07. MicroRNAs a. bind to sequences in untranslated regions of mRNAs to INCREASE
ID: 281287 • Letter: 0
Question
07. MicroRNAs a. bind to sequences in untranslated regions of mRNAs to INCREASE their degradation. b. bind to sequences in untranslated regions of mRNAs to DECREASE their degradation, c. bind to sequences in coding regions of mRNAs to INCREASE their degradation. d. bind to sequences in coding regions of mRNAs to DECREASE their degradation. e. are translated to make proteins that regulate mRNA stability. 08. The structure of a-hellces and B-pleated sheets in polypeptides is stablized by what type of bonds a. hydrogen b. covalent c. van der Waals d. ionic e. disulfide 09. One eukaryotic gene can code for more than one polypeptide due to a. transcription. b. alternate splicing. c. transposition. d. hybridization. e. exon shuffling. 10. Amino acids are can be categorized by the a. degree of polarity of their carboxyl groups. b. degree of polarity of their amino groups. c. characteristics of their side chains d. number of disulfide bridges they can form. e. number of peptide bonds they can form. II. Which of the following is the strongest interaction? a. hydrogen bond b. hydrophobic effect c. ionic bond d. glycosidic bond e. van der Woals interaction 12. What level of structure in proteins is held together by interactions between amino acid R groups? a. primary structure b. secondary structure c tertiary structure d. quaternary structure e. Both c and d are correct answers.Explanation / Answer
Answer-7: Correct answer is option (a)
Explaination- mi-RNA tend to regulate the post-transcriptional gene expression by binding to 3' end of untranslated region of an m-RNA. It causes the inhibition of protein production by increasing the degradation of target m-RNA or sometimes by gene silencing.
Answer-8: Correct answer is option (a)
Explaination- Secondary structure of protein is formed when there is an interaction between a carbonyl group and amino group of amino acids by the weak hydrogen bonds. Due to this arrangement, R groups can be spirally arranged to form Alpha helix , or the groups can be arranged sideways to form Beta-pleated structure.
Answer-9: Correct answer is option (b)
Explaination- In alternative splicing, polypeptides formed can be small or big depending upon which intron is removed or which exons are joined. Based upon the sequence of exons joined, that particular type of polypeptide is formed to give the differencial protein product.
Answer-10: Correct answer is option (c)
Explaination- There are plenty of side chains or R groups of amino acid, which is a reason for their diversity. R groups can be aromatic, polar, non,polar, sulphur containing, imidazole ring, etc.
Answer-11: Correct answer is option (d)
Explaination- Glycosidic bonds are a type of covalent bonds. And, covalent bonds are stronger over ionic bonds. This is because, covalent bonds are bonds due to sharing of electrons, whereas, ionic bond is formed due to donation of electrons from an electro-positive atom to an electro-negative atom so that they complete their valenced shell. Moreover, covalent bonds are further categorized into single, double and triple bonds, which contibutes for their higher bond dissociation enthalpy. Thus, Glycosidic bond (covalent) is stronger among rest of the bonds!
Answer-12: Correct answer is option (c)
Explaination- Whenever there is an interaction between R groups of amino acids, it leads to the formation of tertiary structure. Tertiary structure is formed due tot folding of a polypeptide. Whereas, quaternary structure of protein is formed when there are more than 2 polypeptides involved in a protein structure, and each individual polypertide is referred to as a subunit of a protein.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.