test 8 Flashcards
- What is the difference between prokaryotic and eukaryotic gene expression?
-Prokaryotic: Travel farther because you are doing everything in the nucleus. Using 3 types of enzymes.
-Eukaryotic: You have to travel from the nucleus all the way out and do everything in the ribosome. Using 1 type of enzyme.
- What is the key to the transcription process?
RNA polymerase
- What controls the RNA polymerase during the transcription process?
All different types of regulatory proteins (different types of enzymes and proteins created that modulate the ability that RNA polymerase is going to work) Can have positive or negative controls and control ability of RNA polymerase to bind or stop (regulatory proteins)
- Regarding prokaryotic and eukaryotic organisms, which gene expression process is faster? (and know why)
Prokaryotes; can do it faster than eukaryotes, don’t have as many polymerases, can do translation and transcription at the same time
- What is a difference between a prokaryotes and eukaryotes method of gene control?
If you are a bacterial cell, you can’t be multicellular. Control things by looking at immediate environment.
- 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).
- Know this diagram (i.e. the basic parts and what process it is representing).
- 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.
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). Fill in the blank.
repression
- Know what the difference between these two diagrams is (i.e. know which one is activated and which one is not activated).
- 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?
There are so many substances and don’t know which one can take priority; glucose breaks down in aerobic respiration and its easy and gives us ATP molecules, much more than lactase. If glucose is present, lactase enzymes are usually not created.
- 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 an animal called nematode, discovered a new RNA (mi-RNA), some polymerases can make these micro RNAs, affect how introns and exons are recognized and removed, ⅓ of human genome is decided by mi-RNA
- 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?
small interfering; found in plants, doesn’t mean they can only be used in plants, if you put them in they can stop something from being encoded into the genome, have better control because they have control over what can be read, silence a certain part of your genome, don’t really know much about these yet, very specific
- 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). Fill in the blank.
translation factors
- _______________ shut down translation by binding to the beginning of the transcript so that it cannot attach to the ribosome. Fill in the blank.
Translation repressor proteins
- How can the initiation of translation be controlled? (know the information discussed on slide 9 Ch 16 PowerPoint)
factors let and help translation steps occur, repressors mean it stops translation from happening because the repressor will attach and shut down the steps. These two work together by working as an on and off switch.
- Know the different mechanisms for the control of gene expression. They are all located within this diagram.
- According to the video How Cells Become Specialized, what is special about stem cells inside a human blastocyst?
those cells will give rise to the placenta, they are like blank slates, they can become any type of body cell
- According to the video How Cells Become Specialized, how do transcription factors play a role in cell differentiation?
typically but not always- proteins and determine which areas of the DNA code will get transcribed into mRNA, then can make specific proteins that impact what a cell looks like and does
- According to the video How Cells Become Specialized, stem cells are not only found in embryos, which of these cells stated below can contain somatic stem cells as well?
muscle, skin, liver, or bone marrow