Chapter 10

Nitrogenous Base

a nitrogen-containing organic compound that has the chemical properties of a base, especially a pyrimidine or purine

Ribose

a sugar of the pentose class that occurs widely in nature as a constituent of nucleosides and several vitamins and enzymes.

Ribosomal RNA (RRNA)

In molecular biology, ribosomal ribonucleic acid (rRNA) is the RNA component of the ribosome, and is essential for protein synthesis in all living organisms.

Complementary Base Pair

It describes the manner in which the nitrogenous bases of the DNA molecules align with each other. They are responsible for the DNA structure (double-helix)

Termination Signal

Stop of mRNA synthesis

Genome

the haploid set of chromosomes in a gamete or microorganism, or in each cell of a multicellular organism.

Genetic Code

the nucleotide triplets of DNA and RNA molecules that carry genetic information in living cells.

Codon

A codon is a sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis. DNA and RNA molecules are written in a language of four nucleotides; meanwhile, the language of proteins includes 20 amino acids.

Virulent

Actively poisonous; deadly

Nucleotide

Any of a group of molecules that, when linked together, form a building block of DNA or RNA: composed of a phosphate group, the bases adenine, cytosine, guanine, and thymine, and a pentose sugar, in RNA the thymine base being replaced by uracil

Deoxyribose

Any of certain carbohydrates derived from ribose by the replacement of a hydroxyl group with a hydrogen atom

Replication

DNA replication. The double helix is unwound and each strand acts as a template for the next strand. Bases are matched to synthesize the new partner strands. DNA replication is the process of producing two identical replicas from one original DNA molecule.

Anticodon

Each tRNA contains a specific anticodon triplet sequence that can base-pair to one or more codons for an amino acid. Some anticodons can pair with more than one codon due to a phenomenon known as wobble base pairing.

Messenger RNA (mRNA)

Messenger RNA (mRNA) is a large family of RNA molecules that convey genetic information from DNA to the ribosome, where they specify the amino acid sequence of the protein products of gene expression.

Ribonucleic Acid (RNA)

Ribonucleic acid, or RNA is one of the three major biological macromolecules that are essential for all known forms of life (along with DNA and proteins). A central tenant of molecular biology states that the flow of genetic information in a cell is from DNA through RNA to proteins: "DNA makes RNA makes protein.

Semi-conservative

Semiconservative replication would produce two copies that each contained one of the original strands and one new strand. Conservative replication would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs.

DNA polymerase

The DNA polymerases are enzymes that create DNA molecules by assembling nucleotides, the building blocks of DNA. These enzymes are essential to DNA replication and usually work in pairs to create two identical DNA strands from a single original DNA molecule.

Protein Synthesis

The creation of proteins by cells that uses DNA, RNA and various enzymes

Base Sequence

The order of nucleotide bases in a DNA molecule

Replication Fork

The point at which the two strands of DNA are separated to allow replication of each strand

DNA replication

The process whereby a copy of a DNA molecule is made and thus the genetic information it contains is duplicated. The parental double stranded dna molecule is replicated semi conservatively, i.e. Each copy contains one of the original strands paired with a newly synthesised strand that is complementary in terms of AT and GC base pairing. Though in this sense conceptually simple, mechanistically a complex process involving a number of enzymes.

Transcription

Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA by the enzyme RNA polymerase. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language.

Transfer RNA (tRNA)

Transfer RNAs (tRNAs) are small RNA molecules containing 75 to 95 nucleotides. Cells contain many different tRNA molecules. Most of the tRNAs function as carriers of amino acids and participate in protein synthesis.

Translation

Translation is the process of translating the sequence of a messenger RNA (mRNA) molecule to a sequence of amino acids during protein synthesis. The genetic code describes the relationship between the sequence of base pairs in a gene and the corresponding amino acid sequence that it encodes.

Helicase

a prokaryote enzyme that uses the hydrolysis of atp to unwind the dna helix at the replication fork, to allow the resulting single strands to be copied.

Promoter

a site on DNA to which the enzyme RNA polymerase can bind to initiate the transcription of DNA into RNA.

RNA Polymerase

an enzyme that is responsible for making rna from a dna template. In all cells RNAP is needed for constructing rna chains from a dna template, a process termed transcription. In scientific terms, RNAP is a nucleotidyl transferase that polymerizes ribonucleotides at the 3' end of an rna transcript. Rna polymerase enzymes are essential and are found in all organisms, cells, and many viruses.

Bacteriophage

any of a group of viruses that infect specific bacteria, usually causing their disintegration or dissolution

Transformation

change in form, appearance, nature, or character; the state of being transformed

Mutation

changing the structure of the gene

Base-pairing rules

constraints imposed by the molecular structure of DNA and RNA on the formation of hydrogen bonds among the four purine and pyrimidine bases such as that adenine pairs with thymine or uracil, and guanine pairs with cytosine

Purine

one of several purine derivatives, especially the bases adenine and guanine, which are fundamental constituents of nucleic acids

Pyrimidine

one of several pyrimidine derivatives, especially the bases cytosine, thymine, and uracil, which are fundamental constituents of nucleic acids