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Published byMorgan Fox Modified over 8 years ago
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DNA replication DNA makes a copy of itself BEFORE the cell divides Transcription RNA is made by base pairing with a DNA template Translation mRNA templates are decoded into proteins
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Process › DNA Helicase unwinds and unzips the double helix › DNA polymerase brings in free DNA nucleotides to the two sides of the DNA molecule DNA can only replicate in the 3’ to 5’ direction so small replication bubbles form instead of one long continuous process › DNA Ligase proofreads and bonds the new strands › Hydrogen bonds form › Process is semiconservative – each DNA molecule has an old and a new side
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Occurs in the NUCLEUS › DNA can’t leave the nucleus because there is a risk of damage or lost sections Decodes 1 gene Process › RNA polymerase brings in free RNA nucleotides to the DNA template (1side of DNA) › DNA base pairs match with RNA base pairs › RNA nucleotides bond together and leave the nucleus through a nuclear membrane pore
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DNA Side 1 = ___ ___ ___ ___ ___ ___ DNA Side 2 = ___ ___ ___ ___ ___ ___ (template) RNA = ___ ___ ___ ___ ___ ___ Three types of RNA can be made › Messenger (mRNA) = the code of DNA; the type we will focus on for protein synthesis › Ribosomal (rRNA) = RNA used to make a ribosome › Transfer (tRNA) = moves amino acids around in the 2 nd part of protein synthesis
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Three nitrogen bases make up a codon which makes a protein oh yes it does. When mRNA lands on a ribosome the process has begun. Each codon pairs up with an anticodon found on the transfer RNA Each tRNA brings an amino acid to ribosome to stay When two of them are side by side a peptide bond forms right away This keeps on going until a stop code is read and a polypeptide has been made. This is the process of translation. There is not much more to say. But proteins are made all the time every second of the day.
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The process of converting an mRNA codon into a polypeptide (protein) chain Occurs in the cytoplasm or rough ER Important Terms › mRNA Codon – 3 nitrogen bases that code for an amino acid; 64 possible combinations › tRNA Anticodon – 3 nitrogen bases that complimentary base pair with a mRNA codon › Peptide bond – bond formed between two amino acids
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Process › mRNA lands on a ribosome (space for 2 mRNA codons at a time) › Start codon of a gene AUG attracts a tRNA anticodon › tRNA codon bring in an amino acid (met) › The next mRNA codon attracts another tRNA anticodon which brings in another amino acid › A peptide bond forms when two amino acids are side by side › Ribosome moves down and another mRNA codon is read followed by another amino acid coming in; 1 st tRNA moves out › New amino acid bonds to the existing bonded amino acids › Process continues until a STOP codon (UAA, UAG, UGA) is read › Polypeptide is molded into it’s shape to make a protein
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DNA Side 1___ ___ ___ ___ ___ ___ DNA Template___ ___ ___ ___ ___ ___ mRNA codon___ ___ ___ ___ ___ ___ rRNA anticodon___ ___ ___ ___ ___ ___ Amino Acid ___________ ____________
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