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Chapter 9 and 10. DNA: Genetic Material How Proteins are made. James Watson and Francis Crick. 1950’s Used past experiments done by other scientists Discovered the structure of DNA. Characteristics of DNA. Double Helix (twisted staircase). Nucleotides – make up DNA. Subunits
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Chapter 9 and 10 DNA: Genetic Material How Proteins are made
James Watson and Francis Crick • 1950’s • Used past experiments done by other scientists • Discovered the structure of DNA
Characteristics of DNA • Double Helix (twisted staircase)
Nucleotides – make up DNA • Subunits • Contain 3 parts: • A phosphate • A sugar- Deoxyribose • Nitrogen base • Adenine (A) • Guanine (G) • Thiamine (T) • Cytosine (C)
Nucleotide Pairing • http://www.phsuccessnet.com/iText/products/0-13-115075-8/index.html • Adenine pairs with thymine • Guanine pairs with cytosine
9-3 Replication of DNA • Occurs during what phase of cell cycle? • Steps: • 2 original DNA stands unzip • Free nucleotides in nucleus are added to each strand • Two identical molecules of DNA are formed.
Chapter 10: Making Proteins • What is RNA? • It is a copy of DNA • RNA is used to build proteins • Single stranded • No tymine
RNA nucleotides • Ribonucleic Acid • 3 parts: • Sugar: ribose • Single stranded • Nitrogen bases: • Adenine • URACIL • Cytosine • guanine
RNA pairings • Adenine pairs with Uracil • Cytosine pairs with Guanine
Types of RNA • mRNA – messenger RNA • Made in nucleus, strand shape
tRNA – transfer RNA • Found outside nucleus • Carries an amino acid
The cell’s alive, it will survive Transcription and translation are how proteins are synthesized Translation
Step 1 of Protein synthesis • Transcription – construction of mRNA • DNA strands separate a site of needed protein code. • RNA nucleotides are added to DNA. DNA acts as a template. • mRNA moves out of the nucleus into the cytoplasm to the ribosome
Step 2: Translation • At the ribosome: mRNA is read in groups of 3. • Codon – Group of 3 bases
Translation continued • mRNA is read and interpreted • tRNA receives a message to come to the mRNA at ribosome • tRNA carries an amino acid • (anticodon)
Translation • This continues until the mRNA is read completely • tRNA attaches to mRNA to attach the amino acid to the protein chain • tRNA them detaches leaving behind its amino acid. • Amino acid will form a protein.
Mutations • Changes in the DNA sequence that affect genetic information • Result from changes in a SINGLE gene (not chromosome abnormality)
Types of Gene mutations • 1. point mutation • One nucleotide affected • Examples: • Substitution • Original - The fat cat ate the wee rat. • Point Mutation - The fat hat ate the wee rat.
Types of Mutations • 2. Frameshift mutations – one or more bases are inserted or deleted • More severe type of mutation Insertion: • Original- The fat cat ate the wee rat. • Insertion - The fat cat xlw ate the wee rat. Deletion: • The fat cat ate the wee rat. • Deletion - The fat ate the wee rat.
Human Genome Project (Collins) • A list of the three billion pairs of human genome (DNA) • An international effort • Completed by the July of 2000 – “working draft” • Great implications in the field of medicine. (Cancer, Immune Disorders, Hemophilia, rheumatoid arthritis)
DNA Technology (Science) • Recombinant DNA technology – combining genes from two different organisms to make copies of “good” gene.
Steps of Recombinant DNA • Cutting DNA using a RESTRICTION ENZYME
2. Inserting the desired gene into a vector • Vector – a bacteria (plasmid) or yeast
Applications of Recombinant DNA • Agriculture – frost resistant strawberries • Industry – clean up oil spills • Medicine • Food industry – nutrasweet
DNA fingerprinting • Useful in forensic science • Useful in medicine
Future of medicine • predictive genetic tests for common conditions i.e. cancer • 2020, every tumor will undergo “fingerprinting”, develop drugs to attack the particular gene.