Cellular Level Biology Notes PDF

Professor Lindboom-Broberg (LB) Cells & Organelles Cell Theory Cellular Organelles Levels of Organization  Remember these? Introduction to Cells  Cell Basics  Smallest unit considered living by science  Size = ~0.1 mm in diameter  Function based on underlying chemistry of their pa...

Professor Lindboom-Broberg (LB) Cells & Organelles Cell Theory Cellular Organelles Levels of Organization  Remember these? Introduction to Cells  Cell Basics  Smallest unit considered living by science  Size = ~0.1 mm in diameter  Function based on underlying chemistry of their parts Membranes, organelles, protein production process,  Cell theory 1. Cells are the basic unit of all life 2. All biological organisms are made up of cells 3. All cells come from pre-existing cells Introduction to Cells  Start: 1 cell (ovum)  Adult: 37.2 trillion cells  Cellular division, differentiation, and reliance  Cellular Differentiation: A process by which generalized cells gain specialized functions Cellular A&P  Cells provide small compartments  Storage, transport, separation, filtration, regulation, etc.  The body is 2/3s water (H2O) Cells dictate its distribution as well as those items dissolved in it  Body fluid distribution  Plasma Membrane: Layer separating outside vs. inside of cell  Cytoplasm: The internal contents of the cell  Intracellular fluid: Fluid content inside the cell (= cytosol)  Extracellular fluid: Fluid content outside of the cell Cellular A&P  Organelles: “little organs”  Units within a cell with specialized functions  Two categories  Non-membranous Not completely enclosed by membranes In direct contact with cytosol  Membranous Enclosed in a phospholipid membrane Isolated from cytosol Cellular A&P Organelles & Structures  Plasma Membrane  Cytoplasm / Cytosol  Cytoskeleton  Centrosome / Centriole  Ribosome  Endoplasmic Reticulum (ER)  Rough  Smooth  Golgi Apparatus  Lysosome / Peroxisome  Mitochondria  Nucleus Cell – Plasma Membrane  Composed of:  Phospholipid bilayer  Cholesterol  Proteins 1. Integral 2. Transmembrane 3. Peripheral  Glycocalyx Cell – Plasma Membrane  Phospholipid bilayer  Measures 6–10 nm (1/10,000 of a cell)  Two layers of phospholipids Hydrophilic heads at membrane surface Hydrophobic tails facing each other on the inside  Phospholipids interspersed with cholesterol molecules Functions to “stiffen” the plasma membrane Cell – Plasma Membrane  Proteins  Integral proteins Permanently attached Often span entire cell membrane (called transmembrane proteins) Can transport water or solutes  Peripheral proteins Temporarily attached to cell membrane inner or outer surface May have regulatory or enzymatic functions Cell – Plasma Membrane  Glycocalyx  Layer of carbohydrates outside of cell Attached to proteins or lipids  Functions Cell recognition Binding to extracellular structures Lubrication of cell surface Cell – Cytoskeleton  Cytoskeleton  No Membrane  Functions Skeleton / internal framework Transportation highway  Components are proteins: 1. Microfilaments 2. Intermediate filaments 3. Microtubules Cell – Cytoskeleton  Kinesin & Dynein movement on Microtubules Cell – Cytoskeleton  Centrioles  No membrane  Composed of microtubules  2 centrioles = 1 centrosome  Control movement of DNA strands during cell division Cells without centrioles cannot divide – Red blood cells – Skeletal muscle cells Cell - Ribosomes  Ribosomes  No membrane  Made of two subunits of ribosomal RNA (rRNA) & protein  Responsible for translation & protein synthesis  Two classifications (based on location) Free ribosomes – Found throughout cytoplasm – Manufactured proteins enter cytosol Bound or fixed ribosomes – Attached to rough endoplasmic reticulum – Synthesize proteins for export out of cell Cell - ER  Endoplasmic reticulum (ER) Cell – Golgi Apparatus Cell – Lysosomes Cell – Mitochondria Cell – Nucleus Cell – Nucleus  DNA  Stored in the nucleus (eukaryotes)  Instructions for RNA / protein synthesis  One cell DNA ≈ 2 meters Double Helix Nucleosomes Chromatin Chromosome Cellular A&P Organelles & Structures  Plasma Membrane  Cytoplasm / Cytosol  Cytoskeleton  Centrosome / Centriole  Ribosome  Endoplasmic Reticulum (ER)  Rough  Smooth  Golgi Apparatus  Lysosome / Peroxisome  Mitochondria  Nucleus  Professor Lindboom-Broberg (LB) Transcription & Translation DNA  RNA  Protein DNA  Central Dogma  DNA is transcribed into RNA  RNA is translated into amino acids (protein) DNA  Gene  Functional unit of heredity which is a determinant for a characteristic  Contains all the DNA nucleotides to produce a specific product  Size varies (~3003000 nucleotides) DNA  Transcription  The process of making an RNA complement to a given gene Complement is called messenger RNA (mRNA)  Translation:  The conversion of an mRNA sequence into an amino acid sequence  Translating the nucleic acid code into the amino acid code (using ribosome)  Professor Lindboom-Broberg (LB) Membrane Transport How do substances move in and out of the cell? Plasma Membrane  Selectively permeable  Permits free passage of SOME materials and restrict others 1. Characteristics of material to pass – Size – Molecular shape – Lipid solubility – Electrical charge – Other factors 2. Characteristics of cell membrane – What lipids and proteins present – How components are arranged Diffusion  Diffusion  Concentration Gradient  Solution  Solvent, Solute Osmosis Tonicity  Water moves across the membrane in order to equalize solute concentrations Membrane Transport  Membrane transport 1. Passive (no ATP required) Diffusion – Simple – Facilitated Carrier-mediated transport 2. Active (requires ATP) Carrier-mediated transport Vesicular transport Passive Transport - Diffusion EXTRACELLULAR FLUID Passive Transport - Carrier-Mediated Active Transport - Carrier-Mediated Active Transport - Vesicular Transport  Endocytosis  Pinocytosis  Phagocytosis  Exocytosis  Professor Lindboom-Broberg (LB) Cell Cycle 1  Trillions of cells (human development) Mitosis & Meiosis Cell Cycle  Cell Division: Cellular reproduction 1. Mitosis Somatic cells 2. Meiosis Sex/Germ cells  Cells have varying life spans and abilities to divide  Apoptosis: Genetically controlled cell death Cell Cycle  Mitosis  Cells: Somatic  Daughter Cells: 2  Chromsome #: Diploid  Function Growth Replace dead cells  Three stages Interphase Mitosis Cytokinesis Cell Cycle  Meiosis  Cells: Sex / Germ  Daughter Cells: 4  Chromsome #: Haploid  Function Sexual reproduction Meiosis I  Three stages Interphase Meiosis 1 Meiosis 2 Meiosis II Meiosis  Mitosis  Meiosis Cancer  Cell Cycle  To keep cell division controlled, there are many stop & go signals STOP signals allow processes to complete before moving on GO signals allow the cell to continue onto the next step If these signals are not followed, issues can arise  If DNA is damaged or mutates, STOP & GO signals can be altered Tumor: Uncontrolled, cell division Cancer: Uncontrolled, harmful cell division – Cancerous cells compete with normal cells for resources Cancer  Tumor (neoplasm)  Mass or swelling produced by abnormal cell growth and division 1. ​Benign tumor  Non-cancerous  Cells remain within original tissue  Seldom a threat  Can be removed surgically if necessary Cancer 2. Malignant tumor  Cancerous  Cell growth invades surrounding tissue & disrupts function  Released chemicals stimulate blood vessel growth (angiogenesis) to tumor area Increased growth rate  Metastatisis: Cells migrate to other areas and establish new tumors