Inheritance
Its in the blood"
- DNA mediates
- The acquisition of characteristics, qualities or traits by the transmission of genes from parent to offspring.
Prokaryotic
Contain one continuous space in which cellular materials are organized, but separated by membranes.
- All have cell walls
- Lack nucleus -- has nucleoid
- Usually single-celled
- Include both bacteria and archaea --> (live in extreme environments)
Eukaryotic
Contain sub-cellular compartments. A membrane surrounds each compartment.
- Usually 10-100 fold larger than prokaryotic cells
- Both single celled and multi-cellular organisims
- Plants are only surrounded by a cell wall
- contains nucleus and organelles
Organelles
Membrane bound compartments with distinctive morphology and function present in the cytoplasm of all eukaryotic cells
Nucleus
Home to the vast majority of DNA, where it is complexed with proteins and enclosed within a double membrane (nuclear envelope) and contains all the chromosomes and one or more nucleoli (site of ribosome assembly)
Nucleoid
A prokaryotes DNA is tightly coiled with proteins in this region and is not membrane bound.
Ribosomes
Very large multi-protein-RNA complexes that perform protein synthesis (translation) in the cell.
- Both eukaryotic and prokaryotes have
Cytoplasm
The watery interior environment of cell.
Traits
Genetically determined chacteristics and phenotypes exhibited by an individual
Dominance
A gene that directs a phenotype even when present at only one copy per cell
Recessive
Phenotypic expression of a genetic allele only in homozygous cells that lack wildtype forms of the gene.
Genes
Biological genetic units of heredity
Chromosomes
colored bodies"
Threadlike strands of chemical material located in the cell of nucleus.
- Structures in the cell nucleus that each contain one linear double-stranded DNA molecule.
Deoxynucleic acid (DNA)
Nucleic acid polymer of bases which make up the genes.
- First named nuclein
Zygote
The cell resulting from the union of a male and a female gamete during fertilization
Transforming substance
In early experiments, DNA was found to change (transform) the biochemistry of bacterial cells
Cell-free extract
Subcellular fraction created in vitro that retains biological activity.
Enzyme
A protein that acts as a catalyst, increasing the rate at which a chemical reaction occurs, without itself changing in molecular shape.
Segregation- Mendel
two alleles for a single trait separate during gamete formation
Independent assortment- Mendel
different traits are inherited separately
Dominance - Mendel
one allele can mask another
Wrinkled vs. Smooth seeds
insertion mutation- gene for starch synthesis- chromosome 5
Yellow vs. Green seeds
insertion or substitution- 'stay-green' gene (activates chlorophyll breakdown)- chromosome 1
Flower color (seed coat color)
intron-splicing mutation- transcription factor controlling a gene for anthocyanin synthesis- chromosome 2
Tall vs. Short plants
insertion- gene for gibberellin synthesis (a hormone that makes plants grow taller)- chromosome 3
Green vs. Yellow Pods
2 loci- linked traits- chromosome 5
Gregor Mendel
Developed the basic principles of genetics
Thomas Hunt Morgan
Showed that inheritance is due to chromosomes
Miescher/Feulgen/ Mirsky
Showed that inheritance is due to the DNA (not protein) in chromosomes
Griffith/Alloway/Avery
Showed that functional DNA could be extracted from one bacteria and placed into another bacteria
Hershey/Chase
Showed that DNA is responsible for viral replication.
DNA Polymerase
An enzyme that copies DNA templates into new DNA strands when chromosomes are being replicated
Primers
A short RNA or DNA strand that is base paired to the template DNA strand at the position on the helix where DNA replication takes place.
DNA ligase
Enzyme that catalyzes the formation of a covalent chemical bond between the 3' and 5' ends of two DNA strands, sealing the DNA backbone and joining DNA fragments end to end.
3' to 5' proofreading exonuclease
Enzymes that cleave single mononucleotides from the 5' to 3' end of the DNA strand
Orgin of Replication
Site on a DNA molecule where DNA replication begins (initiation)
Nanotechnology
Technology dealing with structures smaller than 100 nanometers in size and involves developing materials or devices with novel properties; the technology of molecular manufacturing outside the cell, including molecular machinery inside the cell.
Bases
Alkaline chemical substances; in molecular biology refers to the cyclic nitrogen compounds found in DNA and RNA.
Adenine
A PURINE base found in the DNA and RNA nucleic acids of cells in plant and animal cells.
Thymine
A PYRIMIDINE base found in DNA but... NOT RNA
Guanine
One of the five fundamental bases that make up DNA and RNA sequences. PURINE
Cytosine
a PYRIMIDINE base in DNA and RNA
Uracil
A PYRIMIDINE base found in RNA but.. NOT DNA
Purines
heterocyclic aromatic organic molecule
Pyrimidines
Type of nitrogenous base with a single chemical ring found in DNA and RNA
Nucleotides
The monomer component of a nucleic acid (DNA or RNA), consisting of a PENTOSE sugar plus a base and a phosphate group.
Polarity
In DNA this refers to the two chemically different ends of each DNA strand called 3' and 5'.
In the helix, the two DNA strands are arranged in opposite directions: 5' to 3' and 3' to 5'.
In cell development, polarity can refer to the different biological
Antiparallel
DNA strands with polarity (5' to 3') are arranged in opposite directions in the DNA helix molecule.
5' to 3' direction
Starting at 5' end of a DNA strand and reading toward the 3' end of the same DNA strand.
X-ray diffraction
A process in which crystallized molecules are rotated and bombarded with x-rays to determine structural information about the molecule.
Transcription
Process by which genetic information in DNA is copied into an RNA transcript.
E. coli DNA Polymerase I
one of three enzymes that replicate DNA in E. coli
Monomer
A protein molecule of a relatively low molecular weight that can bind to itself and other proteins to form dimers, trimers, or other protein complexes, sometimes bound to DNA or RNA.
Multiprotein
Consisting of several proteins that interact together in a complex.
Replication fork
The region of a replicating DNA that encompases half of a replication bubble
- Contains replicating DNA and the enzymes and other proteins involved in DNA synthesis.
Leading strand
The strand of DNA that is synthesized continuously during DNA replication and DOES NOT contain Okazaki fragments.
Lagging strand
The DNA synthesized in short single-strands called Okazaki fragments during discontinuous DNA replication.
Helicase
An enzyme that unwinds the DNA double helix at each replication fork
Continuous replication
mechanism of DNA replication used to synthesize the leading strand of DNA at each replication fork
Discontinuous replication
mechanism of DNA replication used to synthesize the lagging strand of DNA at each replication fork
Primase
Enzyme that participates in DNA replication by making RNA primers needed to initiate DNA replication.
Okazaki fragments
short single-stranded DNA synthesized on the lagging strand during DNA replication
Origin of replication
short DNA sequences where proteins help to unwind the double-helix
Molecular structure of DNA
5' --> 3', sugar phosphate backbone with phosphodiester bond, 5' end is nonpolar with phosphate group exposed, 3' end is polar with exposed hydroxyl group for next base to attach to, A and T two hydrogen bonds, C and G three hydrogen bonds
How do you recognize individual DNA nucleotides that combine to form a longer DNA molecule
pentose 5C sugar with -OH at carbon 3
Phoebus Levene
Described the chemical 'building blocks' of DNA and RNA
Erwin Chargaff
Discovered that the amount of adenine in DNA was equivalent to the amount of Thymine and the amount of cytosine was equivalent to the amount of guanine
Rosalind Franklin
Performed crystallography and x-ray diffraction of DNA
Watson/Crick
Determined the 3-D structure of DNA
Meselson/Stahl
Showed that during DNA replication, both original strands serve as templates for making new strands. (Semi-conservative replication)
Arthur Kornberg
Isolated functional DNA polymerase from bacteria
DNA replication
5' to 3' direction, DNA polymerase, DNA ligase
Figure 2.26
DNA --> RNA --> protein
Genetic Screen
A method to search for rare cells using the genetic characteristics of the cells.
Mutation
Change in a DNA or RNA sequence
Mutagen
An agent that induces genetic mutation by changing DNA sequence.
(For ex: a "G" changed to a "T")
One gene-one enzyme hypothesis
The early idea that each gene in a cell can produce only one specific protein or cellular enzyme.
Amino acid
any of a class of organic compounds containing amino (NH2) and the carboxyl (COOH) groups, forming the main constituents of protein
Protein synthesis
The production of proteins by the process of TRANSLATION in cells.
Codons
3 consecutive RNA or DNA bases that encode a single amino acid
Genetic Code
The sequence of tandem nucleotide triplets (codons) in DNA or RNA that specifies the aa sequence of a protein.
Central Dogma
DNA --> Transcription --> RNA --> Translation --> Protein
Beadle/Tatum
wanted to induce mutations that affect its ability to make essential vitamins or amino acids, used x-rays. Then grew it on enriched media which includes all vitamins and amino acids that it would need. E2 is not functional
Single mutation leading to sickle cell anemia
146th amino acid is changed from glutamic acid (normal) to valine (mutant)
Bacteriophage
viruses that infect bacterial cells
How does bacteriophage reproduce?
DNA genomes enter the cells, the bacteria synthesize the bacteriophage RNA before they begin synthesizing protein
Figure 3.17
genetic code table- first, second, and third bases in codon make a single protein
How is protein sequence determined from DNA sequence?
3 consecutive RNA bases encode a single amino acid which together form a protein linked with a peptide bond