Term
| What are the three components of a nucleotide? |
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Definition
| A 5' carbon sugar, phosphate group, and a nitrogenous base |
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Term
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Definition
| a class of small, nitrogen-containing, double-ringed bases (guanine and adenine) found in nucleotides |
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Term
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Definition
| a class of small, nitrogen-containing, single-ringed bases (cytosine, uracil, and thymine) found in nucleotides |
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Term
| Explain the difference between ribose and deoxyribose |
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Definition
| On the 2' carbon sugar (in ribose) there is a hydroxyl group where as in deoxyribose there is just a hydrogen |
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Term
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Definition
| a nucleic acid composed of ribonucleotides that usually is single stranded. Functions include structural components of ribosomes (rRNA), transporters of amino acids (tRNA), and messages of the DNA code required for protein synthesis (mRNA) |
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Term
| DNA (deoxyribonucleic acid) |
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Definition
| a nucleic acid composed of deoxyribonucleotides that carry the genetic information of a cell. Generally occurs as two intertwined strands, but these can be separated |
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Term
| Describe the structure of DNA. What is its shape? What is meant by the term, "sugar phosphate backbone?" What is meant by the term, "anti-parallel?" |
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Definition
-Double helix
-Sugar-phosphate backbone means the phosphate group and the deoxyribonucleic acid.
-Anti-parallel means the 5' and 3' are on the south side and another 3' and 5' on the north side |
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Term
| What are the dimensions (measurements) of a DNA molecule? |
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Definition
-length of one complete turn of helix is 3.4 nm (10 rungs per turn)
-width of helix is 2.0 nm
-the distance between the bases is 0.34 nm |
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Term
| What type of bond connects the nucleotides within a single strand of RNA and DNA? |
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Definition
| Covalent bond (phosphodiester bond) |
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Term
| What type of bond is important for holding the two strands of a DNA molecule together? |
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Definition
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Term
| If a DNA molecule contains 16% adenine, what percentage of thymine does it contain? What percentage is cytosine? Guanine? |
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Definition
-16% thymine
-34% cytosine and guanine |
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Term
| Describe how DNA is copied. |
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Definition
-Strand separation: DNA strands separate when hydrogen bonds between complementary base pairs are broken
-Base pairings: Each strand of DNA can serve as a template for the formation of a new strand. Free nucleotides attach to 3’ ends according to complementary base pairing
-Polymerization: When the new strands polymerize to form a sugar-phosphate backbone, secondary structure is restored. |
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Term
| Explain how a hairpin structure can form in a molecule of RNA |
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Definition
| If the section where the fold occurs includes unpaired bases, then the stem-and-loop configuration result in this type of secondary structure |
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Term
| Why is RNA more reactive and unstable than DNA |
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Definition
| Because of that hydroxyl group on the 2' carbon sugar |
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Term
| How are DNA molecules of different lengths (sizes) separated using DNA electrophoresis? What components are necessary for this technique? |
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Definition
| Molecules that are smaller and more highly charged run farther than molecules that are larger and less highly charged; a gel and charge (battery) are needed for this technique |
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Term
| What is an STR site? How is it useful for DNA fingerprinting? |
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Definition
| A STR site is a short tandem report, and it is useful because relatives share some alleles (bands), but unrelated individuals share few if any; so it explains relationship and comparison |
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Term
| For DNA fingerprinting, why is it important to test more than one STR site? |
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Definition
| There is the possibility that they do have the same DNA sequence at some sites, so multiple sites need to be tested to make sure that the results are correct |
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Term
| What are the four nitrogenous bases found in RNA? |
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Definition
| Adenine, uracil, guanine, cytosine (A,U,G,C) |
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Term
| What determines the primary structure of a DNA molecule? |
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Definition
| The sequence of deoxyribonucleotides |
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Term
| DNA attains a secondary structure when hydrogen bonds form between the nitrogenous bases called purines and pyrimidines. What are the complementary base pairs that form in DNA? |
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Definition
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Term
| Which of the following rules apply to the synthesis of nucleic acids? |
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Definition
| Complementary pairing between bases is required for copying nucleic acids |
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Term
| Nucleic acids are directional, meaning that there are two different ends. What functional groups define the two different ends of a DNA strand? |
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Definition
| One end has a free phosphate group on the 5'carbon; the other end has a free hydroxyl group bonded to the 3' carbon |
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Term
| What is responsible for the increased stability of DNA compared to RNA? |
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Definition
| DNA is a more stable molecule than RNA because it lacks a hydroxyl group on the 2' carbon and is therefore more resistant to cleavage, and because the two sugar-phosphate backbones are held together by many hydrogen bonds between nitrogenous bases |
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