Molecular Biology Flashcards
Single-stranded RNA molecules that bind to mRNA in cytoplasm and prevent it from working by increasing its rate of degradation or promoting repression of translation. Does this before it can be translated by the ribosome. Will not make a protein.
*can regulate gene transcription and translation, formed in the cytoplasm
microRNA (miRNA)
21-23 nucleotides
These enzymes help to further process miRNA in the cytoplasm
(pre-miRNA to miRNA). When it comes out of nucleus still RNA.
dicer
Binds to RNA in the cytoplasm and prevents it from working. Can be used to turn off genes temporarily clinically. Used as an antiviral agent in plants typically.
Silencing RNA
Aides in the transcription in the nucleus to create RNA. Once the 2 nucleotide bases match up, this chops off the extra 2 phosphates.
RNA polymerase
UTP binds to A
GTP binds to C
in nucleus we have ATP, GTP, UTP, CTP
Stop codons (3) Start codon (1)
*Every 3 base pairs codes for one specific amino acid. Lots of redundancy! Redundancy occurs during translation.
UGA, UAA, UAG
AUG
Regulates gene expression and virus assembly. Fits into grooves of DNA. Activator will have this, looking for specific sequence of DNA.
Zinc finger
Zinc Finger:
This really wants to bind with an adenine - thymine?
This really wants to bind with a guanine - cytosine?
- Glutamine
- Arginine
Use when making copy of cell:
Enzyme that causes bonding of successive DNA nucleotides to one another, using high-energy phosphate bonds to energize these attachments
DNA ligase
What cells are permanently in the cell cycle?
Stem cells
Cell Cycle:
Have a bunch of gates here, gates determine if the cell can proceed or not (ex: protein not sufficient can not go on). Need to make all copies of proteins we will need for both cells from DNA here (will not be able to make in S phase).
*Most time spent in this phase
G1 phase
Cell Cycle:
Mutations can occur during this phase of cell cycle.
Therefore at the end of this phase a tough audit process occurs.
*if we can repair the cell we will, if not then it is eliminated (kill the cell)
S phase
This binds to the new polypeptide that is forming, tells it to stop until it gets to the rough ER and carries it to the rough ER. Once here translation can begin again and this leaves…
*Gene codes for this, tells ribosome to stop and wait until we get to the rough ER.
Signal Recognition Peptide (SRP)
Can have one gene code for more than one protein. This is known as?
-Same gene is coded for 2 different proteins in 2 different organs that have 2 different functions
Splice Variance
Don’t have nucleus. Once they start making RNA - ribosomes bind on immediately. What polymerase transcribes is exactly what the ribosomes translate.
With humans, ribosomes only see what comes out of nucleus (post processing).
Bacteria
These give bacteria power - such as antibiotic resistance.
Plasmids
