Proteins Flashcards
What are proteins made up of?
A polymer of amino acids, that is one or more polypeptide chains
What is the rough E.R’s function in protein secretion?
It acts as a channel of safe passage for the newly synthesised proteins
What is the difference between transport and secretion vesicles?
Transport vesicles take proteins from the E.R to the Golgi body, whereas secretion vesicles take proteins from the Golgi body to the plasma membrane where they are then secreted
What is the Golgi bodies role in protein secretion?
It modifies and tags the proteins so they can then be sent to be secreted
What is an amino acid comprised of?
A carboxyl group, amine group and Varying R functional group
NH(2)-CHR-COOH
What do R groups do?
They distinguish one amino acid from another, and give it its chemical properties
What properties vary from one amino acid to the next?
Acidity, polarity and charge
How do amino acids join together?
A peptide bond forms between the carbon from one molecule and nitrogen from another, via condensation polymerisation. That is water is lost as a by product
What occurs during denaturation?
Proteins loose their structure due to high temp or pH, due to hydrogen bonds being broken. Cross linking may occur causing irreversible changes
What is a proteins primary structure?
The sequence of amino acids in its polypeptide chain
What is the secondary structure of a protein?
The patterns (bending and folding) that occur due to interactions between nearby amino acids
What are 2 kinds of secondary structures?
Alpha helix or beta pleated sheets
What is a proteins tertiary structure?
The overall 3D shape of the protein that forms
What does tertiary structure determine?
The overall shape and hence function of a protein
What is quaternary structure?
The amount of polypeptide chains present in a protein
