Flashcards
F215 Genetic Control
Cards in this deck (25)
- 1Genetic TerminologyGenetic Terminology
- 2Co-dominanceAlleles which both contribute to the phenotype
They are both expressed in the phenotype - 3Dominant allelean allele which is always expressed in the phenotype, even if a different allele for the same gene on the other chromosome is present
- 4Recessive allelean allele which is only expressed if both alleles are identical and there are no dominant alleles
- 5Genelength of DNA, sequence of nucleotide bases which codes for one or more polypeptide
occupies a specific locus on the DNA - 6Genomeall of the DNA an organism has
- 7Polypeptidechain of amino acids joined by peptide bonds forming a polymer
- 8ChromosomeOne molecule of DNA which contains many genes
they come in homologous pairs, one from the mother and one from the father - 9Histone ProteinDNA double helix associates with histone protein to produce chromosome
- 10Transcriptionthe production of a single stranded mRNA copy of a gene
- 11Translationthe assembly of polypeptides using mRNA and ribosomes
- 12Codonstriplets of nucleotide bases
- 13control of protein synthesis and protein activationcontrol of protein synthesis and protein activation
- 14Switched offGenes which aren't being transcribed. The proteins they code for aren't being produced.
- 15InterphaseBefore mitosis and meiosis, the cells DNA unravels and replicates = 2 copies of each chromosome in each cell
- 16Switched onGenes which are being transcribed are described as being switched on. These genes are being used to produce polypeptides
- 17Operonsprotein production in prokaryotes and eukaryotes
involves:
- structural genes
- control elements
- often regulatory genes - 18Structural Genesgenes which codes for useful enzymes
- 19control elementmade up of:
- promotor = RNA polymerase binds to
- operator = transcription factor binds to - 20regulatory genecodes for transcription factor
- 21transcription factorprotein that binds to the operator part before the gene, that switches the gene on or off
there are two types:
- activator
- repressor - 22activator factorin the presence of the activator factor, the gene will be transcribed and the proteins will be synthesised
- 23repressor factorin the present of the repressor factor, the gene will not be transcribed and the proteins will not be synthesised
- 24environmental changeschanges in the environment can cause the binds or structural change to the protein of the transcription factor on the gene
this will mean that the transcription factor will not longer be able to bind to the operator part, and the opposite will take place
- genes which were switched off, will be transcribed
- genes which were switched on, will stop being transcribed - 25Lac operonE.coli normally respires glucose, but when glucose levels are low, lactose can be used
the gene Lacl codes for enzymes which breakdown lactose e.g. beta-galactosidase and lactose permease
normally (in conditions where there high concentration of glucose) a repressor factor is produced by the regulatory gene which binds to the operator part on the gene to stop the synthesis of these enzymes
when there is a higher concentration of lactose than glucose, the lactose molecules bind to the transcription factor, changing the shape of the repressor factor so it can no longer bind to the operator site and therefore the transcription of the end
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- A Levels Biology (F215 - ) Flashcards on F215 Genetic Control, created by Gurdev Manchanda on 02/02/2016.
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- Gurdev Manchanda
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