Skip to main content

Below are a few statements about enzymes and their molecular reaction functions.

 1. Below are a few statements about enzymes and their molecular reaction functions.

A.   Alkaline phosphatases remove 3' phosphates from DNA and RNA.

B. S1 nuclease removes single-stranded regions from partially double-stranded DNA.

C.  5' end-labeling of DNA molecules can be done by using polynucleotide kinase, which transfers a 32P-labelled phosphate group to the 5' end of dephosphorylated DNA.

D. 3'-5' exonuclease activity of Taq polymerase releases the reporter from the 3' end of Taqman probes in qPCR.

Which one of the following options represents a combination of all correct statements?

1. A and B

2. B and C

3. B and D

4. A and C

Answer: 2. B and C

Explanation:

           Enzyme(s)                                                                                 Function

 Type II restriction endonucleases                                Cleave DNA molecules at specific base sequences

  Alkaline phosphatase                                                  Removes terminal phosphates from the 5′ or 3′                                                                                                                         end (or both)

Polynucleotide kinase                                                    Adds a phosphate to the 5′-OH end of a                                                                                                           polynucleotide to  label it or permit ligation

Exonuclease III                                                              Removes nucleotide residues from the 3′ ends of                                                                                                  a DNA strand 

Terminal transferase                                                     Adds homopolymer tails to the 3′-OH ends of a                                                                                                         linear duplex  

  Bacteriophage λ exonuclease                                      Removes nucleotides from the 5′ ends of a                                                                                                     duplex to expose single-stranded 3′ ends .

S1 nuclease                                                                  Breaks down single-stranded DNA and RNA.

Comments

Post a Comment

Popular posts from this blog

Given below are protein domains and their binding specificities.

        1. Given below are protein domains and their binding specificities.   which  one of the following options represents all correct matches between column X and Column Y ? A-iii, B-i, C-ii, D-ii A-i, B-ii, C-iii, D-i A-iii, B-iii, C-i, D-ii A- i, B-iii, C-ii, D-i Answer  : 4. A-i, B-iii, C-ii, D-i Domains are distinct functional or structural units within a protein. Each domain usually has a specific role or facilitates an interaction, contributing to the protein's overall function. Domains can be present in various biological contexts, and similar domains may be found in proteins that perform different functions.  SH2 domains were first identified in proteins encoded by the genomes of tumor-causing (oncogenic) viruses. These domains are composed of approximately 100 amino acids and feature a conserved binding pocket that accommodates a phosphorylated tyrosine residue. The human genome encodes over 110 SH2 domains, which play a crucial role...
Post a Comment
Read more

Population density and how determining population size?

Population density: Population density measures the number of individuals living in a specific area. It is usually expressed as: When the individuals are not mobile.         Population Density = Total Population/land Area (sq km or sq mile)      2. When individuals are very mobile and frequently   move from one area to another, we can determine the number of population sizes by applying the mark-recapture technique.   Mark-recapture technique: The mark-recapture technique was first developed by C.G.J. Petersen in 1896 and later refined by F.W. Lincoln in 1930. It is commonly known as the Lincoln-Petersen index when used for closed populations.     Total population size (N) = Total individuals captured, marked (M1), and released in the first sample (S1) x Size of the second recaptured sample (S2)/ Number of marked individuals recaptured in the second sample (M2) N= S1 x S2 / M2 Question:   In an experiment to determine the nu...
Post a Comment
Read more

Differences Between RPM and RCF in Centrifugation

    Differences Between RPM and RCF in Centrifugation In centrifuge operation, it is crucial to differentiate between two distinct units of measurement: Relative Centrifugal Force (RCF) and Revolutions Per Minute (RPM). These units are fundamentally different and confusing them—though not uncommon—can compromise the integrity of an experiment. This discussion will explore RCF and RPM in greater detail and examine their relationship. **Revolutions Per Minute (RPM) Revolutions Per Minute (RPM) refers to the measurement of the rotational speed of a centrifuge rotor, indicating the number of complete rotations it performs in one minute. This metric quantifies the rotor's spinning velocity. Each centrifuge has a specific speed range that varies by model. For instance, a low-speed centrifuge may operate at a minimum of 300 RPM, while a high-speed centrifuge can reach speeds of up to 15,000 RPM. Additionally, ultracentrifuges, the most powerful type, can exceed 150,000 RPM. **Relativ...
Post a Comment
Read more