Cell Theory Reviewer - Gen. Bio. PDF

REVIEWER -GEN. BIO. [WEEK 2 -CELL THEORY] **CELL** -The cell (from Latin cella, meaning **\"small room\"**) -is the basic structural, functional, and biological unit of all known organisms -is the **smallest unit of life.** -often called the \"**building blocks of life**\". -are the **basic u...

REVIEWER -GEN. BIO. [WEEK 2 -CELL THEORY] **CELL** -The cell (from Latin cella, meaning **\"small room\"**) -is the basic structural, functional, and biological unit of all known organisms -is the **smallest unit of life.** -often called the \"**building blocks of life**\". -are the **basic unit of structure in all organisms** and also the **basic unit of reproduction \semi-permeable membrane is defined as a type of barrier that only lets certain materials pass through under certain conditions. **CYTOPLASM** -pertains to the fluid portion of the cell which contains the three main structural components: cytoskeleton, organelles and inclusions. -Also called as "soup" of the cell. **CYTOSKELETON** -It is composed of collective network of protein filamentous, thread- like structure called microtubules, microfilaments which produce a strong ability to support and maintain the cell shape. -It is the haemomental framework of the cytoplasm containing protein filament that assist for the organelles to move inside. -helps cells maintain their shape and internal organization  **NUCLEUS** -The nucleus is a membrane-bound organelle that contains the genetic material (DNA) of eukaryotic organisms. -As such, it serves to maintain the integrity of the cell by facilitating transcription and replication processes. -It\'s the largest organelle inside the cell taking up about a tenth of the entire cell volume. **Parts:** 1. **Nuclear Envelope** - a highly regulated membrane barrier that separates the nucleus from the cytoplasm in eukaryotic cells. 2. **Nucleoplasm** - a type of protoplasm that is made up mostly of water, a mixture of various molecules, and dissolved ions. It is completely enclosed within the nuclear membrane or nuclear envelope. 3. **Nucleolus** - is the largest structure in the nucleus of eukaryotic cells. It is best known as the site of ribosome biogenesis. **CYTOPLASMIC ORGANELLES** **ENDOPLASMIC RETICULUM** -is a complex network of flattened sacs and tubes extending from the nuclear membrane to the plasma membrane. It transports substances through the inside of the cell, and synthesizes lipids, enzymes and proteins. **Two types:** - **Rough ER** - an ER with ribosomes on its surface. - **Smooth ER** - an ER without ribosomes on its surface. **RIBOSOMES** -site for protein synthesis. Found attached to rough ER or floating freely in the cytosol. Produced in the nucleolus. **GOLGI BODIES** -are flattened stacks of membranes that modify the proteins (polypeptides) and lipids and then package into a small, membrane-enclosed organelle called a "vesicle". \>A **vesicle** is a self-contained structure consisting of fluid or gas surrounded and enclosed by an outer membrane called the lipid bilayer.  **MITOCHONDRIA** -is the powerhouse of the cell. This is the location wherein energy produces ATP (Adenosine Triphosphate). **VACUOLE** -single membranous sac that plays important roles in the storage of materials, releasing cellular waste products conducting intercellular digestion, and maintaining hydrostatic pressure. **LYSOSOMES** -is a small membrane-bordered structure that contains powerful enzymes necessary for cellular digestion. -Garbage disposal of cell. **GLYCOCALYX** -it is known to be the cell coat that is located in the outer part of the animal cell, its function is cell recognition and cellular adhesion. **PLASTIDS** -Largest organelle in plant cells. These are disk-shaped pigments containing storage organelles found only in plant cells and some photosynthetic protists. -Different Plastids and their coloring pigments - **Chloroplastids** - green pigment - **Chromoplastids** - colored pigments like red, yellow, and orange - **Leucoplastids** - white and colorless pigments **CENTROSOME** -is an organelle that is the main place where cell microtubules are organized. -Also, it regulates the cell division cycle, the stages that lead up to one cell dividing in two. **CENTRIOLE** -is a cylindrical organelle composed mainly of a protein called tubulin. Centrioles are found in most eukaryotic cells. -A bound pair of centrioles, surrounded by a shapeless mass of dense material, called the pericentriolar material, makes up a structure called a centrosome.  **[WEEK 4-EUKARYOTIC AND PROKARYOTIC CELLS]** **PROKARYOTES** -means "before the nucleus" -All prokaryotes are single cell organisms that are the smallest and metabolically diverse forms of life. **EUKARYOTES** -organisms that are consist of free-living cells; capable to become independent, the others also made up of trillions of cells working together as a team or as a unit. -eukaryotic cell contains visible organelles and evidently a true nucleus. **COMPARISON BETWEEN PROKARYOTIC CELL(P) AND EUKARYOTIC CELL(E)** - **Cell type** P E - **Nucleus** P E - **Number of Chromosomes** P -Contain of nucleic acid, one-but not true chromosome; plasmids E -With nucleic acid and protein, more than one - **Features of genetic material DNA** P -Not organized, DNA molecules are packed in a region, nucleoid but not the nucleus E -Organized, packed into chromosomes located inside the nucleus - **Organelles** P -Incomplete organelles; lack of mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes E -Complete organelles - **Sexual reproduction** P -No meiosis, transfer of DNA fragments, absent conjugation E -Meiosis and fusion of gametes - **Cell Wall** P -Usally chemically complexes, contain muriatic acid E -Only in plant cell and fungi, chemically simplest without muriatic acid - **Chloroplast** P -Absent chlorophyll scattered in the cytoplasm E -Present only in plants and photosynthetic protists - **Flagella** P -Composed of only one fiber submicroscopic in size, lack of tubular feature. E -Usually arranged a nine doublets, bounded membrane microscopic in size.  **[HUMAN CELLS -SPECIALIZED CELLS]** **SPECIALIZED CELLS** -Cells designed to carry out a certain role -Cells which have specific components and a specific structure **RED BLOOD CELL** -Red blood cells are cells found in the blood -They contain haemoglobin which carries oxygen around the body **\>HOW IS IT ADAPTED TO ITS ROLE?** -The disc shape increases surface area, so more oxygen can be absorbed in the lungs -There is no nucleus, which allows more space to carry oxygen **WHITE BLOOD CELLS** -White blood cells are part of the immune system -They help the body fight infection and disease **\>HOW IS IT ADAPTED TO ITS ROLE?** -White blood cells have an irregular shape so they can squeeze out of blood vessels and get to the site of infection -Some can change shape to surround and engulf pathogens **NERVE CELL** -Nerve cells transmit electrical signals in the nervous system **\>HOW IS IT ADAPTED TO ITS ROLE?** -Nerve cells are thin and very long, so they can carry messages over long distances in the body -They have branched connections allowing them to pass messages all over the body -They are surrounded by a fatty myelin sheath which increases the speed that messages can travel **BONE CELL** -help your bones grow and develop **\>HOW IS IT ADAPTED TO ITS ROLE?** -Osteoblasts form new bones and add growth to existing bone tissue. -Osteoclasts dissolve old and damaged bone tissue so it can be replaced with new, healthier cells created by osteoblasts. **CHONDROCYTES** -cells responsible for cartilage formation **\>HOW IS IT ADAPTED TO ITS ROLE?** -Chondrocytes are mainly responsible for the production of collagen and the extracellular matrix that will lead to the maintenance of cartilaginous tissues within joints. **FIBROBLAST** -a type of cell that contributes to the formation of connective tissue **\>HOW IS IT ADAPTED TO ITS ROLE?** -Fibroblasts secrete collagen proteins that help maintain the structural framework of tissues. **MUSCLE CELLS** -Muscle cells are cells which are found in bundles which make up muscles throughout the body **\>HOW IS IT ADAPTED TO ITS ROLE?** -Muscle cells are able to contract and relax -They can be found in many locations e.g. cardiac muscle in the heart, skeletal muscles which are joined to bones and smooth muscles such as the cells which line the stomach **FAT CELL** -Fat cells store energy in the form of fat **\>HOW IS IT ADAPTED TO ITS ROLE?** -Fat cells can expand to store more fat -They have few mitochondria as fat cells need very little energy -Fat acts as soft elastic padding to protect organs **CILIATED CELL** -Found in the airways to move mucus and dust out -They are also found in the oviducts to move the egg cell from the ovaries to the uterus **\>HOW IS IT ADAPTED TO ITS ROLE?** -Ciliated cells have tiny hairs on top of them called cilia which beat in a rhythm **[CELL TYPES]** -The cell is the lowest level of structure capable of performing all the activities of life. -Animals and plants are multicellular living organisms that are made up of many cells. -Cells grouped together to form tissues and fulfill similar function. **4 BASIC TYPE OF TISSUES (TISSUES IN ANIMALS)** **=1. EPITHELIAL TISSUE (TISSUES IN ANIMALS)=** -form the covering of surfaces of the body located both in internal and external parts **\>Functions:** \(1) protection of the underlying tissues, \(2) absorption, \(3) secretion, and \(4) reception of sensory stimuli. TYPES EPITHELIAL TISSUE [Based on number of cell layers] - Simple - Stratified - Pseudostratified [Based on shape of cells] - Squamous - Cuboidal - Columnar **TYPES EPITHELIAL TISSUE BASED ON SHAPE OF CELLS** **1. SQUAMOUS CELL** -thin, scaly-look like, flattened on the surface, fried-egg appearance with rounded nucleus **\>FUNCTION:** - diffusion - filtration - secretion - protection **\>LOCATION:** - kidney - air sacs - lining of heart **2. CUBOIDAL CELL** -dice shape, square-like shape with large and spherical nuclei **\>FUNCTION:** - secretion - absorption **\>LOCATION:** - kidney tubules - egg cells - ducts and secretory position of small glands. **3. COLUMNAR CELL** -taller rather than wide, column in shape, long and rectangular shape with oblong nuclei or elongated nucleus **\>FUNCTION:** - absorption - secretion - reception - sensory **\>LOCATION:** - digestive tubes - gallbladder - uterine tubes - uterus - nose, ears, tongue **TYPES COLUMNAR CELLS** **A. CILIATED COLUMNAR CELL** -fine hair-like projection **\>FUNCTION:** - move mucus and other substance across the cell, ciliary action **\>LOCATION:** - nose - uterus, fallopian tube,s, egg cells **B. PSEUDOSTRATIFIED COLUMNAR CELL** -false stratification or appearance, free surfaces with hair-like projection, nuclei seen at different level **\>FUNCTION:** - filtration - absorption - secretion - ciliary action **\>LOCATION:** - ducts of large glands - ductus difference - trachea, throat, mouth **=2. CONNECTIVE TISSUE (TISSUES IN ANIMALS)=** -use to connect, bind, hold, and support one part to another part of the body. -most vascularized and widely distributed inside the body -characterized by a large percentage of living cells and non-living material known as matrix which is made of ground substance and fibrous structures **TYPES CONNECTIVE TISSUE** **1. BONE TISSUE** **\>SPECIFIC FUNCTION** -support, protects, provides lever, storage, hematopoiesis **\>SPECIALIZED CELL** -Bone cell (osteocytes) **\>MATRIX** -hard or calcified **2. HYLAINE CARTILAGE** **\>SPECIFIC FUNCTION** -support, cushion properties **\>SPECIALIZED CELL** -chondrocytes **\>MATRIX** -firm, collagenous fibers **3. FIBRO CARTILAGE** **\>SPECIFIC FUNCTION** -absorb compressive shock **\>SPECIALIZED CELL** -chondrocytes **\>MATRIX** -collagenous fibers **4. ELASTIC CARTILAGE** **\>SPECIFIC FUNCTION** -support the external **\>SPECIALIZED CELL** -chondrocytes **\>MATRIX** -elastic fibers **5. AREOLAR CARTILAGE** **\>SPECIFIC FUNCTION** -holds and conveys tissue fluid, inflammation **\>SPECIALIZED CELL** -mast cells, white blood cells, fibroblasts, macrophages **\>MATRIX** -gel-like matrix, collagen fibers, elastic fibers **6. ADIPOSE TISSUE** **\>SPECIFIC FUNCTION** -storage of lipids for energy building **\>SPECIALIZED CELL** -fat cells, adipocytes **\>MATRIX** -reticular, collagen with collagenous fibers **7. CARTILAGE TISSUE** **\>SPECIFIC FUNCTION** -support, helps to provide structures **\>SPECIALIZED CELL** -chondrocytes **\>MATRIX** -rubbery, collagen, elastic fibrous secretion of chondroitin substance **8. AREOLAR TISSUE** **\>SPECIFIC FUNCTION** -holding the organs in a particular area **\>SPECIALIZED CELL** -fibroblasts **\>MATRIX** -collagen structure, elastic **=3. MUSCLE TISSUE (TISSUES IN ANIMALS)=** **MUSCLE TISSUE** -composed of muscle cells that are designed for contraction and movement -inside the muscle fiber or a muscle cell is consists of sarcoplasm known as the cell membrane, sarcolemma as the cytoplasm of the muscle cell and the cell body that containing nucleus located at the center **TYPES MUSCLE TISSUE** **1. STRIATED/ VOLUNTARY/ SKELETAL MUSCLE CELLS** -Long cylindrical shape, bundle forms, many nucleus, many striations **\>LOCATION** -Skeletal muscles **2. STRIATED/ INVOLUNTARY/ CARDIAC MUSCLE CELLS** -short branching shape have few striations single nucleus/two nucleus **\>LOCATION** -Heart/ cardiac muscle **3. NON-STRIATED/ INVOLUNTARY/ SMOOTH MUSCLE CELLS** -spindle in shape of cells one nucleus located at the center no striations **\>LOCATION** -visceral/ smooth muscle tissue **=4.** **NERVOUS TISSUE (TISSUES IN ANIMALS)=** **NERVOUS TISSUE** **Consists of two types of cells:** **-Conducting cells** - aka neurons are modified to respond to specific stimuli. **-Supportive cells** -- aka neuroglia; It transports nutrients from the blood vessels to neurons and guard against toxin by creating barrier to many harmful substances. **NEURONS** **Two properties of neurons:** **1. IRRITABILITY** - The ability to respond to stimuli is one of the characteristic of living things. **2. CONDUCTIVITY -** The ability to transmit an impulse **Neuron consists of two major parts:** **1. Cell body or soma** -which contains nucleus that is located at the center and its function is to control the entire activities of the neuron. **3 DISTINCT PARTS:** **Axolemma** - is known as the cell membrane **Axoplasm** - is the cytoplasm of the neuron **Neurilemma** -- the plasma membrane of the Schwann cell 2\. **Processes** that composed of collectively **nerve fibers** that also made up of the dendrites and axon. **DENDRITES -** these are the short branch located around the nucleus and conducts electrical impulses **toward the cell body.** **AXON -** contains a single long branch that is responsible of conducting impulses **away from the cell body**.