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Download CHEM 210 Biochemistry Module 6 Exam|| Portage Learning Questions and 100% Verified Answers and more Exams Molecular biology in PDF only on Docsity!
In DNA, adenine always pairs with - Thymine - Guanine - Uracil - Cytosine - Correct Answer - Thymine DNA is built from which of the following? - Nucleosides - Genes - Purines - Nucleotide - Codons - Correct Answer - Nucleotide The double helix of DNA is stabilized mainly by - lonic bonds - Covalent bonds - lon-dipole bonds - Hydrogen bonds - Hydrogen covalent bonds - Correct Answer - Hydrogen bonds Which of the following pentose sugars is a constituent of DNA? - Xylose - Ribitol - 2-deoxyribose - Arabinose - Ribose - Correct Answer - 2-deoxyribose Pyrimidines have ring(s), (each) containing nitrogen(s), whereas purines have ring(s), (each) containing nitrogen(s). “Lith =1;222:2 22327 1:2 - Guanine-Adenine - Cytosine-Uracil - Correct Answer - Adenine- Thymine How many hydrogen bonds are made between G and its complementary nucleotide? - 5 - Correct Answer - 3 The base sequence along one strand of DNA of 5'-GCATGAGCC-3'. What is the sequence of the complementary strand of DNA? - 5-CTAGTCCGC-3' - 3'-CGTACTCGG-S' - 3'-CTAGTCCGC-S' - 3'-CAGTCAGCT-5' - 5-CTGACTACG-3' - Correct Answer - 3'-CGTACTCGG-5' Which of the following types of RNA functions to carry genetic information from the DNA to ribosome? - mRNA -gRNA - TRNA - snRNA - tRNA - Correct Answer - mRNA Which of the following is the set of three sequential nucleotides that encodes for a particular amino acid? - Codon - Anticodon - Allele + Gene - Chromosome - Correct Answer - Codon A type of DNA that has a right-handed helix is the - CAMP - GGG - Correct Answer - FAD rRNA makes up about percent of ribosomes. - 35 - 65 - 20 - 90 - 15 - Correct Answer - 65 The conclusion that G and C are present in DNA in equimolar is credited to - James Watson - Francis Crick - Erwin Chargaff - Both A and B - None of the above - Correct Answer - Erwin Chargaff The order of nucleotides in DNA is written toc CtoN - 3' to 5! -§'to3' - Both C and D - Correct Answer - 5' to 3" In the Watson-Crick model for the double helix, which statement is NOT true? - The two strands run anti-parallel to one another - The base-pairing occurs on the inside of the double helix. - The double helix (B form) is right-handed. - Two equally sized grooves that run up the sides of the helix. - The two strands have complementary sequences. - Correct Answer - Two equally sized grooves that run up the sides of the helix. In the tRNA, below, the amino acid is attached to which position? - Correct Answer A Scientists say that two DNA strands are complementary. Briefly describe what is meant by complementary Show one example in your response. - Correct Answer The nucleotide sequences of complementary strands are such that, whenever an A occurs in one strand, there is a T in the other strand with which it can form a hydrogen-bonded base pair. Whenever a C occurs in one strand, a G occurs in the other. A is the base that is complementary to T, and C is the base complementary to G. Briefly describe how noncovalent interactions contribute to the three- dimensional shapes and structures of RNA molecules. - Correct Answer Hydrogen bonding in regions of complementarity within an RNA chain can result in the formation of a structure. If no complementary regions exist then an unstructured area will exist within the RNA. In one sentence, identify the most noticeable difference between the A- form of DNA and the Z form of DNA. - Correct Answer The Z-form of DNA is left handed while the A-form of DNA is right handed. In nucleic acid chemistry, compounds that contain an organic nitrogen- containing base, a sugar, and phosphate group are called A Two purines found in DNA in are B and B A pyrimidine found in all RNA but notin DNAis_ CO In DNA, the pair ==D__is held together by three hydrogen bonds. In DNA, the pentose iE serves as the monosaccharides. - Correct Answer A) nucleotides B) adenine and guanine C) uracil D)C-G E) 2-deoxyribose The monomers of RNA nucleic acids, called nucleotides, consist of three parts. What are those three parts? - Correct Answer A base, monosaccharide, and phosphoric acid 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. a prokaryotic cell. RNA is found in the nucleus, on the ribosome, and in other parts of the cell. 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. What constitutes the backbone of DNA? - Correct Answer In DNA, this consists of the alternating deoxyribose and phosphate groups linked together through covalent bonds. 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. 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. 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. 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 has the largest molecular weight chains: mRNA, tRNA, or rRNA? - Correct Answer rRNA. These molecules make up ribosomes. 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 function does cAMP perform in cells? - Correct Answer cAMP is a communication molecule in cellular signaling. It acts as a secondary messenger. Which of the following pentose sugars is a constituent of DNA? Xylose Ribitol 2-deoxyribose Arabinose Ribose - Correct Answer 2-deoxyribose Pyrimidines have ring(s), (each) containing nitrogen(s), whereas purines have ring(s), (each) containing nitrogen(s). - Correct Answer pyrimidines have 1 ring, each containing 2 nitrogens, purines have 2 rings, each containing 2 nitrogens. Pyrimidines are which 2 bases and which two are Purines? - Correct Answer Pyrimidines: Cytosine (C) and Thymine (T) Purines: Guanine (G) and Adenine (A) Look at SS for what each base looks like - Correct Answer see SS Which of the following nucleic acids is responsible for USING the encoded genetic information to produce of proteins found in living organisms? Peptide nucleic acid Ribonucleic acid Ribitol nucleic acid Deoxyribonucleic acid Glycerol nucleic acid - Correct Answer Ribonucleic acid Identify the complementary bases from the following. Adenine-Cytosine Adenine- Thymine Guanine-Thymine Guanine-Adenine Cytosine-Uracil - Correct Answer Adenine- Thymine How many hydrogen bonds are made between G and its complementary nucleotide? - Correct Answer 3 hydrogen bonds between G-C t-form X-Form B-form L-form Z-form - Correct Answer A and B forms Which of the following is a second messenger in cells? FAD cAMP AMP dATP UTP - Correct Answer cAMP Which of the following acts a coenzyme? FAD ATP AMP cAMP GGG - Correct Answer FAD rRNA makes up about percent of ribosomes. - Correct Answer 65% The conclusion that G and C are present in DNA in equimolar is credited to what historical figure? James Watson Francis Crick Erwin Chargaff Both A and B None of the above - Correct Answer Erwin Chargaff The order of nucleotides in DNA is written to CC toN atas 5' to 3 Both C and D - Correct Answer 5' to 3' 
