| Term | Definition |
|---|
| what is a protein? | made up of a chain of amino acids (polypeptide) involved in all aspects of life EXCEPT energy source, each has a specific function, made by ribosomes |
| DNA | directs making of protein, recipe book for every protein in the body, stays in the nucleus, master copy of ALL genes, double stranded, contains T, deoxyribose nucleic acid |
| RNA | temporary copy of ONE gene, leaves the nucleus, single stranded, contains U, ribose nucleic acid; function is determined by the shape |
| mRNA | messenger rna carries a message for how to make a polypeptide from dna to the ribosome |
| tRNA | transfer rna brings amino acid from all over the cytoplasm to the ribosome |
| rRNA | ribosomal RNA makes up the ribosome |
| how did non-coding sequences get there? | debatable - here are 2 theories 1) viruses put their DNA inside ours or 2) it used to be relevant |
| why are majority of DNA non-coding? | so mutations that occur won't affect the organism |
| How many base pairs can be in every gene? | there can be thousands |
| what are the 3 steps of RNA processing (editing)? | 1) splicing 2) adding mG cap 3) adding a poly-A tail |
| mG cap | methylated guanine provides protection (indestructable) |
| poly-A tail | provides protection (a's will be eaten before the important stuff) |
| 3 steps of transcription | 1) initiation - the start marked by a promoter sequence 2) elongaion - building of the RNA strand by RNA polymerase 3) termination - RNA polymerase stops at the terminator sequence |
| splicing | the removal of introns and putting together of exons done by the spliceosum |
| transcription | RNA polymerase binds to DNA and uses one strand as a template to assemble a strand of RNA |
| promoter | the place on DNA where transcription begins |
| intron | a sequence of nucleotides in RNA that does not code for a protein |
| exons | a sequence of nucleotides in RNA that does code for a protein |
| a-site | contains incoming amino acid |
| P-site | contains growing polypeptide |
| E-site | where tRNA exits |
| codon | the sequence of 3 nitrogenous bases on mRNA that codes for 1 amino acid |
| anti-codon | sequence of 3 nitrogenous bases on tRNA that complements the codon |
| start-codon | aug where translation starts |
| stop-codon | a codon that doesn't code for tRNA |
| point mutation | a mutation that occurs at a single point in a DNA sequence |
| substitution | a point mutation where one base pair is replaced with a different one |
| possible repercussions of substitutions | 1) missense ( one amino acid changes to a different one) 2) silent (no change) 3) nonsense (premature stop) |
| insertion | frame shift mutation where one base pair is added |
| deletion | frame shift mutation where one base pair is deleted |
| possible repercussions of insertion/deletion | 1) frame shift (every amino acid changes after the point of mutation) 2) nonsense premature stop |
| expressed gene | gene that is "turned on" or turned into protein |
| gene regulation | expressing or not expressing certain genes |
| operator | region of the chromosome in an operon to which the repressor binds when the operon is "turned off" |
| operon | group of genes operating together |
| enhancer | enhances expression by allowing transcription to happen by binding to and removing the repressor |
| repressor | binds to the operator to act as a road block for RNA polymerase |
| hox genes | master control genes for the expression of other genes; they direct differentiation |
| why is gene regulation more complicated in multi-cellular organisms | cells differentiate to do different jobs and become specialized |
| differentiation | when cells become specialized in structure and function |
| process of protein synthesis | 1) DNA unwinds in the nucleus 2) DNA "unzips" exposing base nucleotides 3) RNA nucleotides attach themselves to exposed DNA bases i.e. G's go with C's etc. 4) when RNA molecule is complete it breaks away from DNA strand 5) DNA rejoins and coils 6) RNA processing occurs 9) mRNA leaves the nucleus and travels to the ribosome 8) specific amino acids combine with tRNA and are taken to the ribosome 9) ribosome moves along the mRNA attaching a proper tRNA anti-codon to the mRNA codon 10) amino acids of the tRNA molecules are joined 11) at the end of the mRNA strand is a codon that does not code for any amino acid (stop codon) 12) the message is stopped and the polypeptide chain breaks away from the ribosome 13) one mRNA molecule is used to make several protein copies and then breaks down |
Combine with other sets
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