(a)
Answer
Invariant residues are the amino acids that are identical in all homologue in the protein and they are conserved in all species and are necessary for the structure and functioning of the protein which cannot be replaced by other amino acid residues. In both the sequences of the heat shock protein Hsp 90 the invariant amino acid residues are Y(1), F(7), and R (9).
(b)
Answer
At position 4 and 9 amino acids are limited with Lysine (K) and Arginine (R) respectively which are positively charged. K is more common at position 4 in both the sequences while R is an invariant amino acid residue at position 9 in both sequences.
(c)
Answer
At positions 5 and 10 the substitutions are restricted with amino acid E (Glutamic acid) which has a negative side chain. At both positions the amino acid E is more common and predominant.
(d)
Answer
The position at which any amino acid can be present is position 2. The amino acid which is most common at this position is S (Serine).
Sequence Comparisons Proteins called molecular chaperones (described in Chapter 4) assist in the process of protein...
1) Select all that apply. Globular proteins: a)are found in hair and wool. b)include myoglobin and collagen. c)are usually water soluble. d)aggregate in aqueous media. e)are often made of β-pleated sheet and α-helix sections wrapped into compact structures. 2) Select all that apply. The Bohr effect: a)depends on the atomic orbital structure of hydrogen. b)can be summarized as a reduction in the oxygen affinity of hemoglobin with decreasing pH. c)is explained by the protonation of key amino acids, including the...
1. Amino acids are considered to be either hydrophobic or hydrophilic as described by the relative polarity of their side chain. Consider a folded protein in an aqueous environment; where would the hydrophobic amino acids likely be found? -Tucked away in the middle of the folded protein -Randomly distributed throughout the protein -Exposed on the exterior surface of the folded protein 2. All proteins exhibit a primary, secondary, and tertiary structure, but not all proteins exhibit a quaternary structure. Describe...
The signal sequence found in proteins that are sorted to the matrix of the mitochondrion is? A. an N-terminal amphiphilic α-helix that is cleaved from the protein by a signal peptidase in the matrix of the mitochondrion B. an N-terminal amphiphilic α-helix that is not removed from the protein C. an N-terminal sequence of at least eight hydrophobic residues that is not removed from the protein D. five adjacent (+)-charged amino acids found anywhere within the protein sequence; this signal...
A chain GIVEQCCASVCSLYQLENYCN B chain FVNQHLCGSHLVEALYLVCGERGFFYTPKA Shown above is the amino acid sequence of the hormone insulin. This structure was determined by Frederick Sanger and his coworkers. Most of this work is described in a series of articles published in the Biochemical Journal from 1945 to 1955. When Sanger and colleagues began their work in 1945, it was known that insulin was a small protein consisting of two or four polypeptide chains linked by disulfide bonds. Sanger and his coworkers...
Biochemistry Styrer Chapter 3 Problem 1. 1. Valuable reagents. The following reagents are often usedin protein chemistry: CNBr Trypsin Urea Performic acid Mercaptoethanol 6 N HCl Chymotrypsin Phenyl isothiocyanate Which one is the best suited for accomplishing each of thefollowing tasks? (a) Determination of the amino acid sequence of a small peptide. (b) Reversible denaturation of a protein devoid of disulfidebonds. Which additional reagent would you need if disulfide bonds were present? (c) Hydrolysis of peptide bonds on the carboxyl...
14. Recombinant MBP-, GST- or GFP- fusion proteins are expressed in bacteria not only for affinity chromatography but also to ___________. A. overexpress the proteins in bacteria B. to reduce toxicity of the foreign proteins C. for proper folding and keeping the proteins soluble D. to trace the cytological location of the foreign proteins 15. You have constructed an insulin-GST fusion protein and expressed it in E. coli. You want to separate the recombinant...
Protein kinases can A) Inactivate enzymes by dephosphorylating them B) Activate enzymes by phosphorylating them C) Cleave proteins after Tyr, Ser, or Thr residues D) Contain a catalytic triad to cut peptide bonds Peanut oil contains a high percentage of monounsaturated fatty acids whereas vegetable oil contains a high percentage of polyunsaturated fatty acids. During a cold spell, the peanut oil freezes whereas the vegetable oil remains liquid. Explain why. Predict which one of the following organisms will have the...
DNA, Genes and Protein Synthesis Activity 13: Protein Synthesis is the process by which cells produce (synthesize) proteins. An overview of the process is shown in model 2 (below). Gone 2 Gene 1 Gene 3 DNA strand3 TRANSLATION Protein Trp Gly Model 2 ACTIVITY and QUESTIONS 1. Based on the information you can gather from model 1 complete the following sentences: a. The nucleotide Adenine (A) always pairs with the nucleotide b. The nucleotide Guanine (G) always pairs with the...
(18 pts) Answer True or False for each of the following questions (a) An amino acid is in the zwitterionic form only if the pll is well below 7 (b) Salting out takes advantage of the fact that the solubility of proteins varies with concentration. (c) Proteins usually consists of amino acids of both L-isomers (d) Essentially all a-helices found in proteins are left-handed globular protein is thermodynamically the most stable structure. ( Isoclectric focusing can be used to separate...
Which of the following is an acceptable term/name used for a molecule in which two carbons of glycerol are attached to fatty acid chains, and the third carbon of glycerol is attached to a phosphate group? C sphingomyelin C phospholipid C phosphosteroid C triacylglycerol A nucleotide is different from a nucleoside because a nucleotide has C a ribose sugar. C a deoxyribose sugar. C at least one phosphate group. nitrogen-containing base. Most types of molecules in the cell have asymmetric...