The Cell - A Summary of Cell Biology PDF

THE CELL 1. POWER HOUSE OF THE CELL nucleus mitochondria centriole golgi apparatus 2. RESPONSIBLE FOR PACKAGING PROTEINS AND SENDING THEM OUT OF THE CELL. nucleus mitochondria centriole golgi apparatus 3. WHERE DNA IS STORED. nucleus mitochondria centriole golgi...

THE CELL 1. POWER HOUSE OF THE CELL nucleus mitochondria centriole golgi apparatus 2. RESPONSIBLE FOR PACKAGING PROTEINS AND SENDING THEM OUT OF THE CELL. nucleus mitochondria centriole golgi apparatus 3. WHERE DNA IS STORED. nucleus mitochondria centriole golgi apparatus WHO DISOVERED THE CELL? Robert Hooke Charles Darwin Albert Einstein Lady Ada 6 PROTEIN CONNEXINS FORMED TOGETHER IS CALLED Connexon Connector Conjugate Conzace MOVEMENT OF SOLUTE FROM GREATER CONCENTRATION GRADIENT TO A LOWER CONCENTRATION GRADIENT Osmosis Diffusion Endocytosis Exocytosis MOVEMENT OF WATER FROM GREATER CONCENTRATION GRADIENT TO A LOWER CONCENTRATION GRADIENT THROUGH A SEMI PERMEABLE MEMBRANE Osmosis Diffusion Endocytosis Exocytosis ENGULFING OF BACTERIA BY A MACROPHAGE IS AN EXAMPLE OF__________ Osmosis Diffusion Endocytosis Exocytosis DNA: ATA ACG TGC MRNA:________________________ DNA: ATA ACG TGC TRNA:________________________ ALLOWS MOVEMENT OF IONS FROM ONE CARDIAC CELL TO ANOTHER Intercalated disc gap junction Axon dendrite MEMBRANE THAT PROTECTS THE HEART Pericardium Periosteum Pleura ribs MEMBRANE THAT PROTECTS THE LUNGS Parietal pleura Visceral pleura Both parietal and visceral pleura none MEMBRANE THAT PROTECTS THE JOINTS synovium bursa Periosteum Synovial fluid EPITHELIUM THAT PROTECTS THE VAGINA Stratified squamous, non keratinizing epithelium Stratified squamous, keratinizing epithelium Simple squamous, non keratinizing epithelium Simple squamous, keratinizing epithelium THE CELL THE CELL Discovered by Robert Hooke during the 1600’s Known as the building blocks of life THE CELL Composed of 4 elements: carbon, oxygen, hydrogen and nitrogen and other smaller elements. Various shapes, sizes and functions MICROSCOPIC ANATOMY OF THE CELL  PARTS OF THE CELL Nucleus Nuclear envelope Nucleoli Chromatin Plasma Membrane Tight Junctions Desmosomes Gap Junctions Cytoplasm Organelles Inclusions PLASMA MEMBRANE Composed primarily of 2 lipid layers arranged tail to tail in which protein molecules float. The polar phospholipid heads lie on inner and outer parts of the cell. Non polar tails lie in the center of the membrane Protein channels regulate passage of substances in and out of the cell Glycoprotein and glycolipid structures are needed for binding to other extracellular structures such as hormone molecules.  PLASMA MEMBRANE Specializations include Microvilli Membrane junctions Desmosomes Tight junctions Gap junctions  MICROVILLI Increases the cell surface area for the absorption for more nutrients to be absorbed. Are tiny, finger like extensions of the plasma membranes that projects from an exposed cell surface  TIGHT JUNCTIONS Are impermeable junctions that bind cells together into a leakproof sheets that prevent substances from passing through the extracellular space between cells. E.g. these junctions prevent enzymes from seeping into the blood stream  DESMOSOMES Anchoring junctions that prevent cells subjected to mechanical stress (such as skin cells) from being pulled apart. These are plaques, buttonlike thickenings of adjacent plasma membranes which are connected by fine protein filaments They prevent cells subjected to mechanical stress from being pulled apart such as heart cells, muscle cells and skin cells  GAP JUNCTIONS 6 proteins (connexin) combined to form a hollow cylinder called connexons. When two connexons appose, they form gap junctions to allow easy exchange of substances. Function mainly allow communication. Heart and embryonic cells  CYTOPLASM Where all other cell components are suspended “factory floor” of the cell Has 3 major components : cytosol, inclusions, and organelles Cytosol- composition of water, salts, sugar, protein etc. CYTOSOL and INCLUSIONS Cytosol – is a semitransparent fluid that suspends the other elements. Inclusions – are chemical substances that may or may not be present, depending on the specific cell type. Most inclusions are stored nutrients or cell products floating in the cytosol. ( lipid droplets, glycogen granules,pigments) ORGANELLES (Cytoplasmic Organelles) Mitochondria Ribosomes Endoplasmic Reticulum Golgi Apparatus Lysosomes Peroxisomes Cytoskeleton Centrioles MITOCHONDRIA Power house of the cell Consists of double membrane side by side Outer- smooth Inner- shelf like protrusions called CRISTAE Primary function is to produce ATP  RIBOSOMES Dark lobed bodies that sites protein synthesis Some float and manufacture protein Some attach to membranes forming the rough endoplasmic reticulum Actual site of protein synthesis  ENDOPLASMIC RETICULUM System of fluid-filled cisterns (tubules and canals) that coil and twist throughout the cytoplasm. Carries primary proteins Rough and Smooth ER Serves mini circulatory system for the cell because it provides a network of channels for carrying substances from one part to another cell ENDOPLASMIC RETICULUM Smooth Reticulum No function in protein synthesis Fat synthesis and breakdown Detoxification of drugs and pesticides ENDOPLASMIC RETICULUM Rough Endoplasmic Reticulum Cell’s membrane factory Produce enzymes needed for digestion Golgi Apparatus Its major function is to modify, packaged protein and ship protein in specific ways Generally found close to the ER Known as the traffic director for cellular proteins Flattened membranous sacs that are associated with tiny vesicles (secretory vesicles) LYSOSOMES Contains digestive enzymes capable of digesting worn out or no usable cell structures and most foreign substances Function as cellular “stomach” Suicide bags Abundant in wbc (phagocytes) for the destruction of bacteria and other harmful substances PEROXISOMES Contains catalase that converts hydrogen peroxide to water Contains other peroxidases that oxidizes harmful substances to a non toxic substance Detoxify harmful and poisonous substances Most important function is to disarm free radicals They replicate on their own just like the mitochondria Numerous in liver and kidney cells which are very active in detoxification  CYTOSKELETON Acts as the cells’ bones and muscles Determines cells’ shape and supports other organelles Provides machinery for transport needed for intracellular transport Made up of proteins called MICROTUBULES, INTERMEDIATE FILAMENTS and MICROFILAMENTS MICROTUBULES Determine shape of the cells and organelle distribution Kinesin- towards the cell Dynein- towards the membrane INTERMEDIATE FILAMENTS Help form microfilaments Provide internal wires to resist pulling forces on the cell MICROFILAMENTS Involved in cell motility and in producing changes in cell shape Actin and myosin CENTRIOLES Direct the formation of mitotic spindle during cell division Rod shaped bodies found close to the nucleus Some have projections called cilia and flagellum NUCLEUS Headquarters; Control Center Where highest DNA (deoxyribonucleic acid) concentration is found Substructures include: Nuclear envelope Nucleoli Chromatin  NUCLEAR ENVELOPE 2 layers include the inner and outer membrane In between these 2 is fluid filled called MOAT Selectively permeable thru the nuclear pore Encloses a gel like fluid called nucleoplasm NUCLEOLI Where ribosomes are assembled Ribosomes are organelles that serve as site of protein synthesis  CHROMATIN These are loose network of bumpy threads of protein and DNA During cell division, they aggregate to form CHROMOSOMES. CELLULAR ACTIVITY Cell physiology (membrane transport) DEFINITION OF TERMS Solution- homogenous mixture of 2 or more components Solvent- dissolving medium Solute- substances present in smaller amounts or substances being dissolved MEMBRANE TRANSPORT Diffusion Osmosis Filtration Facilitated diffusion Active transport Endocytosis Exocytosis DIFFUSION Is the process by which molecules (and ions) move away from areas where they are more concentrated to areas where they are less concentrated FACILITATED DIFFUSION Substances move their own concentration gradient to a protein membrane through a transport channel or a gate. process of spontaneous passive transport of molecules or ions acros s a cell's membrane via specific transmembrane integral proteins. OSMOSIS Diffusion of water through a selectively permeable membrane such as the plasma membrane  Osmotic pressure- is the tendency of a solution to hold or “pull” water into it. Tonicity – the ability of a solution to change the size and shape of cells by altering the amount of water they contain. Isotonic – (5% glucose, 0.9% saline) same solutions as cells do. Hypertonic – a solution that contain more solutes hypotonic – a solution contains fewer solutes FILTRATION Process by which water and solutes are forced through a membrane or capillary wall by fluid or hydrostatic pressure. Large molecules are held back from the membrane. Seen in the kidneys to filter important electrolytes and return to the circulatory system. ACTIVE TRANSPORT Cell uses energy through ATP degradation to facilitate transport of substances through a channel or a membrane directly. BULK TRANSPORT (vesicular) ENDOCYTOSIS EXOCYTOSIS Engulfing of substances in the Movement of substances outside of the cell plasma membrane forming a vesicle through the migration of a vesicle to the plasma membrane. to the cell. Also known as phagocytosis PROTEIN SYNTHESIS  DEOXYRIBONUCLEIC ACID (DNA) The blue print for protein synthesis Gives the information for building proteins Composed of Bases: Adenine Thymine Guanine Cytosine Composed of Sugar phosphate backbone Genes- segment of DNA RIBONUCLEIC ACID The decoder and messenger of DNA information needed for protein synthesis Has a ribose sugar instead of deoxyribose Uses uracil instead of thymine as a base Messenger RNA - transcription Ribosomal RNA- formation of ribosomes Transfer RNA- translation CELL DIVISION MITOSIS MITOSIS Division of the nucleus Results in the formation of two daughter cells INTERPHASE Process of DNA replication Doubling of chromosomes PROPHASE Bar bodies called chromosomes appear Formation of mitotic spindle and movement to the opposite poles Disappearance of nuclear envelope and nucleoli METAPHASE Chromosomes cluster and align at the metaphase plate (the center of the spindle midway between the centrioles) Straight line of chromosome is seen ANAPHASE Chromatids split Chromatids are now called chromosomes Slowly assemble and move toward the opposite ends of the cell TELOPHASE Prohase in reverse Chromosomes in opposite ends of the cell uncoil to become threadlike chromatin again BODY TISSUES BODY TISSUES 1. Epithelial 2. Connective 3. Muscle 4. Nervous 1. EPITHELIAL TISSUES Covering, lining , and glandular tissues of the body For protection, absorption, filtration and secretion CHARACTERISTICS OF EPITHELIUM They fit closely together to form continuous sheets They always have one free surface or edge, sometimes may have modifications called cilia or microvilli Lower surface rests on a basement membrane They have no blood supply or avascular, relies on diffusion from underlying capillaries They regenerate easily CHARACTERISTICS OF EPITHELIUM They fit closely together to form continuous sheets They always have one free surface or edge, sometimes may have modifications called cilia or microvilli Lower surface rests on a basement membrane They have no blood supply or avascular, relies on diffusion from underlying capillaries They regenerate easily CLASSIFICATION OF EPITHELIUM SIMPLE STRATIFIED SIMPLE SQUAMOUS EPITHELIUM Forms membranes for filtration or exchange of substances by rapid diffusion Capillaries Alveoli Serous membranes SIMPLE CUBOIDAL EPITHELIUM Found on glands for secretion Ovaries Kidney tubules Salivary glands pancreas SIMPLE COLUMNAR EPITHELIUM Goblet cells- production of mucus Whole digestive tract Mucous membrane  PSEUDOSTRATIFIED COLUMNAR EPITHELIUM Some of its cells are shorter thus giving a false impression For absorption and secretion Trachea and upper respiratory tract Some are ciliated that traps debris and propel mucus upward and away from the lungs CLASSIFICATION OF EPITHELIUM SIMPLE STRATIFIED STRATIFIED SQUAMOUS EPITHELIUM Keratinizing or non keratinizing Found on skin, mouth, vagina, anus, esophagus Receives good deal of abuse or friction STRATIFIED CUBOIDAL AND COLUMNAR EPITHELIUM Found on large glands, sweat glands, testes and ovaries for production of hormones For secretion TRANSITIONAL EPITHELIUM Highly modified stratified squamous epithelium Urinary bladder, ureters and urethra stretchable  Glandular Epithelium A gland consist of one or more cells that make and secret a particular product (secretion) typically contain protein in an aqueous fluid. Endocrine gland – ductless gland, their secretions (hormones) diffuse directly into the blood vessels Exocrine gland – retains their ducts (oil glands, sebaceous gland, liver and pancreas)  CONNECTIVE TISSUE Connects body parts Most abundant and widely distributed of all tissue types For protecting, supporting and binding together other body tissues Well vascularized except tendons, ligaments and cartilages Contain extracellular matrix and other nonliving substances Distiguishing features : ground substance and fibers (collagen and elastic fibers) DENSE CONNECTIVE TISSUE Bone – “osseous”, composed of osteocytes sitting in cavities called lacunae (surrounded by a very hard matrix and calcium salts, plus collagen fibers) Cartilage – less hard, more flexible than bone (Hyaline cartilage,fibrocartilage, elastic cartilage) Hyaline cartilage- most abundant cartilage in the body Tendons- attach skeletal muscles to bones Ligaments- connect bones to bones at joints  LOOSE CONNECTIVE TISSUE Areolar tissue- cobweb like substance. Packs internal organs together in their proper positions. Adipose tissue(fat)- composed of signet ring cells, for protection and heat and energy production Reticular Connective tissue – it forms the stroma or internal framework of an organ. The stroma can support many free blood cells (lymphocytes) in lymphoid organs, spleen, and bone marrow.  MUSCULAR TISSUES Responsible for movement Voluntary and involuntary Cardiac muscle- contains intercalated discs which allow free passage of ions from one cell to another NERVOUS TISSUE Responsible for reception and transmission of electrochemical signals Responsible for producing memory and distinction Responsible for detecting changes and responses Neurons Supporting cells that insulate, support and protect BODY MEMBRANES 1. EPITHELIAL MEMBRANE Covering and lining membrane Cutaneous Membrane Mucous membranes Serous membranes  CUTANEOUS MEMBRANE Composed of keratinizing squamous epithelium Dermis composes of mainly connective tissue Dry membrane MUCOUS MEMBRANE (MUCOSA) Composed of epithelium resting on a connective tissue membrane called lamina propria Lines all body cavities and hollow organs Wet epithelium For absorption and secretion SEROUS MEMBRANE A layer of simple squamous epithelium resting on areolar connective tissue Occur in pairs: parietal (outside) and visceral (inside) In between is a so called fluid (serous fluid), secreted by both membranes Allows organs to slide easily without friction Peritoneum Pericardium pleura  2. CONNECTIVE TISSUE MEMBRANE Synovial membrane- composed of soft areolar connective tissue Does not contain epithelial cells They line the fibrous capsules of surrounding joints where they produce a lubricating fluid Bursa or tendon sheath THANK YOU!