Which of these is an example of a base analog?
Examples of base analogues include 5-bromouracil, 2-aminopurine, 6-mercaptopurine, and acycloguanosine (Figure 21.9). Since 5-bromouracil can pair with either adenine or guanine, it also affects base pairing during DNA replication, which leads to mutations.
Which of the following is a mutagen?
Examples of mutagens include radioactive substances, X-rays, ultraviolet radiation, and certain chemicals. Complete answer: Mutagen is any physical or chemical agent that changes the genetic material usually DNA of an organism and thus increases the frequency of mutations above the natural level.
Which is a frameshift mutation?
A frameshift mutation is a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read. Therefore, frameshift mutations result in abnormal protein products with an incorrect amino acid sequence that can be either longer or shorter than the normal protein.
What are the consequences of having pyrimidine dimers in DNA?
What are the consequences of having pyrimidine dimers in DNA? These dimers distort the DNA structure and result in errors during DNA replication. They form an extra phosphodiester bond between them. They prevent the transcription of the DNA into RNA.
What is a DNA dimer?
Pyrimidine dimers are molecular lesions formed from thymine or cytosine bases in DNA via photochemical reactions. Ultraviolet light (UV) induces the formation of covalent linkages between consecutive bases along the nucleotide chain in the vicinity of their carbon–carbon double bonds.
What does pyrimidine mean?
(py-RIH-mih-deen) One of two chemical compounds that cells use to make the building blocks of DNA and RNA. Examples of pyrimidines are cytosine, thymine, and uracil. Cytosine and thymine are used to make DNA and cytosine and uracil are used to make RNA.
What are examples of pyrimidine?
The pyrimidines in DNA are cytosine and thymine; in RNA, they are cytosine and uracil. Purines are larger than pyrimidines because they have a two-ring structure while pyrimidines only have a single ring.
What is pyrimidine used for?
Pyrimidine ring is found in Vitamins like thiamine, riboflavinand folic acid. Pyrimidine derivatives have been found to be possessed diverse biological activities including antiviral, anticancer, antifungal, antimalarial, sedative, hypnotic, anticonvulsant, anthelmintics and antithyroid activities.
What does a pyrimidine consist of?
Pyrimidine is a simple aromatic ring composed of two nitrogen atoms and four carbon atoms, with hydrogen atoms attached to each carbon.
What are the 3 pyrimidine bases?
In nucleic acids, three types of nucleobases are pyrimidine derivatives: cytosine (C), thymine (T), and uracil (U).
Which of the following is a pyrimidine base?
The most important biological substituted pyrimidines are cytosine, thymine, and uracil. Cytosine and thymine are the two major pyrimidine bases in DNA and base pair (see Watson–Crick Pairing) with guanine and adenine (see Purine Bases), respectively.
What are the two bases that are purines?
Nitrogenous bases present in the DNA can be grouped into two categories: purines (Adenine (A) and Guanine (G)), and pyrimidine (Cytosine (C) and Thymine (T)).
What are purines examples?
Examples of structures of purines: (1) adenine; (2) hypoxanthine; (3) guanine (G). Pyrimidines: (4) uracil; (5) cytosine (C); (6) thymine (T). Nucleosides: (7) adenosine (A); (8) uridine (U). Nucleotides: (9) 3′,5′-cAMP; (10) adenosine 5′-triphosphate.
What are the purines bases?
The most important biological substituted purines are adenine and guanine, which are the major purine bases found in RNA and DNA. In DNA, guanine and adenine base pair (see Watson-Crick pairing) with cytosine and thymine (see pyrimidines) respectively.
How do you count purines?
The nucleotides are shown with standard numbering convention. The aromatic base atoms are numbered 1 through 9 for purines and 1 through 6 for pyrimidines. The ribose sugar is numbered 1′ through 5′.
How do you count base pairs?
Base pairs often are used to measure the size of an individual gene within a DNA molecule. The total number of base pairs is equal to the number of nucleotides in one of the strands (each nucleotide consists of a base pair, a deoxyribose sugar, and a phosphate group).
How do you identify a nitrogen base?
Pyrimidines are nitrogenous bases with 1 ring structure, whereas purines are nitrogenous bases with 2 ring structures. Cytosine and thymine are pyrimidines since they both have one ring structure, whereas adenine and guanine are purines with two connected ring structures.
What makes up the inner portion of DNA?
The interior portion of a DNA molecule is composed of a series of 4 nitrogenous bases: adenine (A), guanine (G), thymine (T), and cytosine (C). These bases are non-polar and therefore hyrdophobic (they don’t like water). Because the interior bases pair up in this manner, we say the DNA double helix is complimentary.
What are the four nitrogenous bases of DNA?
Attached to each sugar is one of four bases–adenine (A), cytosine (C), guanine (G), or thymine (T). The two strands are held together by hydrogen bonds between the bases, with adenine forming a base pair with thymine, and cytosine forming a base pair with guanine.
What does DNA contain the instructions for?
DNA contains the instructions needed for an organism to develop, survive and reproduce. To carry out these functions, DNA sequences must be converted into messages that can be used to produce proteins, which are the complex molecules that do most of the work in our bodies.
What are the four bases found in DNA?
Adenine, thymine, cytosine and guanine are the four nucleotides found in DNA.
What is not a base in DNA?
So uracil is not used in DNA. The four bases of DNA are: adenine (A), thymine (T), guanine (G), and cytosine (C).
What are the 8 bases of DNA?
Life as we know it uses 4 bases called A, C, T, and G. Recently, scientists expanded this alphabet to include 8 bases – 4 natural and 4 artificial. They dubbed the new code hachimoji DNA (‘hachi’ for eight, and ‘moji’ for letter).
How many different bases are there?
Summary: For decades, scientists have known that DNA consists of four basic units — adenine, guanine, thymine and cytosine. Those four bases have been taught in science textbooks and have formed the basis of the growing knowledge regarding how genes code for life.
What is base 7 called?
Septenary
What is base 8 called?
The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Octal numerals can be made from binary numerals by grouping consecutive binary digits into groups of three (starting from the right). For example, the binary representation for decimal 74 is 1001010.
What is base 4 called?
A quaternary /kwəˈtɜːrnəri/ numeral system is base-4. It uses the digits 0, 1, 2 and 3 to represent any real number.
What is base 5 called?
Quinary /ˈkwaɪnəri/ (base-5 or pental) is a numeral system with five as the base. A possible origination of a quinary system is that there are five digits on either hand.
What is base 3 called?
A ternary /ˈtɜːrnəri/ numeral system (also called base 3) has three as its base. Analogous to a bit, a ternary digit is a trit (trinary digit).
Is DNA a base 4?
DNA is more 2-based rather than 4, since you can have only 2 types of base pairs (AT and GC). However they can sit in 2 ways, which adds to overall 4 combinations.