Quiz 1 Flashcards
What is the difference between prokaryotic and eukaryotic gene expression?
Prokaryotic is in the cytoplasm and eukaryotic is in the nucleus and goes to ribosomes in the cytoplasm which takes longer.
What is the key to the transcription process?
Enzymes
What controls the RNA polymerase during the transcription process?
Regulatory proteins
Regarding prokaryotic and eukaryotic organisms, which gene expression process is faster? (and know why)
Prokaryotic expression, because it everything happens in the cytoplasm
What is a difference between a prokaryotes and eukaryotes method of gene control?
Prokaryotic cells respond independently to their immediate environment. Eukaryotic cells need the whole organism to respond to the change needing the signal to travel far.
Negative control is mediated by proteins called ______________ (which are proteins that bind to the regulatory site on DNA called operators to prevent or decrease the initiation of transcription).
regulatory proteins - repressors
The repressors do not work alone. Each responds to specific _____________ molecules which can alter the conformation of the repressor to either enhance or abolish its binding to DNA (just like an allosteric protein and cofactor).
effector molecules
Positive control is mediated by ______________, which is another class of regulatory proteins. They can bind to DNA and stimulate the initiation of transcription
activators
Prokaryotic gene are often organized into ________________ (multiple genes that are part of a single transcription unit having a single promoter).
operons
_____________ occurs when enzymes for a certain pathway are produced in response to a substrate. For example, if bacteria encounters lactose, it beings to make the enzyme necessary to utilize lactose (i.e. lactase).
Induction
_____________ occurs when bacteria are capable of making biosynthetic enzymes and they are not actively producing them (i.e. do not make it if you do not need it).
Repression
The presence and absence of lactose is not the only factor which can affect gene expression of lactase. What else discussed in class can affect the gene expression of lactase?
Multiple environmental factors (glucose)
Some small RNAs were discovered within eukaryotic cells (which are not located within prokaryotic organisms). One type of regulatory RNA is now called a micro-RNA or mi-RNA. Which statement describes any information discussed in class regarding mi-RNA?
Discovered in a nematode, help intron Extron deletion, 1,917 different types, controls over 1/3 of human DNA
Some small RNAs were discovered within eukaryotic cells (which are not located within prokaryotic organisms). One type of regulatory RNA is now called small interfering RNAs or siRNAs. Which statement describes any information discussed in class regarding si-RNA?
Found in plants, interfere with the process of gene expression
could potentially help turn enzymes on and off, allowing things even like viruses to turn off
The translation of processed mRNA transcript by ribosomes in the cytoplasm involves a complex of proteins called _______________ (gene expression is regulated by the modification of one or more of these factors).
Translation Factors
