Genetic Technologies in Molecular and Cellular Biology

Plasmids

Circular DNA molecules used in genetic engineering.

Antibiotic Resistance

Bacteria's ability to survive antibiotic treatment.

Penicillin

First antibiotic discovered by Alexander Fleming in 1928.

S. aureus

Bacteria with 90% resistance to penicillin today.

Vectors

Modified plasmids or phages for DNA transport.

Endonucleases

Enzymes that cut DNA at specific sites.

Restriction Endonucleases

Bacterial enzymes that degrade foreign DNA.

Recognition Sequences

Specific DNA sequences where restriction enzymes cut.

EcoRI

Restriction enzyme from E. coli.

SmaI

Restriction enzyme from S. marcescens.

Methylation

Modification of DNA to protect it from restriction enzymes.

Double-stranded DNA

DNA consisting of two complementary strands.

Recognition Sites

Specific sequences recognized by restriction enzymes.

Bacterial Genomes

Contain double-stranded DNA that can be cut.

Modification of Host DNA

Bacteria mark their DNA to avoid degradation.

Methylated DNA

DNA with added methyl groups at recognition sites.

Unmethylated DNA

DNA without methylation, susceptible to restriction enzymes.

Fungal Contaminant

Source of penicillin discovered accidentally.

Medical Problem

Antibiotic-resistant bacteria pose significant health risks.

Palindrome

Sequence reading same 5′-3′ on both strands.

Type II Restriction Enzymes

Most useful enzymes for genetic engineering.

Sticky Ends

Single-stranded overhangs after DNA cutting.

Blunt Ends

No overhangs; straight cuts in DNA.

Eco RI

Restriction enzyme producing sticky ends.

Eco RV

Restriction enzyme producing blunt ends.

BamHI

Restriction enzyme generating sticky ends.

Recombinant DNA

DNA fragments from different organisms combined.

DNA Ligase

Enzyme sealing DNA fragments together.

Hybridization

Temporary base pairing of complementary sequences.

Complete Digestion

Cutting DNA into smaller fragments using enzymes.

Fragment Size Estimation

Predicting sizes based on enzyme cutting frequency.

Single-Stranded DNA

DNA with unpaired bases after a cut.

Double-Stranded DNA

DNA with paired bases on both strands.

Genomic DNA

Total DNA content within an organism's cells.

Restriction Site

Specific location on DNA recognized by enzymes.

DNA Fragmentation

Process of cutting DNA into smaller pieces.

Temporary Base Pairing

Short-lived pairing of complementary DNA sequences.

Gene Isolation

Extracting specific genes from larger DNA fragments.

Molecular Cloning

Creating copies of DNA fragments using enzymes.

Gene Cloning

Process of creating copies of a specific gene.

Plasmid Vector

Circular DNA used to transfer genes into cells.

ori

Origin of replication in plasmid vectors.

Polylinker

Collection of unique restriction sites in vectors.

Reporter Gene

Gene used to indicate successful cloning.

Antibiotic Resistance Gene

Gene providing resistance to antibiotics for selection.

Transformation

Process of introducing DNA into bacterial cells.

Transduction

DNA transfer into bacteria via bacteriophages.

Cell Clones

Identical cells derived from a single original cell.

Amplification

Increasing the quantity of DNA through cloning.

Genomic Library

Collection of DNA fragments representing an organism's genome.

Restriction Enzymes

Enzymes that cut DNA at specific sequences.

Ligate

Joining DNA fragments together using ligase.

E. coli

Bacterium commonly used in genetic cloning.

DNA Insert

Foreign DNA incorporated into a plasmid vector.

Cloning Experiment

Initial experiment to produce recombinant DNA.

Recombinant Vector

Vector containing foreign DNA inserted into it.

DNA Sequencing

Determining the nucleotide sequence of DNA.

Promoter

Region of DNA initiating transcription of a gene.

Introns

Non-coding segments of DNA within a gene.

Coding Regions

Parts of DNA that encode proteins.

Culture Volume

Amount of liquid medium used for bacterial growth.

Transformed Cell

Cell that carries a piece of foreign DNA.

Restriction Endonuclease

Enzyme that cleaves DNA at specific sequences.

Recombinant Plasmid

Vector containing inserted DNA fragment.

E. coli Host Strain

Bacterial strain used for DNA transformation.

cDNA Library

Collection of cloned cDNA representing expressed genes.

Reverse Transcriptase

Enzyme that synthesizes DNA from RNA template.

Processed mRNA

mRNA that has undergone splicing to remove introns.

DNA Polymerase

Enzyme that synthesizes DNA strands from templates.

Double-stranded cDNA

cDNA formed by complementary DNA synthesis.

PCR (Polymerase Chain Reaction)

Technique to amplify specific DNA sequences.

Flanking Sequences

Nucleotide sequences surrounding the target DNA.

Contaminating DNA

Unwanted DNA that may interfere with PCR results.

Library of Genomic Clones

Collection of cloned genomic DNA fragments.

Active Protein Production

Expression of proteins from specific genes in cells.

cDNA Insertion

Process of inserting cDNA into a vector.

Gene Expression

Process by which genes are transcribed and translated.

Tissue Harvesting

Collection of specific tissues for mRNA isolation.

Vector

DNA molecule used to deliver genetic material.

Limitations of Genomic Library

Includes introns; not suitable for protein production.

Advantages of PCR

Fast, easy, and minimizes experimental variables.

Gel Electrophoresis

Technique to separate DNA fragments by size.

Dideoxy Chain Termination

Method for determining DNA sequences.

Transcriptome

Complete set of RNA transcripts in a cell.

Microarrays

Tools for analyzing gene expression levels.

CRISPR-Cas9

Genome editing tool using guide RNA.

sgRNA

Single guide RNA directs Cas9 to target DNA.

Natural Repair Systems

Cellular mechanisms to fix DNA breaks.

Gene Knockout

Disabling a gene to study its function.

Template Repair

Using a DNA copy to fix mutations.

Disease-causing Mutation

Genetic alteration leading to health issues.

Overactive Protein

Protein that functions excessively due to mutation.

Defective Protein

Non-functional protein resulting from genetic mutations.

Nobel Prize in Chemistry 2020

Awarded to Charpentier and Doudna for CRISPR.

Therapeutic Approaches

Strategies for treating genetic and chronic diseases.

Sickle-cell Anemia

Blood disorder caused by abnormal hemoglobin.

Thalassemia

Genetic blood disorder affecting hemoglobin production.

Leukemia

Cancer of blood-forming tissues, especially bone marrow.

Neurodegenerative Disorders

Conditions leading to progressive nerve cell degeneration.

Alzheimer's Disease

Progressive brain disorder affecting memory and cognition.