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Section 4 Protein Synthesis. What is the importance of synthesizing protein?. Our hair, skin, nails, muscle fibers, and enzymes are made of protein. Proteins protect us from infections and allow our blood to carry oxygen. Transcription.
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What is the importance of synthesizing protein? • Our hair, skin, nails, muscle fibers, and enzymes are made of protein. • Proteins protect us from infections and allow our blood to carry oxygen.
Transcription • The process of making an mRNA strand using the DNA in the nucleus as a template
Differences between DNA and RNA DNA RNA • Double-stranded • Thymine nitrogen base, not uracil • Sugar; dexoyribose • Longer • Single-stranded • Uracil nitrogen base, not thymine • Sugar; ribose • Shorter • *3 types of RNA
Steps of transcription: RNA polymerase attaches to DNA causing the DNA strands to unwind and separate RNA polymerase adds free nucleotide s to one side of the DNA molecule If DNA reads… GGCTATACGTAC What would the mRNA read? 3) RNA polymerase reaches a termination signal to stop trancription and RNA and DNA are released from the polymerase
The Genetic Code -the term for the rules that relate how a sequence of nitrogen bases in nucleotides corresponds to a particular amino acid, Every 3 letters of mRNA is called a codon.
Each codon “codes” for a certain amino acidEx. GGU CUA GGU = glycine CUA = leucine
Translation The making of a protein in the ribosomes from mRNA.
tRNA • Has a 3-letter anti-codon on one end and is attached to an amino acid on the other • Brings the amino acid to the ribosome where it is attached to another amino acid by a peptide bond