Portage Biochem Module 6 Latest Update 2024- 2025 Actual Exam 200 Questions and 100% Verified Correct Answers Guaranteed A+
From the course and module information, where in a eukaryotic or prokaryotic cell, is
the DNA located? How about the RNA? - CORRECT ANSWER: DNA is located in the
nucleus of a eukaryotic cell or the nucleoid of a prokaryotic cell. RNA is found in the nucleus, on the ribosome, and in other parts of the cell.
How many hydrogen bonds form between A and T? - CORRECT ANSWER: Two
hydrogen bonds are formed between these two bases. G and C form three H-bonds.
Is the following a pyrimidine or purine? Provide the name and one-letter symbol. -
CORRECT ANSWER: Pyrimidine. It is thymine (T).
Is this molecule ribose or 2-deoxyribose? Briefly explain what structural information was
used to determine this. - CORRECT ANSWER: Ribose. This molecule contains an -OH
on carbon 2. 2-deoxyribose has an -H atom on the second carbon.
What characteristic makes purines and pyrimidine heterocyclic? - CORRECT ANSWER: Each has a ring with nitrogen in the ring instead of all carbon atoms in the ring.
What constitutes the backbone of DNA? - CORRECT ANSWER: In DNA, this consists
of the alternating deoxyribose and phosphate groups linked together through covalent bonds.
What function does cAMP perform in cells? - CORRECT ANSWER: cAMP is a
communication molecule in cellular signaling. It acts as a secondary messenger.
What interactions stabilize the DNA double helix? - CORRECT ANSWER: Hydrogen
bonds stabilize the helix. Each AT pair and form two hydrogen bonds, and each GC pair forms three hydrogens that stabilize the helix, permitting it to maintain this shape. 1 / 2
What is the difference between a nucleoside and nucleotide? - CORRECT ANSWER: A
nucleoside is formed from the covalent bonding of a base (purine or pyrimidine) to either ribose (RNA) or 2-deoxyribose (DNA). Nucleotides are built from a nitrogen-containing organic base, a monosaccharide, and phosphate.
What is the difference between thymine and uracil? - CORRECT ANSWER: These two
bases differ by a methyl group. Thymine has an extra methyl group on the ring.
What structural forms of DNA have a right-handed helix? Which form has a left-handed helix? - CORRECT ANSWER: The A- and B-forms are right-handed, while the Z-form is left-handed.
What type of RNA has a sequence that is complementary to DNA? - CORRECT
ANSWER: mRNA is complementary so that it can transmit the information to the
ribosome.
Which DNA and RNA bases contain a carbonyl group? - CORRECT ANSWER:
Guanine, cytosine, thymine, and uracil all contain C=O group attached to the rings.Adenine is the only base that does not.
Which has the largest molecular weight chains: mRNA, tRNA, or rRNA? - CORRECT
ANSWER: rRNA. These molecules make up ribosomes.
Which nucleic acid is single-stranded? - CORRECT ANSWER: RNA. RNA forms single
strands. (Particularly, this was noted in this module for tRNA.) DNA forms a double helix.
A major component of RNA but not DNA is:
- AMP
- GMP
- UMP
- CMP
- / 2