modification of genes and proteins
DESCRIPTION
Modification of Genes and Proteins. Brian Fitzgerald, Sam Kutana , and George Rakushkin. Summery of Transcription and Translation. mRNA is synthesized in the nucleus using unwound DNA, travels to tRNA in the cytoplasm, and is “decoded” to create a chain of amino acids. - PowerPoint PPT PresentationTRANSCRIPT
MODIFICATION OF GENES AND PROTEINS Brian Fitzgerald, Sam Kutana, and George Rakushkin
mRNA is synthesized in the nucleus using unwound DNA, travels to tRNA in the cytoplasm, and is “decoded” to create a chain of
amino acids.
Summery of Transcription and Translation
Transcription starts when RNA polymerase attaches itself to the promoter region of the DNA
Initiation of Transcription
After initiation, RNA polymerase unwinds the double helix of DNA. The unwound strand becomes a template on which a new RNA strand is synthesized
Elongation
After the pre-mRNA is created with transcription, it is processed by enzymes in the nucleus
Transcript Processing
After the mRNA is synthesized and released, it is fed through tRNA and creates a chain of amino acids based on codons in the
mRNA
Translation
An unfolded amino-acid chain folds itself as hydrophobic (black) peptides flee the watery cytoplasm.
Spontaneous Protein Folding
Because proteins are so complex, they must follow specific intermediate steps in order to achieve a complete folding
Intermediate Steps
Direct reversal is being used to repair damage done to a piece of DNA. Direct reversal is also used to reverse methylation
Direct Reversal
When nucleotides on only one side of a DNA strand are damaged, the cell can use the other side as a template for
replacement
Single- Strand Repair
Homologous recombination is being utilized to repair a double-strand break. Blue indicates broken DNA and red indicates that DNA’s sister chromatid
Double – Strand Break Repair
If “fishy” mRNA is discovered in a cell, all copies of the gene that would produce the mRNA are destroyed. This protects against viral duplication
RNA Interference
When a cell comes in contact with dsRNA, it is chopped up into smaller segments and then used to identify and destroy any RNA produced by the dsRNA
Cellular response to double stranded RNA (dsRNA)
Medical Applications of RNAi - Cancer - Lou Gehrig’s Disease - Huntington’s -Alzheimers
- Gene Identification