Genetics & Molecular Biology

Chromosomes are molecules of DNA and proteins. They are located in the nucleus of the cell and their function is to carry genes.

DNA consists of 3 basic components: 1) a phosphate group, 2) a five-carbon sugar, 3) a cyclic nitrogen-containing compound called a base.

DNA replication is a process in which the DNA molecule duplicates producing two molecules of DNA from the original one DNA molecule.

Transcription is the first step of gene expression - the process in which the information in the gene is used to synthesize a product (a protein).

Translation, the process of synthesizing a protein from the transcribed RNA (mRNA), is the second step of gene expression.

Genetic code is the language, set of rules or instructions that the organism uses to translate information in a gene into a protein.

The central dogma of molecular biology is a theory that explains the flow of genetic information in an organism.

What are you going to learn? * What is the difference between RNA and DNA? * What are the different types of RNA molecules? * What is the function of mRNA, tRNA, and rRNA? * terms: pre-mRNA, snRNAs, snRNPs, anticodon Like DNA, RNA (ribonucleic acid) also consists of 3 basic components:1) a ph…

A mutation is a change in the genetic information in an organism. For example, when a sequence of CGA gets changed into AGA, we talk about a mutation.

The Ames test is used to evaluate whether a certain subtance could be a possible carcinogen - a substance capable of causing cancer.

Sickle cell anemia is a perfect example of how dangerous a single base substitution can be.

Fragile X syndrome is a very common form of inherited mental retardation. The X chromosome contains a fragile site that contains a trinucleotide repeat CGG.

The organism has dfferent mechanisms that it can use repair DNA damage. In this article, we will talk about the mismatch repair, base excision repair, nucleotide excision repair, double-strand break repair, nonhomologous end joining, and homologous recombination.

Xeroderma pigmentosum is a disease that illustrates what happens when DNA repair does not work properly. The disease is characterized by abnormal skin pigmentation that resembles freckles and sensitivity to sunlight.

Restriction enzymes are enzymes produced by bacteria that recognize and cut specific nucleotide sequences in DNA, which we call recognition sequences or restriction sites.

Cloning vectors are DNA molecules with inserted DNA fragments. They are useful for copying fragments of DNA as they can be introduced into a host cell and replicate.

PCR or polymerase chain reaction a very powerful laboratory technique that is used for copying segments of DNA.

RT-PCR is a modification of standard PCR, which uses reverse transcriptase to transcribe RNA into cDNA, which is then amplified using the standard PCR.