Week 6 Flashcards
What is one technique used to study cell biology?
• Biochemistry
- Whole cell extracts
- ‘Destroyed’ the cell
- Fractionation
- In vitro assays (cell free)
What are forward genetics?
phenotype is known,
gene (genotype) is unknown
What is reverse genetics?
Gene is known, determine
role of the gene and the phenotype of mutations.
What is cell biology?
study of processes e.g. cll growth, division and maintenance. By maintenance we mean a cell us able to maintain itself shape and function.
Processes are controlled by mechanisms . Regulated system which can respond to intracellular and extracellular signals (other cells or surrounding environment).
What do the signals enable the cell to do?
signals enable the cell to maintain itself in its environment.
- where this is a unicellular organism or wthether you are looking at a cell within a multicellular organism.
- How those cells respond within the context of the organ to enable the shapeof the organ and the shape of the organism itself to function and form correctly.
Why are cells complex and dynamic?
Whole cell level.
- -Changes in morphology.
- -Complex at intracellular levels.
Explain biochemistry in more detail.
Cells are lysed and destroyed and they are open.
- –contents are then extracted and are separated out into fractions. so this is usually the process. Whereby the contents of the cell are loaded onto a gradient.
- –This is then spun and the samples then separate out into different fractions according to their density within the gradient.
What is another technique is used to study cell biology?
• Genetics
- Mutants versus control wild type- changes in proteins.
- Looking at mutants helps us to understand how mutants can change the function of a particular protein.
- Relationship between genotype and phenotype
What is the context of imaging cells through microscopy?
To understand a particular process in a cell.
• The naked eye can only directly perceive the first two panels
• The resolution of the light microscope takes you to the 4th panel
• The electron microscope takes you to the 7th/8th panel
• X-ray crystallography allows you to go to the 9th
Anything under ____ distance then you need to use a microscope.
2mm
Why are microscopes important?
They magnify detail within a sample, and so light microscopes enable you to look at detail within a sample down around to the 200/250micrometer size.
What would you use when looking at things closer than 200/250μm apart?
Electron microscope
What would you use to look at how a protein folds/interacts with another?
Use an x-ray or crystallography.
What is something you cant see under a light microscope?
Thylakoids
What are the properties of microscopy?
- Observe ultrastructural detail
- Electron microscopy (resolution < 250nm)
- Transmission electron microscopy (TEM):
electrons pass through the sample. - Scanning electron microscopy (SEM):
electrons emitted from the surface of an
object shows topography
Cell biology studies the
processes and mechanisms of cells
Why is the cytoskeleton important?
dynamic structures, provide mechanical strength
How do proteins reach there final destinations?
Proteins reach their final destination due to signal sequences (amino acid
‘postcodes’)
What aids the transport to final destinations?
• Interaction with receptors aids transport to final destination
How do proteins move?
• Proteins can move via sorting or in vesicles
How is vesicle formation ordered and controlled?
Vesicle formation is ordered and controlled by a set of proteins which bend
the membrane, pinch off the vesicle and coordinate delivery