In this post, we will talk about biology questions: In the accompanying image, a nucleotide is indicated by the letter _____. We collected this post from the internet just for study.
You can find more related biology questions in the MCAT practice test (Biology part).
In the accompanying image, a nucleotide is indicated by the letter _____.
- The answer and explanations are below.
What is Nucleotide?
Nucleotides are a class of compounds consisting of three substances: purine bases or pyrimidine bases, ribose or deoxyribose, and phosphate, also known as nucleosides.
Pentose and organic bases synthesize nucleotides, nucleosides, and phosphate synthesize nucleotides, and four nucleotides make up nucleic acids. Nucleotides are mainly involved in the composition of nucleic acids, and many single nucleotides also have a variety of important biological functions, such as adenosine triphosphate (ATP) and dehydrocoenzyme, which are related to energy metabolism.
Classification of Nucleotides
Depending on the sugar, there are two types of nucleotides: ribonucleotides and deoxyribonucleotides.
Depending on the base, there are adenine nucleotides (AMP), guanine nucleotides (GMP), cytosine nucleotides (CMP), uracil nucleotides (UMP), thymine nucleotides (TMP), and hypoxanthine nucleotides (IMP).
The phosphate in nucleotides is available in one-, two- and three-molecule forms. In addition, nucleotide molecules can be dehydrated and condensed to form cyclic nucleotides.
Nucleotides are the basic units of ribonucleic acid and deoxyribonucleic acid, which are the precursors of nucleic acid synthesis in the body. Nucleotides are distributed in the nucleus and cytoplasm of organs, tissues, and cells in living organisms along with nucleic acids. As a component of nucleic acid, it is involved in basic life activities such as heredity, development, and growth of living organisms.
There are also considerable amounts of nucleotides in free form in living organisms. Adenosine triphosphate plays a major role in cellular energy metabolism. The release and absorption of energy in the body is mainly reflected by the production and consumption of adenosine triphosphate.
In addition, uridine triphosphate, cytidine triphosphate, and guanosine triphosphate are also sources of energy in the anabolism of some substances. Adenosine is also a component of some coenzymes, such as coenzyme I, coenzyme II and coenzyme A.
Functions of Nucleotides
Nucleotides have important biological functions and are involved in almost all biochemical reactions in living organisms. They are summarized in the following five aspects.
(1) Nucleotides are the precursors for the synthesis of biological macromolecules ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).
There are four main types of nucleotides in RNA: AMP, GMP, CMP, and UMP, and these four types of nucleotides are synthesized from scratch from simple substances such as ribose phosphate, amino acids, one-carbon units, and carbon dioxide.
There are four main types of deoxyribonucleotides in DNA: dAMP, dGMP, dCMP, and dTMP, which are reduced from their respective corresponding nuclear carbon nucleotides at the diphosphate level.
(2) Adenosine triphosphate (ATP) plays an extremely important role in cellular energy metabolism. A portion of the energy produced during the oxidation of substances is stored in the high-energy phosphate bonds of the ATP molecule.
(3) ATP can also transfer high-energy phosphate bonds to UDP, CDP, and GDP to produce UTP, CTP, and GTP, which are also direct sources of energy in some anabolisms. Moreover, in some synthetic reactions, some nucleotide derivatives are also activated intermediate metabolites.
(4) Adenosine is also an important coenzyme in the aerobic oxidation of sugar and fatty acid oxidation.
(5) Nucleotides have a regulatory role for many basic biological processes. They are the basic components of all living organisms and play a dominant role in growth, development, reproduction, and heredity.
Correct Answer
Below is the correct answer to In the accompanying image, a nucleotide is indicated by the letter _____.
- B
In the accompanying image, a nucleotide is indicated by the letter B.
You might interest in:
