Full Length Exam Weaknesses (BIO) Flashcards
If DNA is methylated the genes are turned (on/off) because…
off, the methyl groups encompass their tails around the DNA, which then restricts access
If DNA is de-methylated, the genes are turned (off/on) because..
tails are loosened, allowing transcription factors access to the DNA
This process is a post-translational modification that attaches a negative charge to a serine, threonine, or tyrosine via a ____ group
phosphorylation, phosphate group
Phosphate groups are attached by a (type of enzyme)
kinase
This process __________, is a post-translational modification where the addition of a ____ group reduces the (+) charge on a histone, which then reduces its interaction with a (-) charged phosphate group, making the DNA less tightly wound and more accessible to gene transcription
acetylation, acetyl group
If the DAM methylation sequence is blocked, what will NOT occur?
methylation, meaning transposition is more likely to occur (jumping genes)
Hemi-Methylated DNA
This allows the cell to distinguish between the old strand (methylated) and the new strand (unmethylated)
A - T base pairs have ____ hydrogen bonds between them, which means (MORE/LESS) energy is required to separate these bonds than C-G base pairs
2, less energy (C-G bonds have 3 Hydrogen bonds)
During PCR, denaturing (1st step) occurs at what temperature?
approx 95 celcius
During PCR, annealing (2nd step) occurs at what temperature?
approx 50-55 celcius
During PCR, extending (last step) occurs at what temperature?
approx 72 celcius
The signals from healthy neurons dissipate (slower/faster) than signals from neurons affected with multiple sclerosis
healthy neuron signals dissipate more SLOWLY
This enzyme removes a phosphate group from a substrate, and uses what molecule to do so?
Phosphatase, a water molecule
A POSITIVE, INDUCIBLE system, is one in which
the system is ALWAYS off until turned on- and since it is positive, the regulatory protein binds the activator (ex: lac operon)
A NEGATIVE, INDUCIBLE system, is one in which
the system is ALWAYS off until turned on- and since it is negative, the regulatory protein binds a repressor, until the inducer inactivates this repressor (ex: trp operon)
A Repressible system is always (ON/OFF) until turned ___
always ON, until turned off
How do proteases break peptide bonds?
By hydrolysis