BIOS251 Weeks 3-4 Outline-Review (1) PDF

**[BIOS251 -- Weeks 3 & 4 Outline/ Exam 2 Review Guide]** **[Week 3 Concepts]** I. **Principles of Cell Theory (C150)** - The smallest structure capable of carrying out life processes - Every organism is made up of one or more cells - Cells can only form from pre-existing cel...

**[BIOS251 -- Weeks 3 & 4 Outline/ Exam 2 Review Guide]** **[Week 3 Concepts]** I. **Principles of Cell Theory (C150)** - The smallest structure capable of carrying out life processes - Every organism is made up of one or more cells - Cells can only form from pre-existing cells a. **Organization of cells** - Prokaryotic cells -- cells without an organized nucleus - Eukaryotic cells -- cells with an organized and well defined nucleus b. **Four structures common to most cells** - Plasma (cell) membrane -- separates internal and external environments - DNA -- genetic material that controls an organism's composition, replicates the cell - Cytoplasm -- can be divided into two portions. - Cytosol -- the liquid portion - Organelles - Ribosomes -- the site of protein synthesis - **Eukaryotic Human Cells**Cytoskeleton- intracellular support, used in cell movement, moves organelles - Cells - Composed of plasma (cell membrane), cytoplasm, cytosol, nucleus, A diagram of cell structure Description automatically generatedcytoskeleton - **cytosol** is the clear gel within the cell sometimes referred to as **intracellular fluid (ICF)**, whereas **cytoplasm** is all the fluid and components between the nucleus and the cell membrane. The cytoplasm includes the cytosol as well as the cytoskeleton c. **Gamete and Somatic Cells** - Gamete (sex) cells -- cells used for reproduction (sperm and ovum). Replicate via meiosis. - Somatic (body) cells -- all other cells in the body. Replicate via mitosis. II. **Introduction to Cell membranes and their function (C151)** - Functions of the cell membrane - Serves as a barrier protecting the cell's inner content from the extracellular environment - Anchors the cytoskeleton - Shapes the cell - Allows cell "communication" through the passage of chemicals - Movement of essential molecules into cells - Removal of waste from cells - Made from a phospholipid bilayer - Hydrophilic (water "loving") heads - Hydrophobic (water "hating") tails - Molecules embedded in phospholipid bilayer: - Transmembrane proteins (cross the width of the membrane touching both internal and external surfaces) - Peripheral proteins (only found on one surface) - Cholesterol -- creates the fluid mosaic model that gives the cell both a structure as well as a flexibility - Sugars - Glycolipids, Glyocoproteins  - Plasma Membrane Proteins - Integral -- found to travel the entire width of the membrane touching both the internal and external surfaces. - Examples: Ion channels, proton pumps - Channel proteins -- allow ions to cross the membrane from one side to another - Carrier proteins -- transport specific substances from ones side of the plasma membrane to the other - Receptor proteins -- recognize and bind to specific molecules called ligands - Cell Identity Markers -- allow the cell to be identified and distinguished by the immune system - Na+/K+ ATPase pump -- maintains an electrochemical gradient - Gap Junctions -- form a connection between two cells - Enzymes - catalyzes (speeds up) chemical reactions inside or outside the cell - Cell Adhesion Molecules -- They serve as structural support and stability for a cell. ​ - Peripheral -- found only on the inner or outer surfaces - Examples: - Cadherins - proteins that transport extracellular ligand (chemical) signaling into cells.​ - Cyochrome C - transfer electrons from one protein to another. ​ - Spectrin - protein is in charge of maintaining red-cell shape - Hereditary spherocytosis -- a condition of the red blood cells caused by the absence of the central pallor causing an appearance of the absence of the pale center A diagram of cell membrane Description automatically generated - Other structural components of the cell membrane - Sugars -- provide protection, display signals, and attach cells - Cholesterol -- decreases membrane fluidity, providing "stiffness" to the cell membrane, and insulating the cell from heat. - Phospholipids bilayer - Bilayer means that there are two layers of phospholipids next to each other - Modified triglycerides containing glycerol and two fatty acids plus a phosphorus-containing group - **Hydrophilic (aka: lipophobic)** heads -- charges chemicals and thus attract water - **Hydrophobic (aka: lipophilic)** tails -- non-charged (or neutral chemicals) and thus repel water - **Mechanisms of movement of materials across plasma (cell) membrane** - **Passive Transport- does not use ATP as an energy source, occurs from high to low concentration (downhill).**  - **Simple Diffusion**- moves along concentration gradient, from higher to lower concentration - **Facilitated Diffusion --** the use of a protein channel to passively move the chemicals across the membrane - **Osmosis**- movement of water across semipermeable membrane from **[low solute concentration to high solute concentration]** - Hypertonicity -- solutions have high ECF osmolarity, water moves out of cell, cell shrinks - Isotonicity -- solutions have same osmolarity, no net movement of water in or out of cell - Hypotonicity -- solutions have low ECF osmolarity, water moves into the cell causing swelling and potential bursting A diagram of different types of blood cells Description automatically generated - **Active Transport**- utilizes energy to move substance against concentration gradient, lower to higher concentration Depends on factors: ATP, Membrane proteins, Concentration of molecules, Membrane potentials - Bulk Transport- uses vesicles to transport large molecules - Endocytosis- transports material into the cell (think Entering) - Phagocytosis -- brings in solids "cell eating" - Pinocytosis- brings in liquids "cell drinking" - Exocytosis -- transports material out of the cell (think Exiting) - **Intracellular & Extracellular fluid** - Intracellular -- also known as cytosol, more gel-like than ECF - Extracellular - sometimes called "tissue fluid", includes plasma - **Membrane potential** - **Voltage:** Any difference in electrical charge (+) or (-) - The uneven distribution of ions across the membrane is controlled by protein pumps and leak channels, resulting in more positive ions outside the cell and more negative ions inside the cell. - **Resting Membrane Potential** - Uneven distribution of ions across a membrane results in voltage known as **resting membrane potential (RMP**)= -70mV - Selective movement of ions across membrane only allows ions to move in one direction. - **Sodium-Potassium Pump** - Moves 3 sodium ions out & 2 potassium ions into cell - Creates a more negative charge in the cell - Muscle and Nervous system rely on it - **Depolarization --** Na+ channels open ad Na+ enters cell making it more positive - **Repolarization** - Na+ channels close, K+ channels open, K+ rushes our of cell - After depolarization & repolarization, the sodium-potassium pump helps the cell return to RMP III. **[Organelles (C152)]** - Organelles -- tiny, organized structures that perform functions within our cells - Means "little organ" - Membranous organelles- covered with lipid membrane. Nucleus, mitochondrion, lysosomes, peroxisomes, Endoplasmic reticulum (smooth & rough), Golgi complex - Non-membranous organelles - generally made of proteins and not covered with lipids IV. 4107101  Nucleolus Dark region at the center of the nucleus made of chromatin (thread-like strands of DNA) ------------------ --------------------------------------------------------------------------------------------- Inclusion Bodies An abnormal structure floating within the cytoplasm Cytoskeleton Provides internal structure, organization, and support & facilitate intracellular transport V. **[Cell Functions (C153)]** - **Central Dogma** -- The use of copying DNA to create a RNA to use as a blueprint for making proteins. 1. Transcription: DS DNA template mRNA "copy" with RNA bases 2. Translation: Ribosome interprets mRNA code to construct protein - Types of RNA - Messenger RNA (mRNA)- genetic code - Transfer RNA (tRNA) -- carries amino acid to ribosome - Ribosomal RNA (rRNA) -- forms ribosome - 3 Steps of Translation 1. **Initiation -- Using a start codon such as AUG** 2. Elongation 3. **Termination -- Using a stop codon such as UGA, UAA, or UAG** - **Protein Synthesis** - Organelles used to make proteins. Proteins play key role in cells. - Genetic code- four nucleotide bases in DNA that become protein sequences in body. Both DNA and RNA are nucleic acids - DNA base pairing: A-T, G-C (Apple -- Tree; Car -- Garage) - RNA base pairing: A-U, G-C - **Cellular respiration** - Cellular respiration is the process by which oxygen and nutrients are used to produce energy and waste - Cellular respiration is a series of metabolic pathways that use sugar such as glucose to produce energy. This energy is stored in the molecule adenosine triphosphate (ATP) and can be used by other enzymes in the cell to perform crucial functions such as active transport and muscle movements. - ATP -- Cell's Energy Transfer Molecule - **ATP**= Adenosine Triphosphate, can be used by other enzymes in the cell to perform critical functions like muscle movement & active transport - Energy is stored in it's phosphate-phosphate bonds. - Most ATP is made in body from **Cellular Respiration** - **Formation of ATP in Chemiosmosis** - **Chemiosmosis** = using the electrochemical H+ gradient to create ATP  - **Cellular respiration** - process that uses oxygen and nutrients to generate energy and waste. It is a direct result of breaking down the sugar in glucose - **Steps of Cellular Respiration** 2. Krebs cycle 3. Electron transport - - - - - - - - **Cell Cycle** - **Interphase** - Consists of S phase (DNA division), G1 & G2 (Gap phases) - Semi-conservative replication: One original strand of DNA - 2 new identical strands - Chromatin -- DNA wrapped around histones to make it condensed - Chromosomes - further wrapping of chromatin (occurs in prophase)  - **Mitosis and Cytokinesis** - Mitosis -- Division of Nucleus - Cytokinesis -- the cell itself divides, resulting in two identical daughter cells - **Steps of Mitosis** - Prophase - nuclear membrane breaks down - chromatin condenses to chromosomes - Spindle fibers form from centrioles - Centrioles migrate to opposite ends of the cell - **[Cross-over occurs where non-sister chromatids share genetic information to create genetic variability of the offspring]** - Metaphase - chromosomes line up in the middle of the cell - Anaphase - chromosomes separate and are pulled to opposite poles of the cells - Telophase - new nuclear membranes form around the two sets of chromosomes - Compare and Contrast Mitosis and Meiosis - exact replication of a cell\'s DNA with the result being an exact copy of the parent cell Diploid (2n), Haploid (n) - MEIOSIS- DNA contains exactly one-half of the number of chromosomes  (which occurs exclusively in reproductive cells). Gametes -- sex cells **[Week 4 Concepts]** I. **Introduction to Main Tissue Types and Tissue Subtypes (C153)** - Histology -- study of tissues - Structure, function, microscopic organization - 4 Major Tissue Types (C-MEN) - Epithelial - line cavities, cover surfaces, forms glands - Connective -- Support, protection of organs & systems, most diverse - Muscle -- body movement & movement of substances through body - Nervous -- conducts electrical impulses, processes information - **Microscopic anatomy, location and functional roles of Epithelial tissue** - Found on the outer surfaces of organs - Avascular so it is dependent on the connective tissue to supply its needs for oxygen and nutrients - Protects organs, controls permeability, provides sensation to external surfaces, and produces specialized secretions - Densely packed together cells - Attached to the connective tissue via Y - membrane - Has an apical (top) of the cell - Named for the - Number of layers: Simple (single), Stratified (multiple), Pseudostratified (fake multilayers), and Transitional (switches between multi and single layers) - Shape of the cell: Squamous (flat), Cuboidal (square), and Columnar (column) shaped - Exocrine Glands and their Modes of Secretion - Merocrine -- released through exocytosis in vesicles (salivary and sweat glands) - Apocrine -- secretions released in apical cytoplasm (mammary glands, ceruminous wax glands in ears) - Holocrine -- secretions via loss of entire cell (oil glands) - - **Microscopic anatomy, location and functional roles of Connective tissue** - Provides structural and physiological support to other tissues, organs, and organ systems - Sparce spread out cells, with extracellular matrix in between - Extracellular matrix is made up of ground substance and the proteins fibers of elastin, collagen, and reticular fibers - Fibroblasts, Mast cells, Macrophages, Mesenchymal cells, Adipocytes - Types of connective tissues: Loose connective tissue, Dense connective tissue, Blood, Cartilage, and Bone - **Microscopic anatomy, location and functional roles of Muscular tissue - see below** - **Microscopic anatomy, location and functional roles of Nervous tissue - see below** - **Primary tissue classifications: Identify on a microscope or picture, describe the characteristics (what it looks like/protein makeup/cell makeup), function (what it does), know at least one location for each.** 1. 2. Epithelium 3. Connective 4. Muscle 5. Nervous - **Specific tissue subtypes: Identify on a microscope or picture, describe the characteristics (what it looks like/is made up of) and know at least one location for each.** 1. **Primary: Epithelium** a. b. Simple squamous epithelium c. Simple cuboidal epithelium d. Simple columnar epithelium e. Stratified squamous epithelium f. Keratinizing stratified squamous epithelium g. Stratified cuboidal epithelium (do not identify) h. Stratified columnar epithelium (do not identify) i. Psuedostratified ciliated columnar epithelium j. Transitional epithelium 2. 3. **Primary: Connective Tissue** k. l. Areolar connective tissue m. Adipose connective tissue n. Dense regular connective tissue o. Dense irregular connective tissue p. Elastic connective tissue ([not] cartilage) q. Hyaline cartilage r. Elastic cartilage s. Fibrocartilage t. Bone u. Blood 4. **Primary: Muscle Tissue** a. Skeletal muscle- voluntary, striated, moves body parts, attaches to bone and/or skin, multinuclear b. Cardiac muscle- involuntary, striated, intercalated discs, found in the heart, uninuclear, have specialized junctions that allow for rapid spread of electrical impulses c. Smooth muscle- involuntary, found in hollow organs, uninuclear 5. **Primary:** Nervous Tissue (no specific tissue subtypes) but be familiar with diagram of neuron and parts of neuron as well as identify neuroglia - **Membranes** - **Four types of Membranes: Cutaneous, Mucous, Serous, Synovial** 1\. [Epithelial membranes] can be comprised of up to three tissue types - Epithelial tissue - Connective tissue - Muscular tissue - **Cutaneous membranes** - composed of a sheet of epithelial tissue that is attached to an underlying layer of connective tissue. - Acts as the first line of defense for the human body - Acts as a barrier that protects against penetration of harmful pathogens - Prevents dehydration of the body by preventing unwanted fluid loss - Also plays a role in thermoregulation - **Mucous membranes** - composed of a sheet of epithelial tissue that is attached to an underlying layer of areolar connective tissue known as the lamina propria - Protects structures from invading pathogens - Lines body cavities that are exposed to the external environment - Respiratory tract - Digestive tract - Urogenital tract - Mucous secretions - Keeps the epithelium moist - Reduces friction - Facilitates absorption and excretion - **Serous membranes** - Serous membranes have three components. - Parietal serosae which lines the walls of the internal body cavity - Visceral serosae which covers the internal organs - Serous fluid which is between the parietal and visceral layers - There are three types of serous membranes, all of which are found in the closed ventral body cavity. - Pleura lines the pleural cavity and covers the lungs - Pericardium lines the pericardial cavity and covers the heart - Peritoneum lines the peritoneal cavity and covers the surfaces of enclosed organs - **Synovial membranes** - composed entirely of loose connective tissue with NO epithelial tissue. These membranes line the cavities of joints and tendon sheaths, and produce a lubricant known as synovial fluid - Lubrication of bone and other components of joints and tendon sheaths - Protects the ends of bones and prevent bone-to-bone contact - Lines joints to provide a cushion that absorbs shock when movement of the joint occurs - **Intercellular Junctions (Cell Junctions)** - General functions of intercellular connections - Provide strength - Resist stress - Communication - Control permeability - Types of intercellular connections - Tight junctions - Form nearly impermeable barrier - Found in epithelial regions where tissue required to be "sealed off" from extracellular fluid - Desmosome - Form very strong structural network, contributes to integrity of cytoskeleton of cell - Resists twisting and stretching, provides strength and withstands mechanical stress. - Hemidesmosomes - Use integrins to connect cells to basal lamina - Anchors epithelial cells to the basement membrane - Gap junctions - Allow ions and other molecules to pass between two cells - Allow two cells to share or exchange cytoplasm - Acts as a "gate" that allows communication between two cells - Provide extremely rapid and direct communication between two cells - Coordinates cellular activities that must occur simultaneously - connexons II. **Tissue growth, modification and repair (C130)** - **Atrophy**- Describes the wasting away or degeneration of cells or tissue - Example; muscle atrophy when one is immobile for an extended period of time - **Necrosis** - The death of most or all cells belonging to a particular organ due to disease, injury, or insufficient oxygen supply to the organ - **Apoptosis** - Programmed cell death that occurs as a result of the organism's normal growth and development process. - **Regeneration**- the process of restoration or growth of cells or tissue, whereby the same tissue replaces damaged/injured/destroyed tissue. - **Fibrosis** - the process of scarring after wound healing. Unlike regeneration fibrosis typically means that the original tissue function is lost. - **Hypertrophy -** an increase in cell size, leading to an enlargement of the entire organ. - **Hyperplasia**- process of rapid cell division and reproduction - **Metaplasia -** permanent or temporary change in the nature of a particular tissue which can often be reversed - **Dysplasia -** presence of any abnormal cells within a particular tissue. Certain dysplasia may be a sign of early stage cancer. - **Steps of Tissue Repair After Injury** - Inflammation - Proliferation - Maturation