Cancer, DNA, RNA, Transcription & Translation

• Cancer is a cellular disease caused by the body's inability to control cell division.
• A tumor is a lump of cancer cells.
• Benign tumors do not break off and spread.
• Malignant tumors break off and spread.
• Metastasis is the spread of cancer to other parts of the body.
• DNA consists of two strands bound by a double-helix and is made up of nucleotides.
• Semi-conservative replication involves two strands of DNA unwinding and acting as a template for the new strand.
• RNA is single-stranded, comprised of ribose sugar, phosphate, and a nitrogenous base.
• DNA is double-stranded and contains the instructions for the cell to make proteins.

Transcription and Translation

• Transcription uses DNA information to make RNA and reads one strand of DNA to create a strand of messenger RNA, which is then edited and leaves the nucleus.
• Translation involves RNA moving out of the nucleus to ribosomes to form a protein.
• The messenger RNA is used to make the protein.

Types of Cancer by Location

• Melanoma affects the skin.
• Leukemia affects white blood cells in the bone marrow.
• Carcinoma affects the lining of the internal organs or skin.
• Sarcoma affects connective tissue, such as bone.
• Lymphoma affects cells and tissues of the immune system.

Body Systems

• The nervous system regulates and coordinates the activities of all other systems by responding quickly to internal and external stimuli.
• The endocrine system regulates and coordinates the activities of other systems more slowly than the nervous system by secreting hormones.
• The respiratory system supplies blood with oxygen for tissue cells, removes carbon dioxide, and helps regulate the acid-base balance.
• The cardiovascular system transports oxygen, nutrients, and wastes to/from tissue cells and transports hormones secreted by the endocrine glands.
• The digestive system supplies blood with nutrients and water for tissue cells and rids the body of indigestible remains.
• The urinary system excretes nitrogenous and other wastes and regulates water-salt and acid-base balance.
• The lymphatic system maintains blood volume by collecting excess interstitial fluid and returning it to the cardiovascular veins and defends against disease.
• The muscular system produces heat, maintains body temperature, protects and supports internal organs, and enables movement.
• The integumentary system helps maintain body temperature and protects internal organs.

Cell Growth Cycle

• G1 phase involves cells undergoing a major portion of growth.
• S phase involves DNA replication, producing chromosomes with two sister chromatids.
• G2 phase involves chromosomes coiling more tightly, preparing for mitosis, and forming a mitotic spindle.
• Cell centrioles grow out spindle fibers (mitotic spindle) that attach to each sister chromatid.
• Mitosis consists of mitosis (eukaryotic nuclear division) and cytokinesis (cell division),

Mitosis (PMAT)

• Prophase: Chromosomes condense and become visible, the nucleus breaks down, and the mitotic spindle forms and attaches fibers to each chromatid.
• Metaphase: Mitotic spindle fibers move chromosomes and line up in the middle of the cell.
• Anaphase: Each chromosome's copies (chromatids) are pulled to opposite sides of the cell by mitotic spindle fibers.
• Telophase: Chromatids are on opposite sides of the cell, the mitotic spindle breaks down, the nucleus reforms, chromosomes decondense, and the cell divides.
• Checkpoints regulate the speed at which the cell moves through the cell cycle, ensuring it is ready for division.
• Tumor-suppressor genes prevent unregulated cell growth by slowing down the progression of the cell through the cell cycle.
• Mutations can be caused by chemicals, radiation, or viruses.
• Mutations are any changes to the nucleotide sequence of DNA.
• Proto-oncogenes speed up the cell cycle, but mutations can cause them to become oncogenes, which are stuck "on" in normal cells.
• Oncogenes trigger cancer.

Cancer Stages

• Stage 1 is limited to a very small area and has not spread.
• Stage 2 is invasive, involves more than one tissue, but remains localized, and the lymph may be involved.
• Stage 3 is in the lymph nodes but has not spread to distant organs.
• Stage 4 means the cancer has fully metastasized.

Cancer Tests and Treatments

• Complete blood tests look at the presence of normal blood cells and basic blood chemistry.
• Polymerase chain reaction is a machine way to make copies and determine genes of interest.
• DNA sequencing identifies mutations that increase cancer risk.
• CT scans provides a 3D x-ray of the internal tissues.
• PET scans use radioactive tracers to measure cell metabolism, highlighting active cancer cells.
• MRI uses radio waves and magnets to detail images of soft tissue.
• Mammograms are x-rays.
• Chemotherapy uses chemicals to treat diseases by targeting the cell cycle of the fastest-growing cancer cells.
• Radiation uses high-energy gamma rays and x-rays, with shorter wavelengths delivering more energy.
• External radiation uses x-rays or gamma rays to target a specific cancer area.
• Internal radiation involves placing high doses of radioactive material in the body.
• Immunotherapy convinces the body's immune system to identify and eliminate cancer cells as "nonself."
• Cancers can occur when immune cells do not recognize cancer cells as nonself do not destroy them.