Table of Contents
- 1 What is the possible number of different combinations of a 20 amino acid long polypeptide that can be formed in any living cell?
- 2 How many different protein sequences are possible?
- 3 How many different combinations of 20 amino acids are there?
- 4 How many different proteins are there in a cell?
- 5 How do you determine the quaternary structure of a protein?
- 6 How many different sequences of 3 amino acids are possible?
What is the possible number of different combinations of a 20 amino acid long polypeptide that can be formed in any living cell?
Since each of the 20 amino acids is chemically distinct and each can, in principle, occur at any position in a protein chain, there are 20 × 20 × 20 × 20 = 160,000 different possible polypeptide chains four amino acids long, or 20n different possible polypeptide chains n amino acids long.
How many different protein sequences are possible?
Studies of the protein universe as it exists today began with the first determination of a protein sequence by Sanger in 1952 (2). Now, there are almost 8 million sequences in a nonredundant (NR) database of protein sequences, including the complete genomes of ≈1,800 different species.
How is protein structure calculated?
Several methods are currently used to determine the structure of a protein, including X-ray crystallography, NMR spectroscopy, and electron microscopy. Each method has advantages and disadvantages. In each of these methods, the scientist uses many pieces of information to create the final atomic model.
How many different peptide configurations are possible for three different amino acids?
6 different constitutions
A tripeptide composed of three different amino acids can be made in 6 different constitutions, and the tetrapeptide shown above (composed of four different amino acids) would have 24 constitutional isomers.
How many different combinations of 20 amino acids are there?
Thus, the smallest combination of four bases that could encode all 20 amino acids would be a triplet code. However, a triplet code produces 64 (43 = 64) possible combinations, or codons.
How many different proteins are there in a cell?
A cell holds 42 million protein molecules, scientists reveal. Summary: Scientists have finally put their finger on how many protein molecules there are in a cell, ending decades of guesswork and clearing the way for further research on how protein abundance affects health of an organism.
How many combination of proteins are possible if the sequences are 3 in length?
Choosing the Amino Acids If you play with the letters A, U, G and C and rearrange them into groups of three, you’ll find that there are 64 possible combinations with distinct order. Each group of three is known as a codon.
How do you determine the secondary structure of a protein?
The secondary structure of proteins is determined by the pattern of hydrogen bonding. A large number of server and tools are used to predict the secondary structure analysis.
How do you determine the quaternary structure of a protein?
The quaternary structure (QS) of a protein is determined by measuring its molecular weight in solution. The data have to be extracted from the literature, and they may be missing even for proteins that have a crystal structure reported in the Protein Data Bank (PDB).
How many different sequences of 3 amino acids are possible?
If you play with the letters A, U, G and C and rearrange them into groups of three, you’ll find that there are 64 possible combinations with distinct order. Each group of three is known as a codon. Scientists have developed a chart that allows you to see what amino acid a specific codon codes for.
How many different tripeptides are possible from 20 amino acids?
8,000
20 x 20 x 20 = 8,000.