Proteins Flashcards
What is the proteome?
The entire set of proteins expressed by a genome
Why is the proteome smaller/larger than the number of genes, particularly in eukaryotes?
It is larger because more than one protein can be produced from a single gene as a result of alternative RNA splicing
What do non-coding RNA genes, code for?
tRNA, rRNA and RNA molecules that control the expression of other genes
Name some factors affecting the set of proteins expressed by a given cell type
Metabolic activity of the cell, cellular stress, response to signalling molecules and diseased vs healthy cells
What is unique about eukaryotic cells?
They have a system of internal membranes, which increases the total area of the membrane
Why is it eukaryotic cells have their unique feature?
Eukaryotes have a relatively small surface area to volume ratio (because of their size) and therefore the plasma membrane is too small an area to carry out all the vital functions carried out by membranes
Describe the structure of the endoplasmic reticulum
It forms a network of membrane tubules continuous with the nuclear membrane
What is the job of the endoplasmic reticulum?
To fold proteins and transport translated proteins to the Golgi apparatus
What is different between the RER and the SER
RER has ribosomes on its cytosolic face and SER lacks ribosomes
Describe the structure of the Golgi apparatus
A series of flattened membrane discs
What is the job of the Golgi apparatus?
To process and package the proteins to be used inside/outside the cell
What are lysosomes?
Membrane-bound protein bound organelles containing a variety of hydrolases that digest proteins, lipids, nucleic acids and carbohydrates
What are vesicles and what do they do?
They are fluid filled sacs which transport materials between different membrane compartments
Where does the synthesis of all proteins begin?
In the cytosolic ribosomes
Where does the synthesis of cytosolic proteins occur?
In the cytosolic ribosomes
