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RNA, DNA, and Protein Synthesis. Deoxyribonucleic Acid (DNA). A double stranded molecule containing genetic material that carries all the information about an organism and is passed from parent to offspring. Nucleotides (building blocks of DNA). Nitrogen Base. Sugar Phosphate group
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Deoxyribonucleic Acid (DNA) A double stranded molecule containing genetic material that carries all the information about an organism and is passed from parent to offspring.
Nucleotides (building blocks of DNA) Nitrogen Base • Sugar • Phosphate group • Nitrogenous base Lll DNA Nucleotide Phosphate Sugar
Nitrogen Bases The 4 nitrogen bases in DNA are: • adenine, • guanine, • cytosine, and • thymine.
The Structure of DNA Rosalind Franklin Used X-Ray crystallography to get information about the structure of DNA.
Structure of DNA Using Rosalind Franklin’s data, two scientists: • James Watson (USA) • Francis Crick (GBR) Proposed that DNA was a double-helix. Watson & Crick along with Maurice Wilkins jointly received the Nobel Prize in physiology or medicine for their work.
The Double-Helix A twisted ladder with two long chains of alternating phosphates and sugars. The nitrogen bases act as the “rungs” joining the two strands.
Chromosome Structure: Chromosomes are complexes of DNA wound around proteins (called histones) residing in the nucleus of the cell. Genes are sections of DNA that code for a specific protein that determines a particular characteristic.
Ribonucleic Acid (RNA) RNA is similar to DNA in that it is also a nucleic acid composed of 4 nucleotides. Ways RNA is different from DNA: • RNA contains Ribose, a 5-carbon sugar (instead of deoxyribose) • Uracil replaces thymine • Single-stranded
Messenger RNA (mRNA) • Copies a section of DNA by matching bases. • Contains the instructions (recipe) for producing a specific protein.
TRANSCRIPTION • The process of copying information from a section of DNA into mRNA. • Transcription is like copying down a recipe. In this case it’s a recipe for a specific protein.
TRANSLATION • Translation = reading or “translating” the RNA code to form a chain of amino acids. • Results in protein synthesis • Occurs in the cytoplasm.
Transfer RNA (tRNA) • tRNA acts like a truck to transport an amino acid to the ribosome to make the specific protein coded by the mRNA. • A specific amino acid is attached to one end.
The Genetic Code The genetic code is responsible for building all the proteins in the body using 20 different amino acids. Amino acids Protein molecule
The genetic code is the “language” that translates the sequence of nitrogen bases in DNA (mRNA) into the amino acids of a protein. • Codon = three nucleotides on DNA or mRNA • One codon specifies one amino acid • Some codons are redundant (code for the same amino acid) • The genetic code is universal to all organisms
Codon: A three letter “word” (sequence of RNA nucleotides) that specifies an amino acid.
DNA: TAC CTT GTG CAT GGG ATC mRNA AUG GAA CAC GUA CCC UAG A.A MET G.A HIS VAL PRO STOP