This lesson introduces biotechnology and recombinant DNA technology, then explains how microbial enzymes make DNA engineering possible. These tools allow scientists to join genetic material from different sources and study or use the resulting molecules.
Biotechnology is the use of living systems to benefit people. Farming and selective breeding are longstanding forms of biotechnology. In modern usage, biotechnology often refers to deliberately altering an organism’s genetic material through genetic engineering.
All flashcards
What is a restriction enzyme?
An enzyme that recognizes a particular DNA sequence and cuts DNA at defined positions.
How do sticky ends help join DNA fragments?
Complementary single-stranded overhangs can pair through hydrogen bonds, aligning fragments before ligation.
What does DNA ligase do during recombinant DNA construction?
It covalently joins DNA backbones, sealing aligned fragments into a continuous DNA molecule.
What does a cDNA library represent?
DNA copies of RNA sequences expressed in the sampled cells or tissue, generally without introns or promoters.
How can a modified Ti plasmid deliver DNA to plant cells?
It uses Agrobacterium’s natural DNA-transfer process after tumor-causing genes are removed and desired DNA is inserted.
Quiz questions
What is the primary role of an origin of replication in a plasmid vector?Answer: It enables the plasmid to replicate in a host cell.
What does antibiotic selection establish when bacteria grow on antibiotic-containing medium?Answer: It favors cells carrying a plasmid with the relevant resistance gene.
In standard blue-white screening, why are white colonies candidates for recombinant plasmids?Answer: An insert in the lacZ region can disrupt beta-galactosidase function.
Why can a phage-based genomic library require fewer clones than a typical plasmid library?Answer: Phage vectors can accommodate larger DNA inserts.
How does electroporation promote DNA entry into eukaryotic cells?Answer: A brief electric pulse creates temporary pores in the cell membrane.
Based on Microbiology by Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Philip Lister, Brian M. Forster (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.