Transcript LN #22
LN #22 DNA to Protein California Content Standards Genetics 4a. Students know the general pathway by which ribosomes synthesize proteins, using tRNAs to translate genetic information in mRNA. 4b. Students know how to apply the genetic coding rules to predict the sequence of amino acids from a sequence of codons in RNA. DNA Full Name Sugar # of strands Nitrogen bases Types Location RNA Full Name Sugar # of strands Nitrogen bases Types Location DNA Deoxyribonucleic acid RNA Ribonucleic acid Full Name DNA Deoxyribonucleic acid Sugar Deoxyribose # of strands Nitrogen bases Types Location RNA Ribonucleic acid Ribose Full Name DNA Deoxyribonucleic acid Sugar Deoxyribose # of strands 2 Nitrogen bases Types Location RNA Ribonucleic acid Ribose 1 Full Name DNA Deoxyribonucleic acid Sugar Deoxyribose # of strands 2 Nitrogen bases Adenine (A) Types Location RNA Ribonucleic acid Ribose 1 Guanine (G) Cytosine (C) Adenine (A) Guanine (G) Cytosine (C) Thymine (T) Uracil (U) Full Name DNA Deoxyribonucleic acid Sugar Deoxyribose # of strands 2 Nitrogen bases Adenine (A) Types Location RNA Ribonucleic acid Ribose 1 Guanine (G) Cytosine (C) Adenine (A) Guanine (G) Cytosine (C) Thymine (T) Uracil (U) One type DNA Three types mRNA, tRNA, rRNA Full Name DNA Deoxyribonucleic acid Sugar Deoxyribose # of strands 2 Nitrogen bases Adenine (A) RNA Ribonucleic acid Ribose 1 Guanine (G) Cytosine (C) Adenine (A) Guanine (G) Cytosine (C) Thymine (T) Uracil (U) Types One type DNA Three types mRNA, tRNA, rRNA Location Nucleus Nucleus & cytoplasm In the Nucleus • Transcription – occurs in the nucleus – a portion of DNA is transcribed (copied) into mRNA. – mRNA is made by applying base pairing rules. • messenger RNA (mRNA) – carries the instructions for making proteins to the cytoplasm. – mRNA has codons. – a codon is a set of 3 bases that codes for an amino acid. there are a total of 20 amino acids that make up proteins. In the Cytoplasm • Ribosome – made of protein and ribosomal RNA (rRNA) – site where proteins are made. – mRNA attaches to the ribosome in order for protein synthesis to occur. Also found in the Cytoplasm • Transfer RNA (tRNA) – vehicle that brings the correct amino acid according to the directions on mRNA. – tRNA has a site that holds an amino acid and a site that bonds with mRNA. – the anticodon on tRNA bonds with the codon on mRNA. Translation 1. tRNA carrying an amino acid bonds to the mRNA. 2. a bond is formed between the amino acids. 3. the mRNA slides across the ribosome. the tRNA without an amino acids leaves the ribosome 4. tRNA carrying an amino acid bonds to the mRNA. End of Translation • Translation continues until a stop codon is reached. • When the stop codon is reached a releasing factor bond to the mRNA and the protein is released. Steps for making proteins DNA strand transcription mRNA translation Phe Gly Arg Phe Protein (amino acid chain) Summary • What are the differences between DNA and RNA? • What are the steps for making proteins? • Where in the cell do transcription and translation occur? • What is made during transcription? • What happens during translation?