BIOL 3110 Lecture Notes - Cytosine, Covalent Bond, Purine
Document Summary
All genes have a control site followed by a coding region. The gene needs to be activated by the control region before proteins can be made (refer also to fig. There are 2 copies of each gene (alleles) in the cell and each one has a minute nucleotide difference in order to differentiate the two. If a mutation occurs at one of the control site that causes the control region to be blocked from the regulatory protein then that allele becomes unviable. Cis-acting element mutations affect only the dna molecule to which it is attached. In trans-acting mutations prevents the expression of both alleles; therefore it is said to be diffusible. Cis-acting molecules are within the dna itself whereas trans-acting molecules are from the regulatory proteins that govern gene activity. The origin of replication would be the cis elements whereas the elements needed for replication would be the trans factors.
