Flashcards: Molecular Tools: Restriction Enzymes and Modifications — 22 cards

Restriction Enzymes — types?

Type I, II, and III, differ in recognition and cleavage.

Nomenclature system — basis?

Organism name + discovery order (Roman numerals).

Type II enzymes — recognition?

Recognize palindromic sequences and cut within or at recognition site.

Restriction enzyme cleavage — types?

Sticky ends (overhangs) or blunt ends.

Applications of restriction enzymes?

Gene cloning, DNA mapping, fingerprinting, SNP analysis.

Modification enzymes — examples?

Methylases, phosphatases, ligases, kinases.

Phosphatases — function?

Remove phosphate groups from molecules.

Methylases — role?

Add methyl groups to DNA or proteins, affecting regulation.

Ligases — mechanism?

Join DNA fragments by forming phosphodiester bonds.

Polynucleotide kinase — activity?

Phosphorylates 5’ ends of DNA or RNA.

RNase types — examples?

RNase A (single-stranded RNA), RNase H (RNA-DNA hybrids).

Restriction enzymes — classification?

Type I (distant cut), II (within recognition), III (near recognition).

Restriction enzyme recognition sites?

Specific, often palindromic DNA sequences.

Sticky vs blunt ends?

Sticky have overhangs; blunt are straight cuts.

Restriction enzyme applications?

Cloning, DNA fingerprinting, SNP detection.

Modification enzymes — purpose?

Protect DNA from restriction, modify nucleic acids.

Phosphatases — role in cloning?

Remove 5’ phosphate to prevent self-ligation.

Methylation — effect?

Regulates gene expression, protects bacterial DNA.

Ligase — cofactors?

ATP or NAD+ depending on type.

Polynucleotide kinase — use?

Label DNA ends or prepare for ligation.

RNase — function?

Degrade RNA, involved in RNA processing and defense.

Restriction enzyme classification — basis?

Recognition sequence, cleavage pattern, cofactors.