Category - Definitions

Query - What definition best describes the term below?

Reversal

Category - Term Recognition

Query - What term does the description below refer to?

(Terms are shown on left, descriptions in middle, figures on right)

A-Form Helix | A right-handed helical structure of nucleic acids. Found in DNA fibers under conditions of low humidity, DNA-RNA hybrids, and duplex RNA. | Figure 4.15 | B-Form Helix | The predominant secondary structure of DNA in cells, consisting of a right-handed double-stranded helix, with antiparallel strands, complementary, hydrogen-bonded base pairs, and 10 bases per turn of the helix. Also has a major and minor groove. | Figure 4.15, Figure 4.16 | Base pairs | Refers to the fact that, in a helical nucleic acid, bases on each strand are always paired in a complementary fashion - A pairs with U or T and vice versa; G pairs with C and vice versa. Stabilized by hydrogen bonds. | Figure 4.10 | Complementarity | With respect to nucleic acids, refers to the fact that bases are always paired in like fashion - A pairs with U or T and vice versa; G pairs with C and vice versa. This arrangement puts bulkier purines paired with smaller pyrimidines, keeping the DNA from bulging in places. |  | Cooperative transitions | With respect to melting of nucleic acid sequence, the observation the process occurs over a very short temperature range. Melting does not occur bit by bit. |  | Denaturation | A process which results in loss of secondary and/or tertiary structure of a linear polymer, such as DNA or protein. |  | Genome | The total genetic information for an organism |  | H-DNA | A triple helical form of DNA with Hoogsteen base pairs. Structure favored when one strand is all purines and complementary strand is all pyrimidines. | Figure 4.30 | Linking number | The total number of times the two strands of a DNA helix cross each other by means of either twist or writhe; this equals the number of times the two strands are interlinked. It reflects both the winding of the native DNA helix and the presence of any supercoiling. | Figure 4.24 | mRNA | Made complementary to a portion of a DNA molecule by an RNA polymerase. **** carries the nucleotide sequence from the DNA to the ribosomes where translation occurs. | Figure 4.22 | Nucleoside | Composed of a sugar and a purine or pyrimidine base | Figure 4.3 | Nucleotide | The monomeric units of nucleic acids. Composed of at least one phosphate, a sugar, and a purine or pyrimidine base | Figure 4.3 | Palindrome | With respect to DNA, a segment in which the sequence is the same on one strand read right to left as on the complementary strand read left to right; thus, a back-to-back pair of inverted repeats. | Figure 4.28 | Phosphodiester bonds | The covalent bonds holding the backbone of nucleic acids together. | Figure 4.1 | Polymerases | Enzyme catalysts responsible for making the nucleic acid polymers. |  | Primary structure | For a nucleic acid, refers to the sequence of bases within it. |  | Purine | One of two types of bases in nucleic acids. Adenine and guanine are examples. | Figure 4.2 | Pyrimidine | One of two types of bases in nucleic acids. Cytosine, uracil, and thymine are examples. | Figure 4.2 | Random coil | Refers to a linear polymer that has no secondary or tertiary structure, but instead is wholly flexible with a randomly varying geometry. This is the state of a denatured protein or nucleic acid. | Figure 4.19 | Ribosomes | Complexes of protein and rRNA that perform translation of nucleic acid sequence into amino acid sequence for protein synthesis. | Figure 4.22 | rRNA | A type of RNA that is a component of ribosomes and plays a structural and catalytic role in the process of translation (making protein from nucleic acid sequence). |  | Secondary Structure | Local folding of the backbone of a linear polymer to form a regular, repeating structure. The B- and Z-forms of the DNA helix are examples. |  | Semi-conservative replication | The mechanism by which DNA replication proceeds in cells in which the two strands of a parent DNA are each replicated and end up being paired to one new daughter strand each in the progeny DNAs. |  | Supercoiling | For a DNA double helix, a structure that arises when turns of the two strands around each other either exceed or are fewer than the number of turns in the most stable helical conformation. Only a helix that is circular or else fixed at both ends can support this. | Figure 4.24 | Superhelix density | A measure of the superhelicity of a DNA molecule. It is equal to the change in linking number caused by the introduction of supercoiling divided by the linking number the DNA molecule would have in its relaxed state. |  | Tautomers | Structural isomers that differ in the location of their hydrogens and double bonds. Bases in nucleic acids can assume these different forms. | Figure 4.4 | Tertiary Structure | Large-scale folding structure in a linear polymer that is at a higher order than secondary structure. |  | Topoisomerases | Enzymes that cause changes in the linking number of a DNA by introducing or removing twists. |  | Transcription | The synthesis of an RNA molecule complementary to a DNA strand; the information encoded in the base sequence of the DNA is thus copied into the RNA version of the same code. | Figure 4.21, Figure 4.23 | Translation | The synthesis of a polypeptide under the direction of an mRNA, so that the nucleotide sequence of the mRNA is converted into the amino acid sequence of the protein. | Figure 4.23 | tRNA | Molecules that are the basis of translating the genetic code. One end of the these molecules contains a three nucleotide sequence called the anticodon loop that is complementary to the codon of the mRNA. The other end of these molecules is covalently attached to a specific amino acid. | Figure 4.22 | Twisting | With respect to a DNA double helix, the total number of times the two strands of the helix cross over each other, excluding writhing. It is a measure of how tightly the helix is wound. | Figure 4.24 | Writhing | With respect to a supercoiled DNA helix, the number of times the helix as a whole crosses over itself - that is, the number of superhelical turns that are present. | Figure 4.24 | Z-DNA | A left-handed helical form of DNA. Notable features include purines in the "syn" configuration. Forms with alternating units of pyrimidines and purines in each strand. | Figure 4.26 | Chargaff's rule | An early observation about the chemical nature of DNA that later gave clues to Watson and Crick about the structure of DNA. Essentially, it states that the amount of guanine in DNA is the same as cytosine and the amount of adenine is the same as the amount of thymine (or G=C, A=T). |

Category - Structures

Query - What is the structure of the molecule below?

Reversal

Category - Molecules

Query - What is the name of the molecule with the structure below?

(molecule name on left, structure on right)

Adenine - structure

Guanine - structure

Cytosine - structure

Uracil - structure

Thymine - structure

Adenosine - structure

Guanosine - structure

Cytidine - structure

Uridine - structure

Thymidine - structure

Ribose - structure

Deoxyribose - structure

Ribonucleoside - ribose + base

Deoxyribonucloside - structure

Nucleoside - structure

Nucleoside monophosphate - structure

Nucleoside diphosphate - structure

Nucleoside triphosphate - structure

Nucleotide - structure

Deoxyribonucleotide - structure

Ribonucleotide - structure

Nucleoside triphosphate - structure

Nucleoside monophosphate - structure

Category - General

Query - What discovery is the person below credited with?

Reversal

Category - General

Query - Which person(s) is/are credited with the following discovery?

(Person on left, discovery on right)

Miescher - Discovered DNA

Avery, MacLeod, McCarty - Pathogenicity transferred with DNA

Hershey and Chase - DNA alone can cause synthesis of T2 bacteriophage

Watson and Crick - Structure of DNA double helix

Franklin - X-Ray diffraction pattern used by Watson and Crick

Meselson-Stahl - DNA replication is semi-conservative