unit 1 biology cover Flashcards
In affinity chromatography, what is created?
A solid matrix or gel column is created with specific molecules bound to the matrix or gel.
What does gel electrophoresis do?
It separates proteins and nucleic acids. Charged macromolecules move through an electric field applied to a gel matrix.
What are immunoassay techniques used for?
To detect and identify specific proteins.
What is bright-field microscopy commonly used for?
To observe whole organisms, parts of organisms, thin sections of dissected tissue or individual cells.
What does fluorescence microscopy use?
Specific fluorescent labels to bind to and visualise certain molecules or structures within cells or tissues.
What does aseptic technique do?
It eliminates unwanted microbial contaminants when culturing micro- organisms or cells.
How can a microbial culture be started?
Using an inoculum of microbial cells on an agar medium, or in a broth with suitable nutrients.
What are examples of secreted proteins?
Peptide hormones and digestive enzymes.
What happens to the terminal phosphate of ATP?
It is transferred to specific R groups.
What are the receptors for hydrophobic signalling molecules?
Transcription factors.
What do hydrophilic signalling molecules bind to?
Transmembrane receptors.
What can phosphorylation cascades result in?
The phosphorylation of many proteins as a result of the original signalling event.
What does exercise do?
It triggers recruitment of GLUT4, so can improve uptake of glucose to fat and muscle cells in subjects with type 2.
What happens when the action potential reaches the end of a neuron?
It causes vesicles containing neurotransmitters to fuse with the membrane — this releases neurotransmitter, which stimulates a response in a connecting cell.
What happens following repolarisation?
The sodium and potassium ion concentration gradients are reduced. The sodium-potassium pump restores the sodium and potassium ions back to resting potential levels.
What amplifies the signals in rod cells?
A cascade of proteins.
What does increase in cGMP result in?
The closure of ion channels in the membrane of the rod cells, which triggers nerve impulses in neurons in the retina.
What does a very high degree of amplification result in?
Rod cells being able to respond to low intensities of light.
What does cell division require?
Remodelling of the cytoskeleton.
When does progression occur in cell division?
If sufficient phosphorylation is reached.
What is an example of an external death signal?
The production of death signal molecules from lymphocytes.
What is an example of an internal death signal?
DNA damage.
What does an internal death signal resulting from DNA damage cause?
Activation of p53 tumour- suppressor protein.
What do both types of death signal result in?
The activation of caspases (types of protease enzyme) that cause the destruction of the cell.
What is apoptosis essential during?
Development of an organism to remove cells no longer required as development progresses or during metamorphosis.
When may cells initiate apoptosis?
In the absence of growth factors.
