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Old Friday, October 22, 2010
Sadia Munawar Sadia Munawar is offline
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Default Explaining some difficult terms

Quote:
Originally Posted by mitariq View Post
In virus, either DNA or RNA, never both present.
Quote:
Originally Posted by Mao Zedong View Post
DNA and RNA are two molecules that are found in the cells of every organism. DNA stands for Deoxyribonucleic acid while RNA is short for Ribonucleic acid. Both have specific functions related to the growth and replication of the organism through cell division and protein synthesis. However, DNA and RNA have differences in both structure and use.

The main difference between DNA and RNA molecules is the type of sugar that is present in them. DNA is composed of deoxyribose sugar while RNA is made up of ribose sugar. The main difference between the two sugars is that deoxyribose has more OH.

Another difference between DNA and RNA is their predominant structure. DNA is a double-stranded molecule with a long chain of nucleotides while RNA is a single-stranded molecule having shorter chains of nucleotides. Both DNA and RNA are polymers however; each molecule has its own set of bases. The difference in DNA and RNA bases is that RNA has the base uracil, and DNA has a base of thymine.

The difference in roles each of these molecules has in cell biology is: DNA serves as the storage of genetic information of an organism, while RNA acts as a messenger that relays the genetic information from the nucleus to the ribosome.

MOLECULE = The smallest particle of a substance that retains the chemical and physical properties of the substance and is composed of two or more atoms; a group of like or different atoms held together by chemical forces. A molecule is formed when 2 or more atoms join together chemically.

REPLICATION = division in a such a way that an exact copy of the original is made

POLYMER = a long-chained (or large / macro) molecule that is made up of repeating smaller units, called "monomers". Examples of polymers: proteins, DNA, RNA, Plastics, etc.

PROTEIN SYNTHESIS = the creation or production of proteins in biological cells using DNA or RNA.

NUCLEOTIDE = one of the chemical building blocks of DNA or RNA (cf. nuclide) A nucleotide consists of a nitrogenous base (adenine, guanine, thymine, or cytosine in DNA; adenine, guanine, uracil, or cytosine in RNA), a sugar molecule (deoxyribose in DNA; ribose in RNA), and a phosphate group.
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