I really need help with the last few questions 3, 4, and 4a The picture below sh
ID: 55790 • Letter: I
Question
I really need help with the last few questions 3, 4, and 4a
The picture below shows a transmembrane protein composed of several alpha-helical polypeptides. This protein works as a earner of potassium ions (potassium ions have a positive charge). Circle the group number (1,2, 3) to indicate which type of the amino acids shown below may be present in the parts of the protein labeled A, B and C (note multiple answers are possible for each) You compare the amino acid sequences of an enzyme from yeast and human cells whose function is to break apart the disaccharide fructose. The amino acid sequences of these two enzymes are quite different. However, when you examine the 3-dimensional conformation of these two enzymes, you find that they have almost identical conformations. How is it possible for two proteins to have very different amino acid sequences and still fold the same way? Spider silk has received a lot of attention in recent years because it is composed of a protein with tremendous tensile strength, and this property has been exploited to make modern ballistic equipment such as bulletproof vests. The primary amino acid sequence of spider silk is enriched in highly repetitive glycine- and alanine-containing segments. Alanine-rich segments form beta -sheets. What type of structure is a beta-sheet (e.g. primary, secondary, tertiary or quaternary)?Explanation / Answer
3. Presence of similar amino acids at the active site makes the protein fold in a similar way. Though the amino acids are not same exactly, they are similar in nature. The same kind of amino acids i.e., hydrophobic in nature or hydrophilic in nature, produce same kind of foldings in the enzyme, thus producing almost identical 3-dimensional conformation.
4a. Beta sheets are secondary structures.