Protein Synthesis Notes PDF

Protein Synthesis By the end of this lesson, you will be able to: Contrast the locations of transcription and translation. Describe the steps of transcription and translation. If given a DNA strand, be able to transcribe and translate it so that the...

Protein Synthesis By the end of this lesson, you will be able to: Contrast the locations of transcription and translation. Describe the steps of transcription and translation. If given a DNA strand, be able to transcribe and translate it so that the correct protein is made. Contrast DNA with RNA. Protein Synthesis: 2 part process= 1.Transcription 2. Translation 5 min intro video Transcription→ Making mRNA from DNA Takes place in the nucleus Transcription Steps: (1) DNA “unzips” – RNA polymerase breaks hydrogen bonds between base pairs (2) Free-floating RNA nucleotides in nucleus attach to DNA bases ON ONE SIDE of the DNA molecule  RNA uses “uracil” NOT “thymine" How do bases pair up? DNA base RNA base A U T A C G G C  Transcription (3) Covalent bonds form between sugars and phosphates on mRNA strand. (4) mRNA molecule is released and DNA “zips” back up. *RNA polymerases (enzymes) guide transcription by reading the DNA code Translation→ Using mRNA to make proteins Occurs at the ribosomes  Terms associated with Translation... Proteins are made up of many amino acids. The order of bases is what determines which a.a. get lined up & which proteins get made. 3 mRNA nucleotides (or bases) = CODON 3 tRNA nucleotides (or bases) = ANTICODON 3 bases code for 1 amino acid.  Anticodons are specific... tRNA will only bring a certain amino acid to ribosomes Ex. CCA = Glycine ONLY Start codon (AUG)—methionine—causes ribosomes to start translation Stop codons (UAA, UAG, UGA)—cause ribosomes to stop translation Translation Steps: (1) mRNA leaves nucleus and travels to ribosome (site of protein synthesis) (2) Amino acids are brought to the ribosome by tRNA. The tRNA bases (ANTICODONS) pair with the mRNA bases (CODONS). Base pairing: mRNA base tRNA base A U U A C G G C  tRNA molecule:  (3) Amino acids join together by a peptide bond to form a protein (polypeptide). Peptide bonds  Diagram of Protein Synthesis **Cut out and paste in your notes** Click image for 3 min video recapping P.S.  DNA vs. RNA DNA RNA Contains thymine Uracil replaces Thymine Double stranded Single stranded Deoxyribose sugar Ribose sugar Stays in nucleus Travels between nucleus and cytoplasm Only one type 3 types: mRNA , tRNA, rRNA  Importance of RNA: mRNA (messenger RNA) takes the code out to the ribosomes tRNA (transfer RNA) brings amino acids to the ribosomes to make proteins. Information is transferred from DNA to RNA to proteins. This is known as the central dogma of molecular biology.  Codon Wheel *Cut out and paste your codon wheel into your notebooks!*