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Chapter 12: From Genes to Proteins. Traits, such as eye color, are determined by proteins that are built according to an organism’s DNA Proteins are made by decoding the information in DNA DNA and RNA work together to build proteins. DNA Double Stranded Deoxyribose
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Chapter 12: From Genes to Proteins • Traits, such as eye color, are determined by proteins that are built according to an organism’s DNA • Proteins are made by decoding the information in DNA • DNA and RNA work together to build proteins
DNA Double Stranded Deoxyribose Nitrogen bases (A, T, C, and G) Found only in the nucleus RNA Single stranded Ribose Nitrogen bases (A, Uracil, C and G) Found both in nucleus and cytoplasm Differences in DNA and RNA
Transcription Occurs in the Nucleus • Enzymes make an RNA copy of a DNA strand similar to DNA Replication; however, only (1) strand is made of RNA rather than (2) as in DNA.
mRNA- Messenger RNA is the RNA copy that leaves the nucleus and goes to a ribosome • Codon- set of 3 nitrogen bases that represent an amino acid (aa). • There are 20 known amino acids and 64 different codons (p. 303) • Of these sixty-four, sixty code for amino acids and the remaining 4 are “start” and “stop” signals.
Translation Occurs at the Ribosome • Translation is the process of converting the information in a sequence of mRNA into a sequence of amino acids that make up a protein. • tRNA (transfer RNA)- molecule that brings amino acids to the ribosomes so they can be made into chains of protein. • Anticodon- a set of 3 nitrogen bases (codon) is attached to each tRNA molecule.