3.7/8 Cystic Fibrosis/Cell Structure Flashcards
Cystic fibrosis is a condition that…
Affects plasma membranes
Genetic disorder - caused by a faulty CFTR gene
CFTR (cystic fibrosis transmembrane conductance regulator) is made by the …
CFTR gene
CFTR transports chloride (Cl-) ions across…
The membrane
When chloride ions are actively transported out of the epithelium cells into the mucus it lowers the…
Water potential of the mucus
Water moves by osmosis out of the epithelium cells into the mucus
Meaning that the mucus is sticky enough to trap dirt and bacteria that enter the airways, but is also thin enough for the cilia to move the mucus upwards, preventing bacteria settling in the lungs
People with CF have a faulty version of the…
CFTR protein - has a different tertiary structure
Due to the different tertiary structure the protein cannot…
Transport chloride ions out of the cells. Instead the water potential of the much increases and leaves the mucus - the lack of water in the mucus means that it is very think and sticky
It is very difficult for the cilia to move the sticky mucus so it…
Builds up in the air passages
Build up of mucus in the air passages causes…
Persistent coughing and wheezing
Shortness of breath
Repeated lung infections
Repeated lung infections eventually lead to lung damage as bacteria grow in a layer in the lungs - biofilm when bacteria grow this way it is very difficult for…
Antibiotics and the immune system to destroy them
White blood cells, especially phagocytes, migrate to the lungs to destroy the bacteria - end up damaging the alveoli instead - reduces surface area for gas exchange
Other symptoms of CF are:
In the digestive system - thick mucus blocks the pancreatic duct. The enzymes that the pancreas produce cannot bet into the gut, so food is not digested properly - lead to pancreatitis developing. Also digested food is not developed properly
Reproductive tract - mucus blocks the ducts carrying the gametes - can lead to infertility
The CFTR protein is made in the…
Cytoplasm
The gene that codes for the CFTR protein is found in the…
Nucleus
A light microscope can be used to see the…
Overall structure of a cell
An electron microscope can see the…
Many smaller structures in a cell (ultrastructure)
An electron microscope uses a…
Beam of electrons - shorter wavelength than light so it gives a much better resolution
Resolution is the ability to see…
2 objects close together as separate objects
In a transmission electron microscope a beam of electrons is passed through a…
Very thin section of a specimen
Different parts of the specimen absorb more or less of the electrons producing a…
black and white image on a computer screen
The electron beam will only operate in a vacuum. This means that you cannot view living material in an…
Electron microscope
Light microscopes are useful because you can see the…
Specimen in colour and you can view living specimens
In the cell cytoplasm there is an extensive membrane system called the…
Rough endoplasmic reticulum (RER)
The RER links up with the…
Nuclear membrane
Inside the membranes are cavities called…
Cisternae
On the outside of the RER are darkly-staining structures called…
Ribosomes which synthesise proteins
