Genetics Test 3
Terms
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Name - Adenine
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Name - Cytosine
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Name - Guanine
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Name - Thymine
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Name - Uracil
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Name - 2'-deoxyribose
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Name linkage - Purine linkage (1-9 linkage)
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Name linkage - Pyrimidine Linkage (1-1 Linkage)
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Name - Ribose
- Nucleotide
- Unit structure of DNA. Composed of nitrogen base, sugar, and phosphoric acid
- Deoxyribonucleic Acid
- Chemical unit of heritable information
- Erwin Chargaff
- Base composition/ chemistry of DNA
- Tetranucleotide Hypothesis
- 4 bases are present in equal amounts. Tested by Chargaff
- Chargaff's Rules
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#A=#T, #G=#C
(A+G)=(T+C)
%(G+C)≠%(A+T) - Rosalind Franklin
- Used x-ray diffraction to obtain pictures of DNA molecule. Recognized DNA as helical
- Periodicity of DNA
- Bases are 3.4Ã… apart with 10 bases per turn.
- Model of DNA
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- Right handed helix
- 1 complete turn= 34Ã…
- Diameter= 20Ã…
- Space between pairs= 3.4Ã…
- 10 bases per turn
- Antiparallel
- Major and minor grooves alternate - Avery, Macleod, and McCarty
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-Made the TRANSFORMING PROPERTY- heritable properties are carried on DNA
-Used mice to show that DNA is capable of transformation - Hershey and Chase
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-DNA is the bio-molecule of heredity
-Used bacteriophage to show that DNA is genetic material
-Protein is not the genetic material - Watson and Crick
- Chemical components, physical structure, and molecular form of DNA
- Classic form of DNA
- Beta form
- DNA Sequencing
- The determination of the precise sequence of nucleotides in a sample of DNA
- Common method of DNA sequencing
- Chain termination
- Chain termination occurs with
- dideoxynucleotides
- Needed for DNA Sequencing
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1) ssDNA template
2) Primer
3) DNA polymerase
4) dNTP's
5) Appropriate dideoxynucleotides - Electrophoresis
- Uses electric field to seperate fragments based on size and length
- AZT
- Slows down replication
- Alpha form of DNA
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- High slat, dehydrated conditions
- More compact- 11 bp/turn
- 23Ã… diameter - Z form of DNA
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- Zig zag conformaion
- No major grooves
- Left handed helix - Function of DNA
- Genotype- form of genetic info
- Function of RNA
- Intermediate of phenotype, sometimes genotype
- Bases of DNA
- A=T, C=G
- Bases of RNA
- A=U, C=G
- Sugar of DNA
- 2' deoxyribose
- Sugar of RNA
- Ribose
- Unit structure of DNA
- Nucleotides
- Unit structure of RNA
- Nucleotides
- Gross structure of DNA
- Always double stranded helical
- Gross structure of RNA
- Generally single stranded linear, when genotype, can be double sranded helical
- Genome
- Total number of nucleotides present in an organism that constitutes genetic information; diploid content of genetic information
- Genome Complexity
- Organizaion of nucleotide; biological properties
- Genome Size
- Number of nucleotides
- Reassosciation Kinetics
- Isolate DNA -> Fragment into small peices -> Heat/Denature -> Cool/Renature -> Fragments reassociate by complimentarity
- Reassociation is dependent on
- Genome size and complexity
- Fast Reassosciation
- Short repetitive sequences
- Slow Reassociation
- Longer lengths of DNA with increased complexity
- Cot curve shape
- Genome Complexity
- Cot curve length
- Genome size
- Highly Repetitive DNA
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- Non-coding
- Rapid reassociation
- 5-10 bp in length
- 5-10% of genome
- Around centromeres and telomeres
- Maintains chromosome morphology - Moderately Repetitive DNA
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- Non-coding
- 150-500 bp in length
- 5-10% of genome
- Repeated 700-900,000 times
- Non coding- mutation buffers - Unique DNA
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- Coding- genotype
- 1,000-15,000 bp in length
- 35,000 genes in humans
- 1-5% of total nucleotides - C-value
- The amount of DNA contained in the haploid genome of a species
- C-value Paradox
- Excess DNA is present that does not seem to be essential to the development or evolutionary divergence of eukaryotes
- G2 Phase
- Cells prepare for division
- G1 Phase
- Cells sit- DNA is stringy
- S/R Phase
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- DNA makes copies and sister chromatids
- DNA synthesis and replication - M Phase
- Mitosis
- Semi-conservative Replication
- Watson and Crick proposed form. Following synthesis of the new strands, each parent strand links with a new strand in complimentary fashion
- Conservative Replication
- Synthesis follows Watson and Crick's model however by some mechanism, each parental strand reforms together while the 2 new strands also link together
- Dispersive Replication
- Each parental strand goes through a cleavage process followed by reforming of all strands together
- Replicated Homologs
- Sister chromatids
- Replicon
- Site of replication
- Arthur Kornberg
- DNA is universal/ highly conserved
- Replication always occurs in which direction?
- 5' -> 3'
- DNA Gyrase
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- Member of the family of topoisomerases
- Reduces super-cooling of DNA - Helicase
- Opens DNA strands making them ssDNA
- Primase
- Lays down an RNA primer
- DNA Polymerase
- Binds RNA primer at 3' OH and makes new strands
- Ligase
- Joins together the newly synthesized strands of DNA by sealing the phosphodiester bonds
- Telomerase
- Fills in any gaps created at tips of the 3' ends in the old DNA strand
- DNA Replication
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1) Helicase binds to DNA strands and pull them apart
2) Primase recognizes origin points, binds to ssDNA, lays down RNA primer
3) Synthesis in 5' -> 3' direction
4) DNA pol removes primers and replaces them with DNA
5) Ligase fills gaps between fragments
6) Telomerase binds at 3' end to remove unmatched pairs