1.Primary protein structure determines which of the following additional levels of protein organization:
a. 2°
b. 3°
c.2°,3°,4°
d. 4°
2.Which of the following pairs is mismatched:
a) Glycocalyx - may be capsule or slime layer
b) Pili- Reproduction
c) Cell wall-protective, determines shape, prevents from bursting
d) Flagella, pili fimbriae-surface structures of bacterial cell
3.Which is the highest structure organization found in all enzymes:
a. 1°
b. 2°
c. 3°
d. 4°
4.Which is mismatched pair:
a) Capsule- thick and tough glycocalyx
b) Slime layer-Joose glycocalyx
c) Pili - motility organ
d) Bacterial cells, -motile or non-motile
Answers
Explanation:
Egg whites contain large amounts of proteins called albumins, and the albumins normally have a specific 3D shape, thanks to bonds formed between different amino acids in the protein. Heating causes these bonds to break and exposes hydrophobic (water-hating) amino acids usually kept on the inside of the protein^{1,2}
1,2
start superscript, 1, comma, 2, end superscript. The hydrophobic amino acids, trying to get away from the water surrounding them in the egg white, will stick to one another, forming a protein network that gives the egg white structure while turning it white and opaque. Ta-da! Thank you, protein denaturation, for another delicious breakfast.
As we mentioned in the last article on proteins and amino acids, the shape of a protein is very important to its function. To understand how a protein gets its final shape or conformation, we need to understand the four levels of protein structure: primary, secondary, tertiary, and quaternary.
Primary structure
The simplest level of protein structure, primary structure, is simply the sequence of amino acids in a polypeptide chain. For example, the hormone insulin has two polypeptide chains, A and B, shown in diagram below. (The insulin molecule shown here is cow insulin, although its structure is similar to that of human insulin.) Each chain has its own set of amino acids, assembled in a particular order. For instance, the sequence of the A chain starts with glycine at the N-terminus and ends with asparagine at the C-terminus, and is different from the sequence of the B chain.