BIOL 1000: Cell Cycle, DNA Replication - PDF

Certainly! Here's the converted markdown format of the provided text: ## 10/19/2022 ### Mitosis and Cytokinesis Cytokinesis in plant cells begins with the formation of a cell plate. * Rigid cell walls outside plasma membrane do not permit furrowing. * Many small membrane-bounded vesicles. *...

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Here's the converted markdown format of the provided text: ## 10/19/2022 ### Mitosis and Cytokinesis Cytokinesis in plant cells begins with the formation of a cell plate. * Rigid cell walls outside plasma membrane do not permit furrowing. * Many small membrane-bounded vesicles. * Eventually fuse into one thin vesicle extending across the mother cell. * The membranes of the cell plate become the plasma membrane between the daughter cells. * The space between the daughter cells becomes filled with the middle lamella. * Daughter cells later secrete primary cell walls on opposite sides of the middle lamella. ### Cytokinesis in Plant Cells Image: Microscopic image showing cell plate formation in dividing plant cells, with labels indicating cell plate formation, daughter nucleus, vesicles containing membrane components. **Components:** * Daughter Cells * Nucleoli * Daughter Nucleus * Vesicles containing membrane components fusing to for Cell plate --- ## 10/19/ ### Causes of Cancer Image: Diagram illustrating causes of cancer, including effects of growth factor and stimulatory pathways, with labels for receptor protein, proto-oncogene, inhibitory pathway. **Components:** * Growth Factor * Receptor Protein * Stimulatory Pathway * Proto-oncogene * Oncogene * Inhibitory Pathway * Tumor Suppressor Gene ### Cancer Cells vs. Normal Cells **Table 9.2 Cancer Cells Versus Normal Cells** | Cancer Cells | Normal Cells | | --------------------------- | ----------------------- | | Nondifferentiated cells | Differentiated cells | | Abnormal nuclei | Normal Nuclei | | Do not undergo apoptosis | Undergo apoptosis | | No contact inhibition | Contact inhibition | | Disorganized, multilayered | One organized layer | | Undergo metastasis | | Image: Microscopic image of what the cells look like in a petri dish. --- ## 10/19/2022 ### The Cell Cycle and Cancer * Characteristics of Cancer Cells: * Lack differentiation. * Are non-specialized. * Are immortal (can enter cell cycle repeatedly). * Have abnormal nuclei. * May be enlarged * May have abnormal number of chromosomes. * Often have extra copies of genes. * Do not undergo apoptosis. * Normally, cells with damaged DNA undergo apoptosis. * The immune system can also recognize abnormal cells and trigger apoptosis. * Cancer cells are abnormal but fail to undergo apoptosis. ### What are some treatment strategies for cancer? * Chemotherapy * Targeted: Stops/interferes with cell division, (normal cells too!) * Non-targeted: * Directed specifically towards the cancer cells (chemicals). * Monoclonal antibodies *are attached to these * Surgery * Proton Therapy * Radiation (target specific types of cancer cells) --- ## 10/19/2022 ### Ch. 12 Molecular Biology of the Gene * (sections 1 and 2) * What are chromosomes? Chromosome Structure and function * Before we move them lets determine their significance. $\text{chromosome: long strand of DNA} \ (A, G, C, T, S)$ That carries genetic info $\text{gene: a shorter specific region} \ (Of A, G, C ,T (DNA) \text{ that are the info for making a protein})$ There are many genes on a chromosome. ### 3.5 Nucleic Acids * Nucleic acids are polymers of nucleotides. * Two varieties of nucleic acids: * DNA (deoxyribonucleic acid) * Genetic material that stores information for its own replication and for the sequence of amino acids in proteins * RNA (ribonucleic acid) * - Working copy (temporary) of DNA gene * Perform a wide range of functions within cells which include protein synthesis and regulation of gene expression --- ### 10/19/2022 ### Structure of a Nucleotide 7 both RNA & DNA Each nucleotide is composed of three parts: * A phosphate group * triphosphate * A pentose sugar * 5 carbons * A nitrogen-containing (nitrogenous) base * There are five types of nucleotides found in nucleic acids. * DNA contains adenine, guanine, cytosine, and thymine. * RNA contains adenine, guanine, cytosine, and uracil. * Nucleotides are joined together by a series of dehydration synthesis reactions to form a linear molecule called a strand. Can you identify the parts? Image: structure of nucleotide, and deoxyribose versus ribose Component * Phosphate $PO_4$ * Sugar tells diff btwn RNA & DNA by ribose & uracil * Bases are the info. --- ### 10/19/2022 Structure of DNA and RNA * The backbone of the nucleic acid strand is composed of alternating sugar-phosphate molecules. * RNA is predominately a single-stranded molecule. * DNA is a double-stranded molecule. Double helix * DNA is composed of two strands held together by hydrogen bonds between the nitrogen-containing bases. The two strands twist around each other to form a double helix. * Adenine hydrogen bonds with thymine * Cytosine hydrogen bonds with guanine * The bonding between the nucleotides in DNA is referred to as complementary base pairing. $Covalent \ bonds \ make \ a \ strand \ of \ DNA \ (RNA)$ $H \ bonds \ It \ bends \ make \ the \ Helix \ $ Image: diagram featuring DNA structure and complementary base pairing. Key points: * It Bonds * Double Helix * Backbone * $100\%$ * Equal amount of base pair rules * If there is 20°% T * 20°% A * $60\%$ G & C * $40\%$ --- ### 10/19/2022 ### Semiconservative Replication Image: Illustration of the Semiconservative Replication Process. cell is reproducing This is S phase $\downarrow$ Interphase I old & I newly synthesized strand in each new Helix ### Replication of DNA Eukaryotic Replication - Abit different for prokaryotes * DNA replication begins at numerous points along each linear chromosome $specific \ points$ $(ORI)$ * DNA unwinds and unzips into two strands * Each old strand of DNA serves as a template for a new strand the pattern * Complementary base-pairing forms a new strand paired with each old strand (template) * Requires enzyme $\text{DNA polymerase}$ ($DNA \ pol$) makes polymers --- ### 10/19/2022 ### Prokaryotic versus Eukaryotic Replication Illustration: Diagrams comparing DNA replication in prokaryotes and eukaryotes.  prok: * Origin of Replication (ORI) Euk: * Very Long Chromos. * Replication stops at already copied section * Many ORL sites * Makes DNA Syntheses faster ### Aspects of DNA Replication Illustration: Series of diagrams explaining the steps in DNA replication. 1. DNA Helix is unwound $\uparrow$ 2. primer is added small $\downarrow$ 3. continues adding 4. bases until DNAis all copied DNA: Strands Run in OPP directions A few more steps on the lagging strand: Image: series of diagrams explaining aspect of DNA replicaitons * A primer is added * DNA is copied but its small piece. * The Okazaki Fragments are not correted to each other --- ### 10/19/2022 ### Chromosomes in Us What does ploidy mean? * Diploid (2n) humans 2 sets diploid * n= a set of chromos. $\downarrow$ * Haploid (n) 1n Humans only Egg Isperm are haploid. all prok: bacteria are haploid ### 9.4 Prokaryotic Cell Division * **The prokaryotic chromosome is** is a circular ring of DNA * Folded up in an area called the nucleoid * 1,000 X the length of cell * Replicated into two rings prior to cell division see oreo slide on ORI * Replicated rings attach to the plasma membrane * Binary fission. : new bacteria. * Splitting in two * Two replicate chromosomes are distributed to two daughter cells attached to pl. memb * Produces two daughter cells identical to original cell - asexual reproduction\ * No change in genetics **.** --- ### 10/19/2022 **Binary Fission- how bacteria reproduce.** Illustration: Diagrams showing the stages of binary fission in bacteria. Components are: * Cell walls * Plasma membrane * Cytoplam * Chromosome ### **Table 9.3 Functions of Cell Division** | Type of Organism | Cell Division | Function | | -------------------- | ---------------------- | ---------------------- | | Prokaryotes | | | | Bacteria and archaea | Binary fission | Asexual reproduction | | Eukaryotes | | | | Protists | Mitosis and cytokinesis | Asexual reproduction | | Other | | | Fungi plants animals |Mitosis and cytokinesis | Development, growth, and repair | I hope this is helpful!