongation

b. Proofreading

c. Both

d. None

a. Leading strand

Continuous and advances the replication fork.

a. Leading strand

b. Lagging strand

b. Lagging strand

Okazaki fragments which discontinuous and grow away from the replication fork.

a. Leading strand

b. Lagging strand

a. 3' to 5'

Direction of copying of DNA polymerase.

a. 3' to 5'

b. 5' to 3'

e. All

DNA Polymerase types of prokaryotes

a. I

b. II

c. III

d. a and b

e. All

a. Elongation

5' to 3' polymerase enzyme activity indicate:

a. Elongation

b. Proofreading

c. Primer excision

b. Proofreading

3' to 5' exonuclease enzyme activity indicate:

a. Elongation

b. Proofreading

c. Primer excision

c. Primer excision

5' to 3' exonuclease enzyme activity indicate:

a. Elongation

b. Proofreading

c. Primer excision

f. All

Action of DNA Pol I.

a. Elongation

b. Proofreading

c. Primer excision

d. a and b

e. b and c

f. All

d. a and b

Action of DNA Pol III.

a. Elongation

b. Proofreading

c. Primer excision

d. a and b

e. b and c

f. All

e. Proliferating Cell Nuclear Antigen

Enhances processivity of the DNA polymerases; binds to many proteins present at the replication fork.

a. Primase

b. Helicase

c. Topoisomerase

d. DNA ligase

e. Proliferating Cell Nuclear Antigen

10^-9 to 10^-10 .

Fidelity of elongation is very high with an overall rate

a. Chromosome mutation

May be either changing the structure of a chromosome, or loss or gain of part of a chromosome.

a. Chromosome mutation

b. Gene mutation

b. Gene mutation

Change in the nucleotide sequence of a gene involving only a single nucleotide and may be due to copying errors, chemicals, viruses.

a. Chromosome mutation

b. Gene mutation

f. None

Chromosomes mutation except:

a. Deletion

b. Duplication

c. Translocation

d. Inversion

e. Non-disjunction

f. None

e. Non-disjunction

"No coming apart" wherein there is abnormal number of chromosomes due to homologous chromosomes failing to separate properly during meiosis.

a. Deletion

b. Duplication

c. Translocation

d. Inversion

e. Non-disjunction

a. Deletion

Involves the loss of all or part of a chromosome.

a. Deletion

b. Duplication

c. Translocation

d. Inversion

e. Non-disjunction

b. Duplication

Involves the production of extra copies of parts of chromosomes.

a. Deletion

b. Duplication

c. Translocation

d. Inversion

e. Non-disjunction

c. Translocation

When one part of a chromosome breaks off and attaches to another chromosomes.

a. Deletion

b. Duplication

c. Translocation

d. Inversion

e. Non-disjunction