Lecture 26. Gene Expression in Prokaryotes and Eukaryotes Flashcards
What produces distinct cell types ?
Differential gene expression patterns
Why in eukaryotes is the cell under complex control ?
They contain many different cell types and what makes one cell type different from another is the specific cohort of genes that each cell expresses
What are some cellular activities ?
- During cell division
- In response to stimulation with glucose
- In response to stress or starvation
What is gene expression fundamental to ?
What an organism can do and whether it can adapt to changing circumstances
Where do different cell types arrive ?
Embryonic development
What initiates different patterns of gene expression ?
Developmental signals
When can cell differentiation occur ?
Occurs during multiple stages of development including in the adult
What are the cells in the early embryo called ?
Blastomere
What types of cells do cells in the early embryo begin as ?
Totipotent
What are totipotent cells ?
Can differentiate into any cell type
In response to signals, what do cells that are totipotent differentiate into ?
Pluripotent, multipotent and finally fully differentiated cells
What are housekeeping genes ?
Genes that are expressed in practically all cells within a given organism
What do housekeeping genes include ?
RNA and proteins that are required to build common cellular structures, organelles and carry out basic functions of the cell
What are some types of housekeeping genes ?
- Structural proteins
- Enzymes for cellular metabolism
- Proteins and other enzymes for organelle synthesis and maintenance
What are tissue-specific genes ?
Genes which are relatively unique to each cell type
Where are tissue specific genes expressed ?
Specific cell types
What are the four mechanisms of different patterns of gene expression ?
- Transcriptional
- Post-transcriptional
- Translational
- Post translational
What does the transcriptional mechanism involve ?
Factors that affect RNA transcription
What does the post-transcriptional mechanism involve ?
Factors that affect stability or composition of RNAs
What does the translational mechanism involve ?
Factors that affect translation of mRNAs into protein
What does the post-transcriptional mechanism involve ?
Factors that affect protein function of activity state
What does RNA polymerase regulate RNA synthesis in tandem with ?
Transcription activators and repressors