Exam 4 Cancer Study Guide PDF

**[Exam 4 Cancer]** Intro Bio -- exam 4 study guide **[Study Guide -- Chapter 9 and Cancer]**\ Define all terms in all PowerPoints\ **[Define gene]** - **[Hereditary Information]** - The functional and physical unit of heredity passed from parent to offspring. - essentially acting as...

**[Exam 4 Cancer]** Intro Bio -- exam 4 study guide **[Study Guide -- Chapter 9 and Cancer]**\ Define all terms in all PowerPoints\ **[Define gene]** - **[Hereditary Information]** - The functional and physical unit of heredity passed from parent to offspring. - essentially acting as the **[\"instruction manual\"]** for building proteins within a cell. **[Structure of DNA tells us what?]** - The structure of DNA tells us the genetic information of an organism **[What are Chargaff's rules?]** - Chargaff\'s **[First Rule]** underscores complementary **[base pairing:]** A pairs with T, and C pairs with G - Chargaff\'s **[Second Rule]** reveals consistent ratios of A to T and C to G in DNA strands. - Chargaff\'s rules state that DNA from any cell of all organisms should have a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases. **[If given a DNA sequence, use Chargaff's rules to explain the complementary sequence.]** - to find the complementary sequence of a DNA strand, simply replace each A with a T, each T with an A, each C with a G, and each G with a C; essentially, \"flipping\" the base pairs on the opposite strand. - Example: - Original DNA sequence: ATCGTAC - Complementary sequence: TAGCATG **[Griffith's experiment ]** - Injected mice with different combinations of live and heat-killed Streptococcus pneumoniae bacteria, discovering that a \"transforming principle\" from the killed virulent strain could transform a non-virulent strain into a deadly one **[Avery's experiment:]** - Following up on Griffith\'s findings, Avery and his colleagues isolated and purified the **[\"transforming principle\"]** from the killed bacteria, proving that it was DNA, not protein or other cellular components, responsible for the transformation. **[What did Griffith's and Avery's experiments tell us?]** - Griffith\'s and Avery\'s experiments together provided strong evidence that **[DNA is the genetic material.]** **[What are bacteriophages?]** - A bacteriophage is a type of virus that infects bacteria and moves DNA from one bacterium to another. - A bacteriophage is a type of **[virus that infects and replicates within bacteria.]** - **[\"bacteria eater,\"]** **[What did the Hersey-Chase experiments tell us?]** - **[DNA is the hereditary material.]** - **[DNA is the genetic material responsible for the inheritance of traits. ]** - The Hershey-Chase experiments definitively established that **[DNA, not protein, is the genetic material responsible for inheritance of traits,]** - proving that when a virus infects a bacteria, it is the viral DNA that enters the bacteria and serves as the genetic blueprint, while the protein coat remains outside the cell. **[What is the structure of DNA?]** - has a structure called a double helix, which means it consists of two strands that twist around each other like a spiral staircase, with the \"rungs\" of the ladder formed by pairs of nitrogenous bases (adenine, thymine, cytosine, and guanine) - the sides of the ladder made up of alternating sugar (deoxyribose) and phosphate groups; each strand is held together by complementary base pairing. -. In its natural state, each DNA molecule is actually **[composed of two single strands held together along their length with hydrogen bonds between the bases.]** **[What is semi-conservative replication of DNA?]** - each new DNA molecule formed during replication contains one strand from the original parent DNA molecule and one newly synthesized strand, essentially **[\"conserving\"]** half of the original DNA in each new copy; **[What enzymes are involved in DNA replication and what do they do?]** - **[DNA helicase]** - (unzips the DNA double helix), - **[DNA polymerase]** - (synthesizes new DNA strands by adding nucleotides), - **[DNA primase]** - (creates RNA primers to initiate replication), - **[DNA ligase]** - (joins DNA fragments together), and - **[single-strand binding proteins]** - (stabilize separated DNA strands) **[Leading strand ]** - needs 1 primer **[What are Okazaki fragments?]** - **[the DNA fragments that are synthesized in short stretches on the lagging strand]** - **[Lagging strand replicates in short segments.\ ]** How are DNA mistakes repaired? - **[Proofreading]** - The primary mechanism for correcting errors during DNA replication, where DNA polymerase identifies and replaces incorrect bases as it adds them **[What is the Central Dogma of biology?]** - The central dogma describes **[the flow of genetic information in the cell from genes to mRNA to proteins.]** Define transcription and translation. Where do they occur and how do they work? - **[Transcription]** is the process where a gene\'s DNA sequence is copied into a messenger RNA (mRNA) molecule, occurring in the nucleus of eukaryotic cells - **[\"transcribes\" the genetic code from DNA to RNA]** - **[Translation]** is the process where the information in mRNA is used to build a protein chain of amino acids, taking place on ribosomes in the cytoplasm - **[\"translates\" that RNA code into a protein. ]** **[What are the 3 phases of translation? What happens during each?]** - **[Initiation]** - The small ribosomal subunit binds to the start of the mRNA sequence, and the start codon AUG signals the beginning of translation. - **[Elongation]** - The ribosome moves along the mRNA, reading codons and adding amino acids to form a polypeptide chain. - **[Termination]** - A stop codon (UAA, UAG, or UGA) enters the ribosome, the polypeptide is released, and the final amino acid detaches from the tRNA. **[What are the 3 types of RNA and what are they used for?]** - **[messenger RNA (mRNA),]** which carries the genetic code for protein synthesis, - **[transfer RNA (tRNA),]** which brings amino acids to the ribosome during translation, and - **[ribosomal RNA (rRNA),]** which forms the structural core of the ribosome where protein synthesis occurs **[What is a promoter?]** - a \"promoter\" is a specific DNA sequence **located upstream of a gene where RNA polymerase binds to initiate the process of transcription** What does RNA polymerase do? - RNA polymerase is **[an enzyme that copies DNA into RNA, a process called transcription]** **[What are triplets/codons? Why do we have codons?]** - Triplet codons are sequences of three nucleotides in DNA or RNA that specify a particular amino acid or signal the start or stop of protein synthesis - **[Why do we have codons?]** - The purpose of codons is to translate the language of DNA and RNA nucleotides into the language of amino acids, which are the building blocks of proteins **[What are introns and exons?]** - **[\"introns\"]** are **[non-coding sections of DNA]** within a gene that are removed during RNA splicing - introns are the \"intervening\" sequences that are cut out, leaving only the expressed exons to code for a protein - **[\"exons\"]** are **[the coding sections of DNA]** that are joined together to form the final messenger RNA (mRNA) which is used to produce proteins **[What is the function of ribosomes?]** - The function of ribosomes is **[to carry out protein synthesis within a cell]** - Process - Ribosomes \"read\" the mRNA sequence, matching each codon (set of three nucleotides) to the corresponding amino acid brought by a transfer RNA (tRNA) molecule, and then linking these amino acids together to build a protein chain **[What are the differences between DNA and RNA?]** - DNA is double-stranded, forming a double helix, while RNA is typically single-stranded - DNA contains the sugar deoxyribose, whereas RNA contains ribose - DNA uses the base thymine while RNA uses uracil instead of thymine **[How are genes turned on and off?]** - **[Gene regulation]** - where specific proteins called transcription factors bind to DNA regions near a gene, essentially acting as switches to either allow or prevent the gene from being transcribed into RNA, which is then translated into protein **[Define wild type]** - wild type is the most common gene, characteristic, or phenotype in a natural population **[What are insertions and deletions?]** - insertions and deletions are types of mutations that occur when DNA is changed by adding or removing nucleotides - **[Insertion:]** A mutation where extra base pairs are added to a DNA sequence - **[Deletion:]** A mutation where a section of DNA is removed, which can be as small as a single base or as large as an entire gene **[What are mutagens?]** - a \"mutagen\" is **[any chemical or physical agent that can cause permanent changes in an organism\'s DNA, leading to mutations]**, What are mutations? Silent? Missense? Nonsense? Frame-shift? - **[Mutations]** - a \"mutation\" is a change in the DNA sequence of an organism - **[Silent ]** - A DNA change that doesn\'t alter the amino acid sequence of a protein. - if the codon CUU is changed to CUC, the mutation is silent because both codons code for the amino acid leucine - **[Missense]** - A DNA change that alters a single amino acid in a protein. - For example, sickle cell anemia is caused by a missense mutation - **[Nonsense]** - A DNA change that creates a stop codon, which prevents the protein from being produced entirely - Cystic fibrosis is a disease that may be caused by a nonsense mutation - **[Frame-shift]** - A DNA change that involves the insertion or deletion of one or more nucleotides in a protein-coding sequence. What is cancer? Characteristics? - a group of diseases that occur when cells in the body grow and spread uncontrollably - Characteristics: - **[Uncontrolled growth]** - Cancer cells grow without signals to do so, and they ignore signals that tell them to stop growing or die - **[Genetic changes]** - Cancer cells accumulate changes in their DNA, such as duplications and deletions of chromosome parts. - **[Invasion and]** **[metastasis]** - Cancer cells can invade nearby tissues and organs, and spread to other parts of the body through the blood or lymphatic system - **[What is metastasis?]** - The spread of cancer cells from the place where they first formed to another part of the body. - **[Nutrient use]** - Cancer cells use different nutrients than normal cells, - **[Blood vessel growth]** - Cancer cells signal blood vessels to grow toward tumors - **[Immune system evasion]** - Cancer cells can hide from the immune system, or trick the immune system into helping them stay alive. **[Where can they occur?]** - skin, - bones, - blood vessels, - muscles, - lungs, - kidneys, - immune system **[How is cancer treated?]** - **[Surgery:]** An operation to remove the cancer. Surgery is most effective when the cancer is localized and hasn\'t spread. - **[Chemotherapy:]** Uses drugs to kill cancer cells. Chemotherapy can be given as pills, in veins, or both. - **[Radiation therapy:]** Uses high-energy rays to kill cancer cells and shrink tumors. - **[Hormonal therapy:]** Blocks cancer cells from getting the hormones they need to grow. **[How can cancer be possibly prevented?]** - Avoid carcinogens (tobacco) - Melanoma (UV rays damage - Excessive drinking - Eating a Protective Diet Why are highly specialized cells not a cancer risk? - they are usually programmed to perform a specific function, have limited capacity for division, and often undergo a process called \"differentiation\" - **[Differentiation]** - Differentiation is where they lose the ability to rapidly proliferate once they mature, making it significantly less likely for them to develop uncontrolled growth characteristics that define cancer Why are hereditary cancers dangerous? - YOU CAN'T GET CANCER FROM GENES - You can have a predisposition from something - Born with certain forms of certain genes you can get cancer - **[Breast Cancer]** - **[Recessive autosomal alleles (one is inherited and the other is needed)]** - **[BRCA1 ]** - **[BRCA2]** - **[Retinoblastoma (Eye tumor)]** - Rb gene -- Tumor suppressor gene - Need both mutations in both alleles (one from Mom and one from Dad) to develop this type of cancer - Usually, only one eye - Children inheriting often in both eyes **[What do cancer cells do with telomerase?]** - Cancer cells utilize telomerase to maintain the length of their telomeres - Cancer cells turn on telomerase - A blue and green line with black text Description automatically generated **[What is leukemia?]** - **a type of cancer that affects blood cells in the [bone marrow]** - It\'s caused by the body **[producing abnormal white blood cells too quickly]**, which can impair the bone marrow\'s ability to produce red blood cells and platelets **[What is p53? (\"guardian of the genome\")]** - P53 is a protein that regulates cell division and cell death, and is often called the \"guardian of the genome\" - Stops cell cycle - Activities repair enzymes - If fails, destroys cell - Prevents cells with damaged DNA from dividing, which helps prevent tumors **[What are proto-oncogenes?]** - a normal gene that controls cell division by regulating the cell cycle that becomes an oncogene if it is mutated - makes p53 unavailable **[What is angiogenesis?]** - Angiogenesis is the process of **[new blood vessels forming from existing blood vessels]** - **[What does it do to the body]** - **[Wound healing:]** Angiogenesis is an important part of the wound healing process. - **[Supplies oxygen and nutrients:]** Angiogenesis supplies oxygen-rich blood and nutrients to organs and tissues. - **[Cancer growth:]** Angiogenesis is a major factor in the growth and spread of cancer. New blood vessels provide oxygen and nutrients to cancer cells, allowing them to grow and spread to other parts of the body. - Epithelial cells **[What are antioxidants?]** - Antioxidants are **[substances that protect cells from damage by neutralizing free radicals]**