Lecture 1 Flashcards
What is the difference between prokaryotic and eukaryotic gene expression?
Eukaryotic - more complex
Prokaryotic - less complex
What is the key to the transcription process?
- RNA polymerase
- Without RNA polymerase - you can’t make mRNA
What controls the RNA polymerase during the transcription process?
Regulatory Proteins
- Different types of proteins/enzymes that control the ability of RNA polymerase to bind to the promoter
Utilized = can inhibit or stop the attachment of RNA polymerase to promoter
- Negative control = stop transcription
- Positive control = initiate transcription
Regarding prokaryotic and eukaryotic organisms, which gene expression process is faster? (and know why)
Don’t have as many obstacles as Eukaryotic
can do transcription and translation at the same time
What is the difference between prokaryotes’ and eukaryotes’ methods of gene control?
Prokaryote primary function of gene control =
Prokaryote primary function of gene control =
One cell -
* Everything surrounding the cell is an external environment
- ex. acid attack - will send signal inside the cell - expect a response - genetic expression will be created to resist/ provide a necessary response to the specific problem
* Control things by looking at an immediate environment
KEYWORD = IMMEDIATE ENVIRONMENT
The eukaryotic primary function of gene control =
- takes longer - is based on different stimuli
- The external environment has to go through multiple different cells just to send a signal to a specific cell
* ex. Something is wrong within a bone cell - the external environment signal has to go through skin cells, vessel cells, muscle/tissue cells just to reach the bone - the external factor would have to go through the whole organism for a specific function - therefor “whole organism”
* Multicellular organisms can not respond to the immediate environment
**the whole organism** is what matters rather than 1 cell
KEYWORD = WHOLE ORGANISM
A 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). Fill in the blank.
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). Fill in the blank.
effector
Positive control is mediated by ______, which is another class of regulatory proteins. They can bind to DNA and stimulate the initiation of transcription. Fill in the blank.
activators
Know this diagram (i.e. the basic parts and what process it is representing).
Question 9 in lecture 1 study guide
Know this diagram (i.e. the basic parts and what process it is representing).
Question 10 in lecture 1 study guide
Prokaryotic gene are often organized into _____ (multiple genes that are part of a single transcription unit having a single promoter). Fill in the blank.
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). Fill in the blank .
gene regulation / lac operon
________ 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). Fill in the blank.
Repressors
Know what the difference between these two diagrams is (i.e. know which one is activated and which one is not activated).
Question 14 in lecture 1 study guide
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?
Glucose presence
Glucose repression - glucose level is very high,
inducer absent, promoter not activated because
glucose is present you don’t need to create the
glucose presence
