Biology PDF - Cell Theory & Classification

3 DOMAIN CLASSIFICATION SCHEME - Living things can be grouped in 3 IV. LIFE GROWS, DEVELOPS, domains. AND REPRODUCES ITSELF - The domains Bacteria and Archaea - Living things make other individuals were separated because the archaeans are...

3 DOMAIN CLASSIFICATION SCHEME - Living things can be grouped in 3 IV. LIFE GROWS, DEVELOPS, domains. AND REPRODUCES ITSELF - The domains Bacteria and Archaea - Living things make other individuals were separated because the archaeans are that are similar to themselves. In order to do more closely related to eukaryotes than to this, they must grow and develop to bacteria. adulthood. ✇ BACTERIA V. LIFE EVOLVES - These are also known as eubacteria or - Living things change overtime in true bacteria. order for them to be better suited to the - Bacteria are prokaryotic cells. ever-changing environment. ✇ THE ARCHAEANS CELL THEORY - These are also known as Robert Hooke archaebacteria. - discovered cells on cork from oak - They are believed to be the first living - coined the term “cell”. things. - Archaeans mean ancient bacteria. Anton Von Leeuwenhoek - called protozoans as “animalcules” ✇ EUKARYA - These are also known as eukaryotes. Matthias Schleiden - These have eukaryotic cells. - German botanist - concluded that “all plants have cells” CHARACTERISTICS OF LIFE I. LIFE IS ORGANIZED Theodor Schwann - Living things are made up of parts or - German zoologist structures that are arranged in a - concluded that “all animals have cells” hierarchical pattern. Rudolf Virchow II. LIFE REQUIRES ENERGY - studied cell cultures - Living things acquire and use energy - discovered that cells divide and nutrients to fuel the different processes that sustain life. Robert Brown - discovered the nucleus - concluded that the nucleus is important III. LIFE MAINTAINS INTERNAL and is abasic part of the cell BALANCE - Living things maintain internal Felix Dujardin conditions within a constant range, - studied the “fluid” inside the cell and even if the external environment called it “sarcode” (which is actually the changes. protoplasm)  Rough ER Rene Dutrochet - located close to the nucleus - one of the first scientists to come up with - occurs as a flattened structure the idea that “the cells are the basic units - synthesizes housekeeping proteins and of life” secretory proteins Smooth ER Louis Pasteur - has no ribosomes attached to it - supported the idea that all cells come - synthesizes lipids from pre-existing cells - contains enzymes that detoxify drugs and poisons 3 POSTULATES - forms vesicles for transporting large molecules to other parts of the cell - All living things are composed of one or more cells. GOLGI APPARATUS - The cell is the basic unit of life. - stack of flattened membranous sacs - All new cells arise from pre-existing cells. where proteins from the ER complete their intricate folding and become PARTS OF EUKARYOTIC CELL functional CELL MEMBRANE - contains enzymes that manufacture and - separates the cytoplasm from the cell’s attach carbohydrates to proteins and external environment lipids, forming “name tags” recognized by - responsible for transporting substances the immune system into and out of the cell - Post office of the cell - Gatekeeper of the cell LYSOSOME CYTOPLASM - contains hydrolytic enzymes - where many of the cell’s metabolic (originating in the RER) that reactions occur breakdown and recycle food particles, - where organelles, inclusions, and captured bacteria, worn out organelles and cytoskeletal filaments are embedded debris - plays an important role in apoptosis NUCLEUS (programmed cell death) - controls the functions of entire cell - Recycling center - composed of the nuclear membrane, the nucleoplasm, the chromosomes, and the PEROXISOME (Microbody) nucleolus - contains several types of enzymes that - Control center dispose of toxic substances - breaks down fatty acids and produces ENDOPLASMIC RETICULUM cholesterol and some other lipids - highly coiled and folded system of membranes that are interconnected and 📬 Vacuoles in Protists VACUOLE arranged to form a transport network - Highway of the cell - In paramecia, contractile vacuoles pump out excess water from the cell. - In amoeba, food vacuoles digest - Protein factories nutrients that the cell has engulfed through - composed of two subunits: phagocytosis. Alpha subunit – large subunit (60s) Beta subunit – small subunit (40s) 📬 Animal Vacuoles - maybe bound or free: Bound Ribosome: attached to the RER; - may store water or food make both secretory and - excrete waste materials through housekeeping proteins 📬 exocytosis Free Ribosome: suspended in Plant Vacuoles the cytosol; makes housekeeping - contain an aqueous solution of proteins enzymes that degrade and recycle molecules and organelles - remain separated unless they will make proteins; will separate again after MITOCHONDRION making proteins - site of cellular respiration - semi-autonomous CYTOSKELETON - responsible for producing energy in the - intricate network of protein “tracks” and form of ATP through cellular respiration. tubules that serve as the structural - Powerhouse of the cell framework of a eukaryotic cell - serves as a transportation system within the cell Basic Structure - provides structural support and helps Cristae – folds of inner membrane; add with cell movement and division. tremendous surface to the inner membrane, - Cellular skeleton which contains the enzymes that catalyze cellular respiration Three Major Components Matrix – inner cavity into which the cristae Microfilaments project; filled with semi fluid medium - also called actin filaments containing enzymes that break down - thinnest components (with a diameter of carbohydrate products 7nm) - provide strength to cells to survive Mitochondrial DNA – encodes proteins stretching and compression essential for mitochondrial structure and - help anchor one cell to another function; useful for tracking inheritance through female lines in a family Intermediate Filaments - have diameters that are between those RIBOSOME of microfilaments and microtubules - site of protein synthesis: receives (10nm) coded message from DNA (through - maintains cell’s shape by forming a mRNA) as to the kind of protein to be scaffold in the cytosol and resisting manufactured mechanical stress - help bind some cells together - produces food through photosynthesis in plant cells Microtubules - responsible for photosynthesis in plant - hollow tubes that are about 23nm in cells and some other organisms. diameter; composed of tubulin dimers - Solar panels - form a type of “trackway” along which substances move within the cell Tissue - splits a cell’s chromosomes during cell - A group of cells that function division together to perform their job in specific body parts CENTROSOME & CENTRIOLES Four Types of Animal Tissues Centrosome - spherical structure located just outside Connective and Supportive Tissues - the nucleus responsible for the connecting and - found in animal cells only supporting body parts - organizes the spindle apparatus (a set of microtubules that coordinate the Epithelial Tissues- responsible for movements of chromosomes during cell protecting our body division) - contains two centrioles Muscular Tissues - allow the movement of the body Centrioles - cylindrical structures that lie close Nervous Tissues – control and together at the center of the coordinate the functions of body parts centrosome - oriented at right angles to each other Three Types of Epithelial Tissues: - lacking in most cells of higher plants - associated with spindle formation (as Squamous Epithelium - for selective they also produce microtubules) transport of substances; found in inner - indirectly produce cilia and flagella surface of lungs, blood-vessels, and - has atriplets of microtubules held alveoli together by supporting proteins Cuboidal Epithelium - for CILLIUM & FLAGELLUM reabsorption of useful substances from - for locomotion urine; found in tubules of the kidney - contain an internal 9+2 arrangement of microtubules: 9 outer doublet Columnar Epithelium – for secretion of microtubules surrounding a central pair of digestive juices; found in inner single microtubules. surface of intestine, stomach, and colon Three Types of Muscular or Contractile CHLOROPLAST (Plastid) Tissues:  Skeletal Muscle - produces movement for the bones Cardiac Muscle - responsible for involuntary contractions of heart Visceral or Smooth Muscle - responsible for involuntary movements of internal organs Five types of Connective and Supportive Tissues: Vascular tissue (Blood) - responsible for transportation of nutrients and wastes; found in bloodvessels Bone - responsible for movement, support and protection of different organs; found throughout the body Cartilage - uses flexibility to protect bones and joints; found where two bones meet in the body Fibrous Tissue - holds bones, muscles, tissues, and organs in place; found in ligaments and inner layers of skin Adipose Tissue – insulates body parts and protects these from mechanical injury