Proteins Flashcards
What are polypeptides and how are they made?
Polypeptides are chains of amino acids and they are made by linking together amino acids by condensation reactions. This happens in ribosomes in a process called translation
What is the main component(s) of proteins? And how many of these components can be present in a protein?
Polypeptides are the main component in proteins and in most proteins remain the only component. A protein can be made of one or more polypeptides
What is involved and happens in the formation of polypeptides? (bond and reaction)
In the condensation reaction, the amine group of amino acid and the carboxyl group of another are involved and water is eliminated in the process. The bond formed between the amino acids is called a peptide bond
What are some identical structural features shared by all amino acids?
Each amino acids that used by ribosomes to make polypeptides have a central atom carbon, bonded to an amine group on one of its side and a carboxyl group of the opposite side. One end of the central carbon atom is covalently bonded to a hydrogen, and opposite to this is a R group which is different for each amino acid.
How many types of amino acids are used by ribosomes to make polypeptides? Despite identical structural features, what makes these amino acids different from each other or diverse?
There are 20 different amino acids used by ribosomes to make polypeptides. These 20 amino acids are very diverse from each other due to the differences in their R group that gives them their character and a different chemical composition.
What is the consequence of the diversity of amino acids?
As the 20 different amino acids have differences in their R groups which makes each of them chemically diverse, this repertoire of R groups make it possible for living organisms to make and use an amazingly wide range of proteins.
There are some proteins that contain amino acids that do not fall in the repertoire of the fixed number of different amino acids stated earlier. Why is it so? Provide an example.
This is because in most cases one of the twenty amino acids is modified after a polypeptide has been synthesized. An example of such a modification of amino acids is collagen. The collagen polypeptide contains proline at many positions of the polypeptide chain, but at some positions, it is converted to hydroxyproline, which makes collagen more stable.
What is the classification of amino acids?
There are universally 20 different amino acids, which means various R groups of different chemical properties. R groups can have diverse chemical properties such as polar and hydrophilic, non-polar hence hydrophobic, positive charge, negative charge structural differences such as rings or no rings
How can ribosomes form polypeptides containing amino acids of any sequence?
Ribosomes link amino acids one at a time until a polypeptide is fully formed. Ribosomes can form peptides bonds between any pair of amino acids, and therefore there can be endless possible sequences of amino acids
What is the general formula for finding the number of possible sequences of animo acids?
20 amino acids are there, and any of these amino acids can be used to form the polypeptide chain, and the number of amino acids that can be there is a chain can be any; the formula is this 20 to the power of n which denotes number of animo acidds in consideration.
What determines the type of polypeptide formed when ribosomes link together amino acids?
The information for the coding the amino acid sequence is stored in the base sequences of genes.
How are the sequences of amino acids to form a polypeptide made by the controller of this sequence?
The sequemce of amino acid is made by using the universal genetic code. Three bases of the gene are needed to code for one amino acid
