PAM Sequence (Protospacer adjacent motif) – Definition, Functions, Properties

PAM Sequence (Protospacer adjacent motif) - Definition, Functions, Properties

What is PAM Sequence (Protospacer adjacent motif)? Protospacer Adjacent Motif, or PAM, is a type of two-factor authentication that tells Cas to only cut the foreign DNA that is invading. Properties of PAM sequence Spacers/protospacers PAM sequences Functions of PAM Sequence 1. Role of PAM in spacer acquisition 2. Role of PAM in interference 3. … Read more

Theta Model of Replication – Definition, Mechanism

Theta Model of Replication - Definition, Mechanism

What is Theta Model of Replication? Theta structures are produced during the replication of circular DNA molecules (prokaryote DNA). Two replication forks can move independently around the DNA ring, and the structure resembles the Greek letter (theta) when viewed from above. Procedure of Theta (θ) Model of Replication There are three phases to the replication … Read more

Rolling Circle Replication –  Mechanism, Application

Rolling Circle Replication -  Mechanism, Application

What is Rolling circle replication? What Is Circular DNA? Mechanism of Rolling circle replication The Rolling circle replication is completed in the following steps; 1. Initiation of Rolling circle replication 2. Elongation of Rolling circle replication 3. Termination of Rolling circle replication As a summary, a typical DNA rolling circle replication has five steps Replication … Read more

CRISPR-Cas9 Gene Editing – Definition, Mechanism, Application

CRISPR-Cas9 Gene Editing - Definition, Mechanism, Application

What is gene/genome editing? Gene or genome editing refers to the deliberate and precise modification of an organism’s genetic material. This advanced biotechnological process allows for the targeted alteration of DNA sequences within a genome, facilitating the correction of genetic anomalies or the introduction of specific traits. Historically, the concept of gene editing traces its … Read more

Cas9 Protein – Structure, Types, Function

Cas9 Protein - Structure, Types, FunctionCas9 Protein - Structure, Types, Function

Name  Cas9 endonuclease Alternative name spCas9/spyCas9 Organism  Streptococcus pyogenes serotype M1 Molecular weight ~163KDa Gene  cas9 Location on chromosome 0.85 to 0.86Mb Protein CRISPR-associated endonuclease Cas9/Csn1 Cofactor Mg2+ Biological processing  Interference- defense response to phage.Maintaining CRISPR repeat sequences Functions DNA and RNA bindingMetal ion binding3’-5’ exonuclease activityEndonuclease activity  What is Cas9 Protein? Structure of Cas9 HNH … Read more

Semiconservative Replication of DNA – Mechanism

Semiconservative Replication of DNA - Mechanism

Mode of DNA replication Imagine yourself in 1953, right after the discovery of the double helix structure of DNA. What are some burning questions you and other scientists might have? One big question concerned DNA replication. The double helix shape of DNA gave a tantalising hint about how copying might happen. It seemed likely that … Read more

Okazaki Fragments – Definition, Discovery, Formation, Enzymes, Importance

Okazaki Fragments - Definition, Discovery, Formation, Enzymes, Importance

What are Okazaki Fragments? Okazaki Fragments Definition Okazaki fragments are short DNA sequences synthesized discontinuously on the lagging strand during DNA replication, which are later joined together to form a continuous strand. Why do okazaki fragments form? Why okazaki fragments are formed? Okazaki fragments form due to the inherent nature of DNA polymerase and the … Read more

cDNA library – Definition, Principle, Construction, Uses

cDNA library - Definition, Principle, Construction, Uses

What is cDNA library? Principle of cDNA library Process involved in the construction of cDNA library 1. Extraction of mRNA from the eukaryotic cell 2. cDNA construction In the process of creating cDNAs, there’s different approaches. They are described as follows: a. The RNAse method Step I: Annealing: Step II: Replacing RNA strand with DNA … Read more

What are Telomeres and Telomerases?

What are Telomeres and Telomerases?

A ribonucleoprotein known as telomerase, terminal transferase adds a repeat sequence of telomeres to the 3′ end of chromosomes, the length of which varies depending on species. In most eukaryotic organisms, the chromosomal ends are capped by a repeating sequence known as a telomere. Telomeres prevent DNA damage and chromosomal fusion at the chromosome’s end. … Read more

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