What is gene expression?
The ‘turning on’ of a gene to produce RNA and proteins (if the gene is coding)
What is protein expression?
The type and abundance of proteins in the cell
What are the two main components of phenotypic variation?
- Differing alleles
Differing regulation of gene and protein expression
What are the five levels of eukaryotic gene regulation?
- Transcriptional
- Post-transcriptional
- Translational
- Post-translational
- Epigenetics
What three things does an organisms phenotype depend on?
- Cell number
- Cell type
- Cell function
What is possible if we are able to control tissue-specific transcription?
Transdifferentiation - changing one tissue type into another
What do complexes of proteins, nucleic acids, and lipids form?
Molecular machinery to carry out cellular processes
What are three examples of molecular machinery complexes?
- Kinetochores (DNA-protein)
- Ribosomes (RNA-protein)
- Vacuolar-type H+ ATPase (lipid-protein)
Besides molecular machinery, how else are cellular processes regulated?
Signal-transduction pathways - ordered associations of multiple proteins
What is required to start a signal-transduction pathway?
Extracellular stimulus (eg. nutrient conditions in bacteria), hormones (such as cholesterol)
What is included in the signal-transduction pathway components?
- Ligand
- Cell surface receptor
- Kinase cascade
- Transcriptional regulator
What do signal transduction pathways ensure?
Proper gene expression or physiological response from stimulus
What is needed to fully decipher and understand how life works?
- Identity of all parts/macromolecules in the cell/organism (nucleic acids, proteins, lipids, metabolites)
- Abundance and dynamics of each macromolecule
- Regulation (multiple levels) and functions of each macromolecule
- Interactions between macromolecules and their biological significance
What can abnormalities in regulation lead to?
Alternate phenotypes - some of which may be disease causing
What is the approach to systems biology?
Analyzing all components and their interactions at once to obtain a systems view of a cell/organism
What is systems biology the opposite of?
Reductionism
What four things are important to achieve a system level understanding?
- Structures
- Dynamics
- Control
- Design
