DNA (or deoxyribonucleic acid) is the molecule that carries the genetic information in all cellular forms of life and some viruses. It belongs to a class of molecules called the nucleic acids, which are polynucleotides – that is, long chains of nucleotides.

A genome is an organism’s complete set of genetic instructions. The instructions in our genome are made up of DNA. Within DNA is a unique chemical code that guides our growth, development and health.

Mutations that happen during Transcription and Translation. What happens if there is a mistake (mutation) in the DNA code? Possibly proteins won’t be made or are made improperly. If the mutations occur in the gametes, the offspring’s DNA will be affected positively, negatively, or neutrally.

Errors during translation elongation that result in incorporation of an incorrect amino acid, frameshifting (see Glossary), readthrough of stop codons, or premature termination can produce proteins that deviate from the encoded amino acid sequence.

But cells contain many different proteins whose job is to repair damaged DNA. But if the DNA damage occurs to a gene that makes a DNA repair protein, a cell has less ability to repair itself. So errors will build up in other genes over time and allow a cancer to form.

DNA damage occurs continuously as a result of various factors—intracellular metabolism, replication, and exposure to genotoxic agents, such as ionizing radiation and chemotherapy.

Most of the mistakes during DNA replication are promptly corrected by DNA polymerase which proofreads the base that has just been added. The polymerase checks whether the newly-added base has paired correctly with the base in the template strand. If it is the correct base, the next nucleotide is added.

DNA damaging agents are widely used in oncology to treat both hematological and solid cancers. Some commonly used modalities include ionizing radiation, platinum drugs (cisplatin, oxaliplatin, and carboplatin), cyclophosphamide, chlorambucil, and temozolomide.

DNA damage can be subdivided into two types: (1) endogenous damage caused by reactive oxygen species (ROS) that are derived from metabolic byproducts and (2) exogenous damage caused by radiation (UV, X-ray, gamma), hydrolysis, plant toxins, and viruses.

Endogenous sources of DNA damage include hydrolysis, oxidation, alkylation, and mismatch of DNA bases; sources for exogenous DNA damage include ionizing radiation (IR), ultraviolet (UV) radiation, and various chemicals agents.

Antimetabolites are called a “cytotoxic” type of drug because they kill cells. They work by mimicking the molecules that a cell needs to grow. Cells are tricked into taking in the drugs and then using the antimetabolites instead of their normal building blocks of genetic material: RNA and DNA.

Listen to pronunciation. (TAK-sayn) A type of drug that blocks cell growth by stopping mitosis (cell division). Taxanes interfere with microtubules (cellular structures that help move chromosomes during mitosis).

Cytotoxic drugs (sometimes known as antineoplastics) describe a group of medicines that contain chemicals which are toxic to cells, preventing their replication or growth, and so are used to treat cancer. They can also be used to treat a number of other disorders such as rheumatoid arthritis and multiple sclerosis.

Methotrexate is a chemotherapy drug used to treat many different cancers. It is best to read this information with our general information about chemotherapy and the type of cancer you have. Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

Many patients with rheumatoid arthritis have stayed on this drug for 20 years or more.

No interactions were found between methotrexate and Vitamin D3.

Even touching or inhaling the dust from the tablet can allow the medicine to get into the body. Methotrexate goes into sperm, so it’s important that a man taking it doesn’t get his partner pregnant.

Deoxyribonucleic acid (DNA) is a molecule you may already be familiar with; it contains our genetic code, the blueprint of life. This essential molecule is the foundation for the “central dogma of biology”, or the sequence of events necessary for life to function.

nucleus

Genes carry biological information that must be copied accurately for transmission to the next generation each time a cell divides to form two daughter cells.

In modern molecular biology labs, purified DNA polymerase is used routinely – to copy DNA by PCR (the polymerase chain reaction), for various recombinant DNA techniques, and to run sequencing reactions.

• It must be stable.
• It must be capable of being expressed when needed.
• It must be capable of accurate replication.
• It must be transmitted from parent to progeny without change.

Molecular genetics emerged from the realization that DNA and RNA constitute the genetic material of all living organisms. (1) DNA, located in the cell nucleus, is made up of nucleotides that contain the bases adenine (A), thymine (T), guanine (G), and cytosine (C). The RNA molecules in cells have two main roles.

DNA. DNA (deoxyribonucleic acid) forms the genetic material for almost all organisms on the planet (with the exception of some viruses that replace DNA with RNA or ribonucleic acid as the genetic material) (Lewin, 1999).

The Hershey–Chase experiments were a series of experiments conducted in 1952 by Alfred Hershey and Martha Chase that helped to confirm that DNA is genetic material.

DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA.

The Human Genome Is Composed of 24 Different Types of DNA Molecules. Human DNA is packaged into physically separate units called chromosomes. Humans are diploid organisms, containing two sets of genetic information, one set inherited from the mother and one from the father.

The first early hominid from Africa, the Taung child, as it was known, was a juvenile member of Australopithecus africanus, a species that lived one million to two million years ago, though at the time skeptical scientists said the chimpanzee-size braincase was too small for a hominid.

There has been inbreeding ever since modern humans burst onto the scene about 200,000 years ago. Now having said this, there is no sharp cutoff between inbreeding and not inbreeding. Since we are all humans and all share a common ancestor somewhere down the line, we all have some degree of inbreeding.

L0 is especially important in that regard, as all living people are believed to descend on their maternal line from the woman who first carried the sequence, a hypothetical woman called “mitochondrial Eve.” Today, the L0 lineage is found most commonly in the Khoisan people, two indigenous groups living in southern …

Now, a team of researchers, led by Cosimo Posth from the University of Tübingen in Germany, analysed the DNA of an ancient skull belonging to a female individual called Zlatý kůň and found that she lived around 47,000 – 43,000 years ago – possibly the oldest genome identified to date.

According to calculations by geneticist Graham Coop of the University of California, Davis, you carry genes from fewer than half of your forebears from 11 generations back. Still, all the genes present in today’s human population can be traced to the people alive at the genetic isopoint.

Confucius