The Structure of DNA and Cancer
DNA replication
DNA replication begins when the two sides of the molecule unwind and separate between the base pairs like a zipper. Free nitrogen bases in the nucleus then pair up with the bases on the sides of the molecule according to the rule: A always with T, and C always with G.
How are DNA, genes, and chromosomes related?
DNA, genes, and chromosomes are all related because chromosomes are condensed rods of chromatin which contains DNA that carries genetic information. They are all important features of a cell as a result of all carrying needed materials to new cells.
Doctors treat cancer
Doctors usually treat cancer through three treatments; through surgery, through radiation, which are beams of high-energy waves which destroy the cancer, or through chemotherapy, which are drugs that kill cancer.
What happened in 1953?
In 1953, American scientist James Watson and British scientist Francis Crick became the first to figure out the structure of the DNA molecule. This discovery revealed important information on how DNA copies itself.
Chromosome
Made up of a DNA molecule and proteins. A gene is a section of the DNA molecule, a sequence of nitrogen base pairs.
Can base A form a rung with base C? Explain why or why not.
No, Base A cannot form a rung with base C. The rule states A always goes with T and C always goes with G. This would violate the rules and genetic code resulting in a mutation within the organism.
Two things that can cause cancer
One thing that can cause cancer is the use of tobacco. When people repeatedly smoke, tobacco and carcinogens are exposed to the body, causing cells to become damaged. Another way cancer can begin is through an unhealthy diet and frequently consuming high-fat foods. People should eat lots of fruit, vegetables and grain products to prevent cancer.
Mutations
Sometimes a mistake can occur in the DNA replication process resulting in a change in the base sequence. A mutation is a change in a gene or chromosome. Changes to organisms brought about by mutation can be harmful, helpful, or neither harmful nor helpful to the organism.
DNA structure
The DNA molecule is shaped like a twisted ladder or double helix. The sides are made up of alternating molecules of deoxyribose (a sugar) and phosphates. Each rung is made up of a pair of molecules called nitrogen base; called a base pair. DNA has four different nitrogen bases: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). On a rung, A only pairs with T, and C only pairs with G.
The Genetic Code
The order of the nitrogen bases (A, T, C, and G) along a gene forms the genetic code. Differences in the sequence are the genetic differences between the organisms. A difference in just a few base pairs could be the difference between brown vs. blue eyes, for example.
Why is the DNA molecule often called a "double helix"?
A DNA molecule is often called a "double helix" due to the fact that its shape resembles a twisted ladder, or spiral staircase. Also, a helix is a shape that twists like threads of a screw, similar to the structure of DNA.
Growth and spread of cancer
A mutation occurs in a cell, causing a change in the DNA. A tumor, or mass of cells that divide uncontrollably, forms. Cancer spreads to other parts of the body when cancer cells enter the bloodstream.
How can cancer begin?
Cancer can begin by a change in DNA affecting the cell cycle, and a cell divides too often.
Cancer
Cancer is a disease in which some body cells grow and divide uncontrollably, damaging the parts of the body around them.
