Study Guide Cell Cycle PDF

The Cell Cycle Chapter 9 Study Guide Reading and Resources Mader and Windelspecht, Chapter 9 (pp. 147-165) Khan Academy Videos: https://www.khanacademy.org/science/biology/cellular-molecular-biology/mitosis/v/interphase Mitosis (video) | Cell division | Khan...

The Cell Cycle Chapter 9 Study Guide Reading and Resources Mader and Windelspecht, Chapter 9 (pp. 147-165) Khan Academy Videos: https://www.khanacademy.org/science/biology/cellular-molecular-biology/mitosis/v/interphase Mitosis (video) | Cell division | Khan Academy Vocabulary Cell cycle - set of stages that occur between the time when a eukaryotic cell divides, and the resulting cells also divide. Interphase (G1, S, G2) - 90% of the cell cycle is interphase. Cell functions as usual, and depending on the type of cell the amount of time this happens changes. Preparations for mitosis. ​ Adult mammalians cells → 20 hrs​ ​ Embryonic Cells → few hrs Preparations for mitosis occur. ​ ​ G1 - stage before DNA replication ​ ​ ​ Cell recovers from division, grows in size, increases # of organelles, gathers materials. Otherwise, the cells are functioning as normal & respirating. Sometimes cells go into the G0 stage, where they are operating as normal but are not preparing for mitosis. ​ ​ S - stage where DNA replication/synthesis takes place. One DNA turns into two. Double helix is called as chromatid. ​ ​ G2 - stage after DNA replication ​ ​ ​ Cell synthesizes proteins for cell division. Microtubules are formed. ​ ​ Mitosis - The mitotic spindle distributes the “daughter chromosomes” into two “daughter nuclei” ​ Prophase - chromatin condenses and chromosomes are visible. Nucleolus disappears. Spindle begins to assemble. Prometaphase - nuclear envelope breaks down, “chromosomes inside form protein structures called kinetochores.” The kinetochore of each chromatid is attached to a spindle fiber. Metaphase - The chromosomes are in line in the cell that is about to divide, Anaphase - Shortest phase of mitosis, the material from the main cell is split into two identical daughter cells, with a centromere and a chromatid of one double helix. Spindle fibers pull apart the chromatins by attaching to the kinetochores, and pull them to opposite ends of the cell. Telophase - The spindle fibers disappear and new nuclear envelopes form around the daughter cells’s nucleus Cytokinesis - The division of the cytoplasm. Accompanies mitosis in most cells, but not all. If this doesn’t occur, there is a multinucleated cell. Division of cytoplasm starts in anaphase. ​ Animal Cells: A band of actin filaments called the contractile ring starts forming a circular shape in between the two cells, in the cleavage furrow. It slowly constricts the space in between the two daughter cells until they split. Each cell has their share of the duplicated organelles. ​ Plant Cells: In plant cells, instead of cleavage furrowing, a cell wall is built in between the two daughter cells due to the rigid shape of plant cells. DNA - deoxyribonucleic acid, double helix, has genetic information we need. Made up of nucleotides, has information on how to duplicate itself. Histones - Basic protein that serve as spools for the DNA to coil itself around, to create nucleosomes Chromatin - material that chromosomes are made out of, in charge of packaging DNA to be more compact to create chromosomes. Chromosomes - thread like structure made up of DNA, Each human cell has 23 pairs, so 46 total chromosomes. Found in the nucleus. Define physical traits, and gender. Sister chromatids - two identical chromatids that are created during the S phase, they are formed by the replication of the chromosomes. Centromere - The region where the kinetochore is, and this is where the microtubules of the spindle attach to pull apart the chromatids. Kinetochore - a complex of proteins that are on the centromere, where the microtubules of the spindle attach. Centrioles/centrosome - regulates the cell cycle, cylinder shaped and found in pairs- organelle. Creates the spindle fibers during cell division. Mitotic spindle fibers - Proteins that pull apart the chromatids by attaching to the kinetochore located in the centromere. Cleavage furrow - An indentation of the membrane between the two daughter cells. As anaphase is about to end this forms. Cell plate - newly formed plasma membrane that expands until it’s able to fuse with the old membrane. Is made by vesicles fused together. Plants & Fungi. Apoptosis - A type of cell death, a series of steps lead to death in the cell. A method the body uses to get rid of abnormal & unneeded cells. “Programmed cell death”. Can be blocked in cancer cells, so they are harder to terminate. Cancer - cellular growth disorder, cells divide without control → usually due to a mutation that controls the cell cycle. Usually starts out as just some chill growth, and is not very dangerous, but if the cell continues to mutate, and there is more control over the cell cycle, it becomes worse and is able to spread. Oncogene - Proto-oncogenes are codes for proteins that help the cell cycle go like normal, cause the cell cycle to speed up. When mutations occur, they become oncogenes, which are cancer causing. Under constant stimulation, keep promoting cell cycle at a constant fast rate, even when there is no growth factor. Tumor suppressor gene - code for proteins that promote apoptosis, used as a balance for a proto-oncogene. Cause the cell cycle to go slower or stop. A mutation in this gene leads to the cell cycle accelerating at full speed, and not stopping at all. Prokaryotic cell division - reproduce asexually via binary fission. Grow twice as big and then split.  Cell cycle Collaborative Exercise 1.​ Why do cells grow and reproduce? Why are these functions essential to life? Cells grow and reproduce so that way even if a cell happens to die, it’s alright since more can be produced. It’s essential to life because we need cells to live, and if they die without means of reproduction, it makes them fragile to the point where anything could kill us. 2.​ What is the difference between: a.​ Chromatin and chromosomes? ​ Chromatins are what create chromosomes, packing DNA into the shape needed. Chromosomes are tightly coiled DNA that is the end product of this process. b.​ Chromosomes and sister chromatids? Chromosomes replicate and split into sister chromatids in the process of cell division.  c.​ A centriole and a centromere? A centrosome is a cellular structure which houses the centrioles which are an important part of cell division because they make the spindle fibers needed. 3.​ Complete the activity “Cell cycle sequence of events.” a.​ Draw a picture below that shows the key events of the cell cycle. b.​ Which of these events fit into each of the major states of interphase (G1, S, G2)? Use activity: G1- S- G2 - Do later :)  c.​ Which of these events fit into each of the major stages of mitosis (prophase, prometaphase, metaphase, anaphase, telophase)? See chart above. Prophase- Chromosomes become visible, nucleolus disappears, spindle fibers form Prometaphase- kinetochores appear at centromeres, centrosomes start moving apart Metaphase- Chromosomes are pulled to opposite sides, and lined up. Sister chromatids are attached to spindle Anaphase - Sister chromatids move to opposite sides Telophase - nuclear envelope forms around each chromatid, spindle breaks down Cytokinesis - ​ Animal cell: broken through cleavage furrow ​ Plant cell: cell plate separates the daughter cells 4.​ What is cancer? What role do cell cycle checkpoints play in the formation of cancerous cells? Cancer is a mutation that breaks the cell’s ability to decide whether it needs to duplicate more or stop doing that. Proto-oncogenes become oncogenes, and the balance for that (things that promote cell death) are also limited, so the cell cycle balance is completely skewed. There’s a genetically altered cell that spreads and mutates more, either becoming in situ or malignant. The checkpoints play a role in the formation because if the cell is unable to detect whether it has been divided or not, more cells will continue to divide at rapid, and uncontrolled rates.