Cancer Notes Week 6 PDF

Cancer notes Introduction: The Biology of Cancer Module 1: Why do cells become cancerous? Module 2: How does cancer affect my body? Module 3: How is cancer treated? Book notes lesson 1 - cancer=diease cause...

Cancer notes Introduction: The Biology of Cancer Module 1: Why do cells become cancerous? Module 2: How does cancer affect my body? Module 3: How is cancer treated? Book notes lesson 1 - cancer=diease caused by the inability to control cell division - Males have ½ chance to have cancer - Women have ⅓ chances to have cancer - Cancer has decreased by 33% - This is a result of todays generation - Cancer begins when a cell disregards genetic programming, loses specialization, and divides uncontrollably. - As the number of cancer cells increases —---> physiological changes frequently interfere with the operation of a tissue or organ. Lesson 1 What is cancer? - Cancer is a disease caused by the inability of the body to control cell division. - Can be caused by genetic or environmental factors - Most cancers are named based on the type of cells or tissues in where they originate - Some common forms of cancer - Melanoma: Skin - Leukemia: white blood cells in bone marrow - Carcinoma: the lining of the internal organs or skin - Sarcoma: connective tissue, such as bone - Lymphoma: cells and tissues of the immune system - This is a misconception that cancer is primarily in older adults - 4th leading cause of death in young people - Males have ½ chance to have cancer - Women have ⅓ chance to have cancer Cancer can influence almost every organ system of the body. Some major functions of systems. - Nervous system - Cardiovascular system - Digestive system - Muscular system - Endocrine system - Respiratory system - Urinary system - Lymphatic system - Integumentary system Lesson 2 How does a cell normally work? - Prokaryotic cells - Single circular chromosome attached to the cell membrane - Eukaryotic cells - Contain free floating linear chromosomes within a nucleus - These are different types of cells - Cells have the ability to: - Acquire materials and energy - Respond to their environment - Reproduce - Maintain an integral environment - Adapt to their enviroment - Cells are either prokaryotic (bacteria) or eukaryotic (animal, plant, fungi) Eukaryotic cells have membrane-bound organelles - Information processing - Nucleus: containing genetic info - Ribosomes: genetic info used to manufacture proteins - Energy - Mitochondria: converts energy found in nutrients - Transport and processing of nutrients - Endoplasmic Reticulum (ER): - Synthesis of proteins (rough ER), lipids (smooth ER), Carbohydrates (smooth ER) - Lysosome - Digestion of incoming nutrients  - Golgi apparatus - Processing center of the cell - Isolation - Plasma membrane - Isolates cells from the external environment - Selectively allows for passage materials - Cell division - Centrioles - Assist in dividing genetic material - During cellular reproduction Cell are specialized - During development - Cells receive genetic info —> specialized - Meaning they have a specific purpose in the body - While cancerous cells ignore the genetic programming that makes them specialized - This causes them to lose their function Enzymes are protein catalysts for chem reactions - The shape of enzymes determines how they will interact with molecules - Have an active site where the substrate binds - Products are released after the reaction - Some cancer drugs work by binding to the active site - These drugs prevent the substrate from reacting with the enzyme Information is contained within the DNA - DNA(deoxyribonucleic acid)= nucleic acid that stores genetic info2 - Consists of units called nucleotides - Nucleotides contain - 5 carbon deoxyribose sugar (pentagon) - Phosphate group - Nitrogen-containing base - 4 nucleotide subunits make up DNA - Adenine (A) = Thymine (T) - Guanine (G) = Cytosine( c) - Order of the nitrogen bases in DNA that store genetic info - Sum of all genetic info = genome - Genes = units of genetic info that provide  instructions for making proteins - The section of DNA that codes something is the gene Using the information found in DNA - GENE EXPRESSION - Occurs in 2 stages - Transcription - Translation - Transcription - nucleus - RNA polymerase exposes the nucleotide bases to be transcribed - Copy of mRNA (messenger) is made - Uracil (U) is used instead of Thymine(T) - mRNA is edited and leaves the nucleus - Transcribing information - creates mRNA that can leave the nucleus - Translation - Cytoplasm - mRNA moves to the ribosome - tRNA reads codons (3 nucleotides) of mRNA - Each codon has a corresponding amino acid - Which is brought to the ribosome by tRNA and assembled - Polypeptide is released - Ribosome and mRNA may be used again. - Translate into a new amino acid Protein structure is important for function - 4 levels of protein structure - Primary: linear sequence of amino acid - Secondary: amino acids interact based on weak chem reactions - Tertiary: 3-D molecule, functional - Quaternary: multiple protein chains interact to form larger molecules with more complex functions Lesson 3 How do cells divide? - Cell cycle: organized series of events required for cell division - Interphase- majority of cells time, normal functions - G1 (growth) - Organelles double - S (synthesis) - DNA replication occurs as chromosomes replicate - G2 (growth) - cell prepares to divide - M Phase- the portion where cell division occurs - Mitosis - cytokinesis - Checkpoint function to - Regulate speed of the cell movement through cell cycle - Ensure the cell is ready - If the cell is not ready it will be put into the G0 phase to try to repair its DNA - If that does not work then the cell may undergo apoptosis - 3 checkpoint: M, G1, G2 The genome - Total DNA content of a given cell - Genome is a simple circular strand of DNA in prokaryotic - Genome is a more complex double helical structure that is eukaryotic - Eukaryotic has a unique number of chromosomes located in the nucleus - Humans have 46, fruit flies have 8, spinach has 12 - Matched chromosomes = diploid - Cells contain only one set of chromosomes = haploid - Homologous chromosomes = matched chromosome pairs of diploid organism - One from Mom and one from Dad - At particular nucleotide segments, we find genes - There are 23 pairs of homologous chromosomes in  human somatic cells - These chromosomes are viewed within the nucleus - Removed from a cell in mitosis - Arranged according to length in an arrangement called karyotype DNA REPLICATION 1. Unwinding - The coiled - Double-stranded DNA molecule unwinds - Separates into 2-strand 2. Rebuilding - Enzymes connect a nucleotide with the appropriate base to the growing new strand - As the base bonds with the exposed - Complementary base 3. Each strand becomes a double - Each is identical to the cell's original double-stranded DNA molecule DNA REPLICATION 2 - Animal cell mitosis is divided into five stages - Prophase, prometaphase, metaphase, anaphase, and telophase - Mitosis is usually accompanied by cytokinesis Prophase - Chromosomes become visible - Spindle fibers emerge from the centrosome - The nuclear envelope breaks down - Centrosomes move toward opposite poles Prometaphase - Chromosomes continue to condense - Kinetoochoes appear at the centromeres - The mitotic spindle attaches to kinetochores Metaphase - Chromosomes line up - Each sister chromatid is attached to spindle fiber originating from opposite poles Anaphase - Centromeres split in 2 - Sister chromatids are pulled toward opposite poles  - Certain spindles begin to elongate the cell Telophase - Chromosomes arrive at opposite poles and begin to decondense - Nuclear envelope material surrounds each set of chromosomes - Spindle breaks down - Spindle fibers continue to push poles apart Cytokinesis - Animal cells: a cleavage furrow separates the daughter cells - Plant cells: a cell plate, the precursor to the new cell wall, separates the daughter cells Summary of mitosis 1. The condensing of chromosomes 2. All of the duplicated and condensed pairs of chromones move to the center of the cell 3. Each chromosome is pulled apart from its duplicate 4. New cell membranes form around each complete set of chromosomes and cytoplasm duplicates as well Lesson 4: Why do Cells stop dividing correctly? Tumor-Suppressor genes - Prevents unregulated cell growth - by slowing down the progression of cells through cell cycle - Most code for proteins that survey DNA for damage during G1 - Examples associated with breast cancer include p53 and BRCA1 Proto-Oncogenes - Speed up the cell cycle - Associated with signaling pathways: - Growth hormones intercat with target cell receptors - Proto-oncogenes are activated - Cell division is promotes - Become oncogenes when mutations cause them to  be “stuck” on - Only a single mutation is required for this - Examples : ERBB2