Term
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Definition
• Enzyme that helps complement DNA strands during replication
• Can only build 5’ to 3’ direction
• Checks for errors as it goes, other enzymes check/fix UV mutations also |
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Term
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Definition
• When DNA gets copied so that daughter cells can each have a copy
• Each single strand = template for complementary strand
• Separation, complement
• DNA Polymerase, DNA ligase |
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Term
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Definition
• Starts at replication origins
• Replication forks on either side separated and copied
• Eventually replication forks meet each other separation complete |
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Term
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Definition
• DNA polymerase complements, but can only go 5’ to 3’ direction
• On 3’ to 5’ strand, does it piecemeal and creates fragments: Okazaki fragments
• DNA ligase binds the fragments together |
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Term
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Definition
| • A part of a DNA strand that contains the instructions for a given protein |
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Term
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Definition
• Intermediate between DNA and proteins—has information to make a polypeptide
• Thought to be the orinal genetic material |
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Term
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Definition
• Process that makes DNA into mRNA
• Nucleoid for prokaryotic cells/nucleus for eukaryotic ones
• RNA polymerase does it
• Happens at the same time as translation in prokaryotes |
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Term
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Definition
• Enzyme that carries out transcription
• Attaches onto promoter region
• Temporarily separates DNA strands, puts complementary RNA nucleotides on one (using Uracil)
• Stops at termination point (stop codon) |
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Term
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Definition
• Place where RNA polymerase attaches onto DNA before transcription
• A few nucleotides before a gene |
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Term
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Definition
• Help control which genes are expressed, prevents transcription for a certain gene
• Proteins that bind to operator region of DNA—between promoter and gene
• Some always active and bind to DNA, others sometimes release |
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Term
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Definition
| • Temporarily inactivates permanent repressors, used for genes that a cell needs only sometimes |
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Term
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Definition
• Molecules that activate some repressors
• e.g. tryptophan in E. coli (page 100) |
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Term
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Definition
• Proteins required for transcription in eukaryotic cells
• Activate RNA polymerase |
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Term
| Post-Transcription Processing |
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Definition
• Happen in eukaryotes
• Add guanosine triphosphate at 5’ end, add poly(A) tail at 3’ end
• Get rid of introns and splice exons |
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Term
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Definition
• Parts of mRNA that aren’t necessary to make the protein
• Get excised during post-transcription processing |
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Term
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Definition
• The coding regions of mRNA
• Get spliced together at a spliceosome—large complex of proteins
• Genes can code for more than one protein depending on how it’s spliced |
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Term
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Definition
• mRNA read/converted polypeptide chain
• Happens inside ribosomes—two halves of ribosome attach on opposite sides of mRNA
• Carried out by tRNA
• mRNA is read three nucleotides at a time, always starting with AUG
• Once the right tRNA matches up, its amino acid is bonded to the existing polypeptide
• Happens at the same time as transcription in prokaryotes |
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Term
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Definition
• Three-nucleotide sequences of mRNA—64 different ones are possible
• Some codons code for the same amino acid
• Start codon: AUG. Stop codons: UAA, UAG, UGA |
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Term
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Definition
• Carries out translation
• Attached to one of 20 amino acids on one side, attaches to mRNA on other side
• 20 different ones, one per amino acid, have an anticodon on them |
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Term
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Definition
• Changes in the nucleotide sequence of DNA from environmental factors or mistakes
• Can have a huge effect, little effect, or no effect
• Substitution/point mutation: one base-pair replaces another one
• Insertions or deletions are usually more harmful because of a potential frame-shift |
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