Question

83. Ions are not able to diffuse through the phospholipid membrane bilayer because ions are? a. insoluble in water b. too large c. charged d. hydrophobic e. branched 85. mRNA transcripts must be processed before transport out into the nucleus.

Which of the following lists all of the modifications made to a pre-mRNA transcript? a. removal of introns and splicing together of exons b. addition of a 5'-cap and Poly-A tail c. addition of introns d. addition of a 5'-cap, addition of a Poly-A tail, and removal of introns e. removal of introns

86. What attracts or directs the synthesis enzyme to the template in Translation? a. Start Codon b. 5'-cap c. Primer d. Promoter e. Poly-A Tail 92. Which of the following is the description for Catabolic Reactions? a. the energy of movement b. the breaking down of complex molecules into simpler ones c. energy converted from one form to another d. energy is neither created nor destroyed e. the linking of simple molecules to form complex molecules

93. Which of the following enzymes is NOT involved in DNA replication? a. Primase b. DNA Ligase c. DNA Polymerase d. Helicase e. Phosphatase

94. Hydrophobic interactions bring molecules together based on what? a. incorporation of water b. exclusion of water c. sharing of electrons d. interaction of oppositely charged molecules e. exclusion of oil 99. What is the "key" component that 'moves' when looking at metabolic reactions? a. Energy b. Carbohydrates c. Water d. Lipids e. Monosaccharides

Answer 1

83. (C) Charged

The charged molecules can not diffuse through the hydrophobic phospholipid bilayer because it is uncharged. And uncharged membrane repel charged molecules. Fir charged ions to go through membrane special ion channels are present in the membrane. These ion channels requirs energy in form of ATP to function.

85. (A)  Removal of introns and splicing together of exons

Introns are the non-coding region of the m,RNA which is not required for translation purpose. Introns are removed by post transcriptional modifications and exons are spliced. Exons are protein coding region of the mRNA. This whole machinary is called Spliceosome. Pre-mRNA already have 5'- cap and 3' Poly A tail.

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