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Inheritance and the Structure of DNA. Deoxyribonucleic Acid. DNA Discovery. 1928 -Frederick Griffith transforming factor 1944 -James Watson and Francis Crick discovered that DNA was the transforming factor 1952 -Rosalind Franklin and Maurice Wilkins
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DNA Discovery • 1928-Frederick Griffith • transforming factor • 1944-James Watson and Francis Crick • discovered that DNA was the transforming factor • 1952-Rosalind Franklin and Maurice Wilkins • took x-ray photographs of the DNA molecule • 1953-Watson and Crick • created a three-dimensional 3-D model of DNA • 1962-Watson, Crick, and Wilkins • received the Nobel Prize in Medicine
What is DNA? • Genetic material used to express traits • Nucleotide units • Deoxyribose (sugar) • Phosphate • Base • Purines (double ring) • Thymine ( T ) • Cytosine ( C ) • Pyrimidine (one ring) • Adenine ( A ) • Guanine ( G )
Complementary Strands • Order of bases on the nucleotides in one strand of DNA complements the order of bases on the opposite strand • base sequence
DNA Replication • DNA stores and transmit information that tells cells which proteins to make and when to make them. • DNA located in the nucleus and cannot leave. • Duplication of DNA
RNA (Ribonucleic Acid) • RNA differs from DNA • Sugar is ribose • The nitrogen base THYMINE is replaced by URACIL • RNA is single-stranded • There are three types of RNA • Messenger RNA (mRNA) • Transfer RNA (tRNA) • Ribosomal RNA (rRNA)
RNA • Messenger RNA (mRNA) • copies the information from the DNA in the nucleus • Transfer RNA (tRNA) • reads the information from mRNA • carries amino acids to the ribosome • Ribosomal RNA (rRNA)
Transcription • DNA to mRNA • in nucleus • Translation • mRNA to tRNA and rRNA to make proteins • in cytoplasm
Transcription • Reading the gene • RNA polymerase (mRNA)
Translation • RNA to proteins • Cytoplasm • tRNA, rRNA, and mRNA • assemble proteins • Genetic Code • Three letter word (codon) • Codon codes for amino acid • 64 mRNA
Translation • Specific amino acid on one end of each tRNA. • anticodon on tRNA is complementary codon on mRNA. • mRNA joins with a rRNA and tRNA • first tRNA is released from the ribosome • Amino acids bond creating a polypeptide chain • This process is repeated until one of three stop codons is reached