Fundamentals of Molecular Biology
DNA : The Molecule of Heredity
Genes, and DNA, Expression of Genetic Information
Recombinant DNA, Detection of Nucleic Acids and Proteins
Gene Function in Eukaryotes
, Key Experiment: The DNA Provirus HypothesisMolecular Medicine: HIV and AIDS
Genetic traits can be altered by treatment with pure DNA
Transmission of DNA is the link between generations
The DNA Structure is a Double Helix Composed of Two Intertwined Strands
In DNA Replication, Each Parental DNA Strand (Template strand) Directs the Synthesis of a New Partner Strand along the old strand
:Semi-conservative Replication
Genes Code for Proteins:
Defects in Enzyme structure result in inborn errors of metabolism ; defective enzyme results from a mutant gene, One of the DNA strands of the double-helix directs the synthesis of a RNA molecule, A RNA molecule directs the synthesis of a polypeptide chain , The genetic code called a codon is a triplet code (three consecutive base on a DNA strand)
Mutation Change Genes
Traits Are Affected by Environments as Well as by Genes
Maternal PKU illustrates the importance role of genes and environment
Continuity of Life with Change Over Time Means Evolution:
Unity of life forms at the molecular level results from common ancestry. Natural selection. The diversity of life results mainly from the process of natural selection.THE CHEMICAL STRUCTURE AND REPLICATION OF DNA
Complex Organisms Generally Have Large Genomes
DNA Is a Linear Polymer of Four Deoxyribonucleotides
Duplex DNA forms a Double Helix Held Together by Hydrogen Bonds
Replication Uses Each DNA Strand as a Template for a New One
Nucleotides are added one at a time to the growing end of a DNA strand
DNA replication is semiconservative: The parental strands remain intact
DNA strands must unwind to be replicated
Eukaryotic DNA molecules contain multiple origins of replication
DNA Polymerase Makes the New DNA Strands
One strand of replicating DNA is synthesized in pieces
DNA is synthesized only in the 5' - 3' direction
Each new DNA strand or fragment is initiated by a short RNA primer
Precursor fragments are joined together when they meet
Many proteins participate in DNA replication
Knowledge of DNA Structure Makes Possible the Manipulation of DNA Molecules
Single strands of DNA or RNA with complementary sequences can hybridize
Restriction enzymes cleave duplex DNA at particular nucleotide sequences
Gel electrophoresis separates DNA fragments by size
Specific DNA fragments are identified by hybridization with a probe
The Polymerase Chain Reaction Makes Possible the Amplification of a Particular DNA Fragment
Chemical Terminators of DNA Synthesis Are Used to Determine the Base Sequence
The incorporation of a dideoxynucleotide terminates strand elongation
Automated DNA sequencing enables whole genomes to be analyzed
Dideoxynucleotide analogs are also used in the treatment of diseases
THE GENETICS OF BACTERIA AND VIRUSES
Much of Our Understanding of Molecular Genetics Comes from Bacteria and Bacteriophages
Transformation Results from the Uptake of DNA and Recombination
In Bacterial Conjugation, DNA Transfer is Unidirectional
A plasmid is an accessory DNA molecule, usually a circle
The F plasmid can integrate into the bacterial chromosome
Chromosome transfer begins at F and proceeds in one direction
Some F plasmids carry bacterial genes
Some Phages Can Transfer Small Pieces of Bacterial DNA
Bacteriophage DNA Molecules in the Same Cell Can Recombine
Bacteriophages form plaques on a lawn of bacteria
Infection with two mutant bacteriophages yields recombinant progeny
Genes are clustered by function in many bacteriophages
Recombination occurs within genes
Lysogenic Bacteriophages Do Not Necessarily Kill the Host
Specialized transducing phages carry a restricted set of bacterial genes
Bacterial Cells Contain Transposable Elements
GENE EXPRESSION
Polypeptide Chains Are Linear Polymers of Amino Acids
The Linear Order of Amino Acids Is Encoded in a DNA Base Sequence
The Base Sequence in DNA Specifies the Base Sequence in an RNA Transcript
The chemical synthesis of RNA is similar to that of DNA
Particular nucleotide sequences define the beginning and end of a gene
Messenger RNA directs the synthesis of a polypeptide chain
RNA Processing Converts the Orginal RNA Transcript into Messenger RNA
Splicing removes introns from the RNA transcript
Many exons code for distinct protein-folding domains
Translation into a Polypeptide Chain Takes Place on a Ribosome
Selection of the initiation codon differs in prokaryotes and eukaryotes
The Genetic Code for Amino Acids Is a Triplet Code
Genetic evidence for a triplet code came from three - base insertions and deletions
Most of the codons were determined from in vitro poypeptide synthesis
Redundancy and near - universality are principal features of the genetic code
An aminoacyl - RNA synthetase attaches an amino acid to its tRNA
Much of the code's redundancy comes from wobble in codon - anticodon pairing
More than one polypeptide can be translated from a messenger RNA in prokaryotes
Genes can sometimes overlap
GENETIC ENGINEERING AND GENOME ANALYSIS
Cloning a DNA Molecule Takes Place in Several Steps
Restrictions enzymes cleave DNA into fragments with defined ends
Restriction fragments are joined end to end to produce recombinant DNA
A vector is a carrier for recombinant DNA
A variety of strategies can be used to clone a gene
DNA fragments are joined with DNA ligase
A recombinant cDNA contains the coding sequence of a eukaryotic gene
Loss of B - galactosidase activity is often used to detect recombinant vectors
Recombinant clones are often identified by hybridization with a labeled probe
Positional Cloning Is Based on the Location of a Gene in the Genetic Map
Close genetic linkages are often conserved among related species
Reverse Genetics Creates an Organism with a Designed Mutation
Recombinant DNA can be introduced into the germ line of animals
Recombinant DNA can also be introduced into plant genomes
Genetic Engineering Is Applied in Agriculture, Industry, Medicine, and Research
Agricultural corp plants are primary targets of genetic engineering
Specific plant tissues can be targeted for self - destruction
Animal growth rate can be genetically engineered
Engineered microbes can help in the degradation of toxic waste
Recombinant DNA permeates modern biomedical research
The production of useful proteins is a primary impetus for recombinant DNA
Animal viruses may prove useful vectors for gene therapy
Recombinant DNA yields probes for the detection of mutant genes in hereditary disease
An Entire Genome Can Be Physically Mapped and Its DNA Sequence Determined
The smallest complex genomes are about 100 million base pairs
Special conditions allow production and isolation of large DNA fragments
Artificial chromosomes are vectors for large DNA fragments
The landmarks in physical maps range from chromosome bands to DNA sequences
Many Large - Scale DNA Sequencing Projects Are Under Way
The complete sequence of the E.coli genome is known
The yeast genome was the first eukaryotic genome sequenced
The target date for completion of the human genome sequence is 2005
DNA Sequencing Is Highly Automated