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DNA/RNA DNA/RNA
DNA/RNADNA/RNA
Every new cell that develops in your Every new cell that develops in your body needs an exact copy of the body needs an exact copy of the DNADNA from the from the parent cellparent cell. All . All organisms must be able to pass organisms must be able to pass copies of their DNA on to their copies of their DNA on to their offspring in order to offspring in order to continue the continue the speciesspecies. .
1.1. To store & use information, to To store & use information, to direct activities of the celldirect activities of the cell
2.2. To copy itself exactly for new To copy itself exactly for new cells that are createdcells that are created..
• DNA and RNA are DNA and RNA are polymerspolymers (repeating subunits) of (repeating subunits) of nucleotidesnucleotides. DNA is made of . DNA is made of two long strands, in the shape two long strands, in the shape of a of a double helixdouble helix or twisted or twisted ladder, of a chain of ladder, of a chain of nucleotides.nucleotides.
• Deoxyribose (a five carbon Deoxyribose (a five carbon sugar) (s)sugar) (s)
• A phosphate group (pA phosphate group (p) )
• A nitrogen base (G, C, A, T)A nitrogen base (G, C, A, T)
1.1. AdenineAdenine
2.2. GuanineGuanine
3.3. ThymineThymine
4.4. CytosineCytosine
•““A” Always goes with A” Always goes with “T”“T” (held together by (held together by 2 2 hydrogenhydrogen bonds) bonds)
•““G” always goes with G” always goes with “C”“C” (held together by (held together by 3 3 hydrogenhydrogen bonds) bonds)
• Adenine and Guanine are Purines Adenine and Guanine are Purines ((doubledouble rings of carbon) rings of carbon)
• Thymine and Cytosine are Thymine and Cytosine are Pyrimidines (Pyrimidines (single single ring of carbon)ring of carbon)
• In 1953 two scientists In 1953 two scientists figured the shape of figured the shape of the DNA molecule was the DNA molecule was a double helix: a double helix:
James WatsonJames Watson (currently participating (currently participating in the in the Human Genome Human Genome ProjectProject in CA) & in CA) &
Francis CrickFrancis Crick. . Rosalind FranklinRosalind Franklin also also
helpedhelped..
• DNA makes DNADNA makes DNA, this , this happens in happens in interphaseinterphase • This is the process of This is the process of
DNA duplication. The DNA duplication. The strand strand unzips unzips along along thethe hydrogen hydrogen bonds, bonds, then the then the complimentary complimentary nucleotide attaches to nucleotide attaches to the missing partthe missing part..
Original Strand
New Strand
*Adenine can only bond w/ *Adenine can only bond w/ Thymine,Thymine, while Cytosine can only bond w/ while Cytosine can only bond w/ Guanine.Guanine.
What would the What would the complimentarycomplimentary strand look like?strand look like?
CC GG AA TT TT AA CC GG TT
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• RNA or RNA or Ribonucleic acidRibonucleic acid has the primary has the primary function of function of synthesizing synthesizing proteinsproteins & is & is made from DNAmade from DNA..
1) RNA has only 1) RNA has only one strand one strand of nucleotidesof nucleotides instead of instead of twotwo
2) RNA has 2) RNA has riboseribose as its as its sugar base instead of sugar base instead of deoxyribosedeoxyribose
3) RNA has the nitrogen base 3) RNA has the nitrogen base URACIL URACIL instead of Thymineinstead of Thymine
RNA is different from DNA in 3 ways!!!!
1.1. Messenger RNAMessenger RNA or mRNA it serves as or mRNA it serves as a template for the assembly of amino a template for the assembly of amino acids when proteins are madeacids when proteins are made
2. 2. Transfer RNATransfer RNA or tRNA it is a or tRNA it is a folded back folded back strand & can strand & can exist in 20 or exist in 20 or more varieties, more varieties, each bonding to each bonding to only one specific only one specific amino acidamino acid
• Ribosomal Ribosomal RNARNA or rRNA or rRNA is the glob-is the glob-shaped form shaped form found on the found on the ribosome. It ribosome. It assembles the assembles the amino acids in amino acids in the correct the correct orderorder. .
• DNA makes mRNADNA makes mRNA
• RNA is produced from DNA through this RNA is produced from DNA through this process.process.
• TranscriptionTranscription means “to write across” means “to write across”
• A group of A group of 33 sequential bases of mRNA sequential bases of mRNA is called a is called a codoncodon..
• A list of all 64 possible amino acids A list of all 64 possible amino acids codons can be found in your textbook. codons can be found in your textbook.
• protein synthesisprotein synthesis
• Translation takes place in the Translation takes place in the cytoplasm!cytoplasm!
• It is the process in which It is the process in which mRNA mRNA attaches attaches to a to a ribosomeribosome; tRNA which carries a ; tRNA which carries a specific specific amino acidamino acid attaches its attaches its anticodonanticodon to the correct mRNA to the correct mRNA codoncodon building a building a chain of amino acids which codes for a chain of amino acids which codes for a specific proteinspecific protein..
• A protein may consist of hundreds or A protein may consist of hundreds or thousands of amino acids which codes for thousands of amino acids which codes for a specific protein, & all these amino acids a specific protein, & all these amino acids must be arranged in a particular sequence must be arranged in a particular sequence for for the protein to function properlythe protein to function properly
• A codon A codon sequence of sequence of AUG GCU UCC AUG GCU UCC GGU would GGU would code for what code for what amino acid?amino acid?
• If Glumatic acid is If Glumatic acid is GAG, a mutation GAG, a mutation of its third base of its third base would result in a would result in a codon for which codon for which amino acid?amino acid?
Met-Ala-Pro-GlyMet-Ala-Pro-Gly Possibly Aspartic acidPossibly Aspartic acid
• An amino acid An amino acid sequence of sequence of Alanine-Histine-Alanine-Histine-Arginine would Arginine would have which have which codon sequence?codon sequence?
• Given the codon Given the codon sequence UGG sequence UGG what amino acid what amino acid will be will be produced?produced?
GCU-CAU-CGGTryptophan
DNA: TAC-AGT-GTG-TTA-ATC
**mRNA:*tRNA:amino acids:
12.4 DNA part 2 Notes
•Mutation in reproductive cells are changes on the sequence of nucleotides with a gene in a sperm or egg cell; when these cells take part in fertilization the changed gene would be a part of the genetic makeup of the offspring
•Mutations in body cells. EX: Skin, muscle; may cause problems for the individual but would not be passed on to offspring.
•Mutagens any agent that can cause a change in DNA; some examples are high energy radiation, chemicals, and even high temperatures
•Point mutations – any change in a single base in DNA; might affect the structure of a protein (Ex: sickle cell)
•Frame shift mutation - where a single base is added or deleted
•occurs in all living organisms, more common in plants formed when parts of chromosomes are broken off and lost during meiosis or mitosis; •caused by nondisjuntion
•Deletion – part of a chromosome is left out• Insertions – part of chromatid breaks off and attaches to its sister chromatid duplication of genes• Inversion – a part of a chromosome breaks off and is reinserted backwards•Translocation – part of one chromosome breaks off and is added to a different chromosome
•Enzyme proofread the DNA and replace incorrect nucleotides with correct nucleotide; •not perfect the greater the exposure to a mutagen the more likely a mistake will not be corrected
DNA notes part 3
•For thousands of years people have tried to produce plants and animals with desirable traits
1)Selective Breeding – a process of selecting a few organisms with desired traits to serve as parents of the next generation
• EX: Cows that produce more milk, vegetables that resist disease
1.Inbreeding – crossing 2 individuals with similar sets of genes to produce specific traits (may lead to genetic disorders)
2.Hybridization – crossing 2 genetically different individuals to have the best of both parents
2) Cloning – producing organisms that are genetically identical to the organism form which it was produced
• 3) Genetic Engineering (Recombinant DNA) – genes from one organism are transferred into the DNA of another organism,• used to produce medicine, improve food crops and help cure human genetic disorders (such as insulin, Human Growth Hormone, Factor VIII (protein in hemophiliacs)
1) Isolate- using restrictive enzymes to cleave (cut) the foreign DNA fragment to be inserted.
Use the Restrictive Enzymes Hae III and EcoRI to cut the DNA below:
Hae III=CCGG EcoRI=GAATTC (palindrome)
GGCC CTTAAG
2)Attach the DNA fragment to a “vehicle” or vector
3)Transfer the vehicle into the host (recipient) organism
•Plasmids- small rings of DNA found only in bacterial cells•Gene splicing- rejoining of DNA fragments•Transgenic Organism- organism that contains the foreign DNA
• Vectors (vehicles)- may be biological or mechanical • *Biological Vectors: viruses and Plasmids • *Mechanical Vectors: micropipette and tiny metal bullets • Polymerase Chain Reaction (PCR) is a technique where millions of copies of tiny DNA fragments are cloned in hours.
• Human Genome Project- is an international effort to completely map and sequence the approximately 100,000 genes on the 46 human chromosomes • Linkage Maps are used to show
the location of genes on the chromosomes.
• Diagnosis of Genetic Disorders- uses amniocentesis and karyotypes • Gene Therapy- normal genes are inserted into human cells
• DNA Fingerprinting- DNA (genes) patterns are used to determine genetic disorders, solve parentage disputes, and crimes (DNA can be derived from blood, skin, semen, saliva, etc.)–Electrophoresis- techniques used to create a DNA fingerprint DNA is placed into a gel and an electric voltage is applied pulling the negatively charged DNA fragments toward the positive end of the gel; creates unique DNA patterns.
• Which couple does Baby 1 belong to? Steventon Baby 2? Jones Baby 3? Smith
