Term | Definition |
DNA | deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information. |
Deoxyribose | the sugar, obtained from DNA by hydrolysis. |
Parts of a Nucleotide | The basic building block of nucleic acids, such as DNA and RNA. It is an organic compound made up of nitrogenous base, a sugar, and a phosphate group. |
Purine | the bases adenine and guanine, which are fundamental constituents of nucleic acids. Any of a group of organic compounds containing two fused rings of carbon and nitrogen atoms. |
Pyrimidine | Any of a group of organic compounds having a single six-member ring in which the first and third atoms are nitrogen and the rest are carbon. Pyrimidines include the bases cytosine, thymine, and uracil, which are components of DNA and RNA. |
Hydrogen bond | A chemical bond formed between an electropositive atom and a strongly electronegative atom, Hydrogen bonds are responsible for the bonding of water molecules in liquid and solid states, and are weaker than covalent and ionic bonds. |
Helicase | any of the enzymes that use the energy derived from the hydrolysis of nucleoside triphosphates to unwind the double-stranded helical structure of nucleic acids |
DNA Polymerase | Any of various enzymes that function in the replication and repair of DNA by catalyzing the linking of nucleotides in a specific order, using single-stranded DNA as a template. |
RNA | Short for ribonucleic acid. The nucleic acid that is used in key metabolic processes for all steps of protein synthesis in all living cells and carries the genetic information |
Ribose | a white, crystalline, water-soluble, slightly sweet solid, a pentose sugar obtained by the hydrolysis of RNA. |
mRNA | Messenger RNA is RNA that carries genetic information from the cell nucleus to the structures in the cytoplasm (known as ribosomes) where protein synthesis takes place. |
rRNA | Ribosomal RNA is the main structural component of the ribosome. |
tRNA | Transfer RNA is RNA that delivers the amino acids necessary for protein synthesis to the ribosomes. Compare DNA. |
Ribosome | A sphere-shaped structure within the cytoplasm of a cell that is composed of RNA and protein and is the site of protein synthesis. Ribosomes are free in the cytoplasm and often attached to the membrane of the endoplasmic reticulum. |
How is DNA different from RNA? | RNA consists of a single strand of nucleotides, and occurs in a variety of lengths and shapes. RNA also differs from DNA in having the pyrimidine base uracil instead of thymine and in having ribose instead of deoxyribose in its sugar-phosphate backbone |
Protein Synthesis | the process by which amino acids are linearly arranged into proteins through the involvement of ribosomal RNA, transfer RNA, messenger RNA, and various enzymes. |
Amino Acid | Any of a large number of compounds found in living cells that contain carbon, oxygen, hydrogen, and nitrogen, and join together to form proteins. |
Codon | a triplet of adjacent nucleotides in the messenger RNA chain that codes for a specific amino acid in the synthesis of a protein molecule. |
Anticodon | a sequence of three nucleotides in a region of transfer RNA that recognizes a complementary coding triplet of nucleotides in messenger RNA during translation by the ribosomes in protein biosynthesis. |
Transcription | the process by which genetic information on a strand of DNA is used to synthesize a strand of complementary RNA. |
Translation | The process in the ribosomes of a cell by which a strand of messenger RNA directs the assembly of a sequence of amino acids to make a protein. |
Polypeptide | a chain of amino acids linked together by peptide bonds and having a molecular weight of up to about 10,000. |
Promoter | a site on a DNA molecule at which RNA polymerase binds and initiates transcription, a gene sequence that activates transcription. |
Griffith | Griffith showed that genetic information could be transferred from dead bacterial cells to live ones via a process called transformation. |
Avery/McCarty/MacLeod | that DNA is the substance that causes bacterial transformation, in an era when it had been widely believed that it was proteins that served the function of carrying genetic information, which further supported Griffith's theory |
Hershey and Chase | 1969 Nobel Prize in Physiology or Medicine for his “discoveries concerning the genetic structure of viruses.” |
Rosalind Franklin | Rosalind Franklin's X-ray studies of molecules played a crucial role in the 1953 discovery of the structure of DNA. |
Watson and Crick | The two twentieth-century biologists (James D. Watson of the United States and Francis H. C. Crick of England ) who discovered the double helix of DNA. |
Chargaff | discovered that DNA is the primary constituent of the gene, thereby helping to create a new approach to the study of the biology of heredity. |