Chapter 18 Flashcards
What are the three regulatory processes that appear in operons?
- Repressible operons
- Inducible operons
- Glucose repression
Why are repressible operons and inducible operons negative feedback?
Active forms turn operon off
Which type of operon is anabolic and which is catabolic? Why?
- Repressible = anabolic because endergonic (synthesis)
- Inducible = catabolic because exergonic (break down)
When does glucose repression occur and on which operon?
Lac operon when glucose level is high (meaning cAMP level is high) and lactose level is high; lactose is broken down into food
What are the 2 ways bacteria can regulate metabolism?
- Feedback inhibition
- Gene regulation
In bacteria, why are parts of gene condensed into operons?
To not waste parts and conserve energy
Differential gene expression
Expression of different genes by cells with same genome
What are the histone modification and which are the DNA modifications?
Histone: acetylation (loosens histone’s grip on DNA)
DNA: methylation (tightens structure), phosphorylation (loosens methylated structure)
Which chromatin remodeling function is best for long-term gene inactivation?
DNA methylation
What happens in histone actylation?
Acetyl is added to lysine on histone tails to loosen its grip on DNA
What is genomic printing and what helps it occur?
Picking of maternal/paternal allele; DNA methylation
What is epigenetic inheritance?
That things other than nucleotide sequence can be passed down as a trait
What are the 2 types of control elements?
Proxal and distal
What are the 2 specific transcription factors?
Activators and repressors
In post-translational modification, what processes help to activate polypeptide chain into protein?
- Cleavage
- Addition of chemical groups
