DNA Replication/Transcription/Regulation PT.2 Flashcards
Chapter 18 & 20
Chapter 18
What is the operon and what does it include?
- Operon: stretch of DNA that includes the operator, the promoter, and the genes they control
- Operator: on-off switch to control function of genes
Chapter 18
What are the types of regulators?
- Repressor: swiches operon off; prevents gene transcription
- Corepressor: helps repressor switch operon off
- Inducer: inactivates repressor so that operon is turned on
- Activator: tunrs on transcription of a gene that is normally off
Chapter 18
What is the difference between a repressible and inducible operon?
- Repressible operons: binding of repressor to operator shuts off transcription (enzymes are in catabolic functions)
- Inducible operons: inducer inactivates repressor and turns on transcription (enzymes are in anabolic pathways)
Chapter 18
What is Differential Gene Expression?
Expression of different genes by cells with the same genome
Chapter 18
What is histone acetylation?
- Acetyl groups are attatched to amino acid in a histone tail
- Opens us chromatin structure and promotes initiation of transcription
- Addition of methyl groups to make DNA usable
Chapter 18
What is DNA methylation?
- Addition of methyl groups to certain bases in DNA
- Associated with reduced transcription
- Causes long-term inactivation of genes in cellular differentiaion
Chapter 18
What is epigenetic inheritance?
Inheritance of traits transitted by mechanisms not directly involving the nucelotide sequence
* Epigenetics: how behaviors and environment can cause changes that affect the way genes work
* Changes the way body reads DNA
Chapter 18
What are control elements?
- Segments of noncoding DNA that serve as binding sites for transcription factors
- Help regulate percise transcription and gene expression
Chapter 18
What is alternative RNA splicing in RNA processing?
Different mRNA molecules from the same primary transcript
Chapter 18
What is cell differentiation?
- Def; Process by which cells become specialized in structure and function
- Morphogenesis: phycial process that gives organisms its shape
- Induction: signal molecules cause changes in nearby target cells
- Determination: make a cells become a particular type of cell
- percedes differentiation
Chapter 18
What are homeotic genes?
Regulates the development of anatomical structures in various organisms
Chapter 18
Important terms to knwo for Cancer
- Proto-oncogenes: cell divsion gene
- Oncogenes: mutates proto oncogenes; becomes dangerous
- Tumor Suppressor Genes (p53): stops replication
