A class of nitrogenous compounds containing one heterocyclic ring. Two pyrimidines, cytosine and thymine, commonly are found in DNA; in RNA, uracil replaces thymine. (Figure 4-2) ...
important organic compounds (bases) such as cytosine, thymine, and uracil, which are constituents of nucleic acids
Source: Noland, George B. 1983. General Biology, 11th Edition. St. Louis, MO. C. V. Mosby ...
Pyrimidine is a heterocyclic aromatic organic compound, which is similar to benzene and pyridine and that contains two nitrogen atoms at positions 1 and 3 of the six-membered ring.
s are nitrogen containing organic bases. They are some of the building blocks of DNA and RNA.
View Dr Chromo's lecture on 'DNA'.
Pyrimidine: A nitrogen containing, single ring compound that occurs in nucleic acids. In DNA molecules, the pyrimidines are cytosine and thymine.
Radioactive phosphorus (32P): radioactive isotope of 31P, an element found in DNA molecules.
Covalent bonds formed between two adjacent s on the same strand of DNA induced by Ultraviolet irradiation.
pyrimidine One of the groups of nitrogenous bases that are part of a nucleotide. Pyrimidines are single ringed, and consist of the bases thymine (in DNA), uracil (replacing thymine in RNA), and cytosine. PICTURE ...
A nitrogenous base, such as cytosine, thymine, or uracil, with a characteristic single-ring structure; one of the components of nucleic acids.
pyrimidine a type of nitrogenous base in DNA molecules that has one ring containing carbon and nitrogen atoms; two examples in DNA are cytosine (C) and thymine (T).
recessive the allele overshadowed by the dominant allele.
/pə-RIM-ə-deen/ One of the two types of nitrogenous bases occurring in nucleic acids. s are composed of a six-member heterocyclic ring of carbon and nitrogen atoms. The s occurring in DNA are cytosine and thymine.
Pyrimidine - One of two categories of nitrogen base ring compounds found in DNA and RNA. A six-membered ring containing two nitrogens. See purine.
A nitrogen-containing, single-ring, basic compound that occurs in nucleic acids. The s in DNA are cytosine and thymine; in RNA, cytosine and uracil.
See also: base pair
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 Pyrimidine ribonucleotides
The synthesis of UMP.
The color scheme is as follows: enzymes, coenzymes, substrate names, inorganic molecules ...
s (single ring of C and N - smaller)
Thymine or Cytosine
Base pairing by weak hydrogen bonds ...
Pyrimidines have a single six-membered ring.
There are three different pyrimidines: cytosine (C), thymine (T), and uracil (U).
Purines have a six-membered ring joined to a five-membered ring.
An organic base composed of a single ring of carbon and nitrogen atoms; parent substance of several bases found in nucleic acids.
pyrogenic Substance that causes a rise in body temperature; causes fever.
Uracil a pyrimidine nitrogenous base that is found in RNA
Urea the main nitrogenous waste product of mammals
Urine an aqueous solution produced by the kidneys in mammals, that contains urea, inorganic salts and water.
Uracil is a base (nitrogenous base) and constituent of nucleotides and as such one member of the base pair A-U (adenine-uracil). It is normally found in RNA but not DNA.
purines and pyrimidines
polyols — compounds with hydroxyl groups on a backbone of 3 to 6 carbons such as glycerol and glyceric acid. Sugars are polyols.
the amino acids listed here.
uracil The that replaces thymine in RNA molecules and nucleotides.
ureter A muscular tube that transports urine by peristaltic contractions from the kidney to the bladder. PICTURE ...
A nitrogen-containing, single-ring, basic compound (cf. nitrogenous base) that occurs in nucleic acids. The pyrimidines in DNA are cytosine and thymine. The pyrimidines in RNA are cytosine and uracil.
The purines in DNA and RNA are adenine and guanine.
A nitrogen-containing, double-ring, basic compound that occurs in nucleic acids. The s in DNA are cytosine and thymine; in RNA, cytosine and uracil.
Thymine, Uracil and Cytosine all have a single ring structure and are classified as Pyrimidines.
Their molecules look like this:
When the base pairs form, a consistent spacing is obtained between the polynucleotide chains.
Both purines and s are flat in the ring plane. The upper and lower surfaces of the rings are hydrophobic, while the edges are hydrophilic.
The purines (adenine and guanine) and pyrimidines (thymine, cytosine, and uracil) that comprise DNA and RNA molecules. Nodule. The enlargement or swelling on roots of nitrogen- fixing plants. The nodules contain symbiotic nitrogen- fixing bacteria.
base pair a pair of hydrogen-bonded nitrogenous bases (one purine and one ) that join the component strands of the DNA double helix.
In twofold degenerate sites, the equivalent nucleotides are always either two purines (A/G) or two pyrimidines (C/U), so only transversional substitutions (purine to pyrimidine or pyrimidine to purine) in twofold degenerate sites are nonsynonymous.
Transitions (changes from a purine - A or G - to the other purine, or a - C or T - to the other ) are more likely than transversions (changes from a purine to a or vice-versa).
Two nitrogenous (purine or pyrimidine) bases (adenine and thymine or guanine and cytosine) held together by weak hydrogen bonds. Two strands of DNA are held together in the shape of a double helix by the bonds between base pairs.
The other difference that you'll see in the structure of the nucleotides is that it uses the same guanine and adenine and cytosine that DNA uses but instead of using thymine uses a particular kind of called uracil.
Thymine and Cytosine are pyrimidines as they only have one ring in their molecular structure. A purine will link with a pyrimidine.
- A base-pair substitution mutation resulting in the replacement of one purine by another purine or of one by another
- The process of biosynthesis of a polypeptide chain using genetic instructions from the mRNA ...
Glycosylated base is cytidine, it's derived from pyrimidine. It is one of the four nitrogenous bases, including in dna adenine, thymine, and guanine, and in rna adenine, uracil, and guanine.
See also: DNA, Nucleotide, Base, Molecule, Purine