Cell Theory Notes PDF

‘bios’ ‘logos’ (life) (study) “the study of life” “the study of organisms and their interactions with one another and their environments” SHORT REVIEW  Levels of BIOLOGICAL ORGANIZATION  LEVELS OF BIOLOGICAL...

‘bios’ ‘logos’ (life) (study) “the study of life” “the study of organisms and their interactions with one another and their environments” SHORT REVIEW  Levels of BIOLOGICAL ORGANIZATION  LEVELS OF BIOLOGICAL ORGANIZATION  1.) Atoms – basic unit of matter. They bond with each other to form molecules.  2.) Molecules – Groups of atoms; smallest unit of most chemical compounds. Molecules form the cells.  3.) Cells – smallest unit of a living thing. Groups of cells form tissues.  4.) Tissues – A group of cells with a common structure and function. Groups of tissues form organs.  5.) Organs – Composed of a number of tissues and organized for a particular task.  6.) Organ System – groups of organs that work together to perform a certain function in an organism’s body.  7.) Organism/Individual – Individual living thing; Contains organ systems.  8.) Population – several organisms of the same kind (same species) in a particular area & a certain period of time.  9.) Community – Interacting populations in a defined area.  10.) Ecosystem – Community and its non-living surroundings.  11.) Biosphere – Region of the Earth’s crust, waters and atmosphere inhabited by living things. Lesson 1 Cell theory -one of the main principles in Biology. -explains the nature of the cell. -composed of 3 statements/postulates. Postulate #1 ALL LIVING THINGS ARE COMPOSED OF ONE OR MORE CELLS. Postulate #2 THE CELL IS THE BASIC UNIT OF LIFE. Postulate #3 ALL CELLS COME FROM PRE-EXISTING CELLS. States that… 1.) ALL LIVING THINGS ARE COMPOSED OF ONE OR MORE CELLS. 2.) THE CELL IS THE BASIC UNIT OF LIFE. 3.) ALL CELLS COME FROM PRE-EXISTING CELLS. The discovery of cells paved way to the formation of the cell theory The scientific history that lead to the CELL THEORY. 1595 Zacharias janssen Credited for the invention of the first compound microscope. 4 My work Janssen’s compound microscope Describe the -has two glass lenses located at each end of a section briefly hollow tube. REVIEW: Microscope An instrument used for viewing very small objects. Enlarges/magnifies the image of the actual object 1595 Zacharias janssen Credited for the invention of the first compound microscope. 4 My work Janssen’s compound microscope Describe the -has two glass lenses located at each end of a section briefly hollow tube. 1665 Robert hooke Used an early compound microscope of his own design 4 to look at thin slices of cork My work tissue. Describe the section briefly 1665 Robert hooke He observed that the cork is 4 made up of tiny empty boxes like the tiny rooms in a monastery. My work Describe the section briefly 1665 Robert hooke He called them cell. 4 My work Derived from the Latin word Describe the CELLULA meaning “small section briefly compartment”. 1665 Robert hooke Thus, he was the first to discover the cells. 4 My work Cork cells are dead cells Describe the section briefly thus he was the first to discover dead cells. 1674 Anton van leeuwenhoek An enthusiast of observing 4 things under My work his self-made Describe the section briefly single-lens microscope. 1674 Anton van leeuwenhoek He obtained samples from 4 almost anywhere that he My work could think of such as pond Describe the water and scrapings from section briefly his teeth and gums. 1674 Anton van leeuwenhoek From his observations, he 4 was able to witness various My work tiny living things which he Describe the termed as animalcules. section briefly Leeuwenhoek found motile objects. He stated that motility is a quality of life therefore these were living organisms. Leeuwenhoek named these “animalcules,” which included protozoa and other unicellular organisms, like bacteria. 1674 Anton van leeuwenhoek 4 He is commonly known as the My work “Father of Microbiology”. Describe the section briefly 1831 Robert brown Discovered a central structure 4 in orchid leaf This My work cells. structure is Describe the now called section briefly the nucleus. 183os Matthias schleiden A botanist. 4 He observed My work various plant He came to the tissues. conclusion that Describe the section briefly plants are made of cells. 183os Theodor schwann A zoologist. 4 He came to the He observed My work conclusion that various animal Describe the animals are made tissues. section briefly of cells. 1855 Rudolf virchow A physician and pathologist. 4 Virchow theorized that as animals are unable to My work arise without previously existing animals, cells Describe the are unable to arise without previously existing section briefly cells.  The discoveries made by Hooke, Leeuwenhoek, Schleiden, Schwann, Virchow, and others led to the formulation of the cell theory. 1.) ALL LIVING THINGS ARE COMPOSED OF ONE OR MORE CELLS. 2.) THE CELL IS THE BASIC UNIT OF LIFE. 3.) ALL CELLS COME FROM PRE-EXISTING CELLS.  Lesson 2 Cell structures & function  Cell Theory Postulate # 2 Cell is the basic unit of life  Cell Theory Postulate # 2 Cell is the basic unit of life The cell is composed of parts/structures with corresponding functions. The cell is like a factory  Cell Theory Postulate # 2 Cell is the basic unit of life The cell is composed of parts/structures with corresponding functions. Without these functions, the cell will die…. ….and the organism as a whole will die too. There are 2 main types of cells: Prokaryotic VS. Eukaryotic cell cell Eukaryotic Cells has 2 types: animal cell animal cell plant cell animal cell Eukaryotic Cells are made up structures called “organelles” (tiny organs)  Cell membrane/ plasma membrane *found in animal & plant cells composed of the lipid bilayer (two layers of lipid membrane). Separates the internal and external environment of the cell. Regulate passage of materials in and out of the cell.  Cytoplasm *found in animal & plant cells Entire space/region inside the cell. Filled with fluid called cytosol Holds organelles in place and other cell structures. Site for chemical reactions.  ribosomes *found in animal & plant cells Found scattered in the cytoplasm (free ribosomes) & those attached in the Endoplasmic Reticulum (attached ribosomes). Makes or synthesizes proteins. SHORT REVIEW 4 Main Types of Biological Macromolecules Biological macromolecules 1. CARBOHYDRATES 2. PROTEINS 3. LIPIDS 4. NUCLEIC ACIDS  nucleus *found in animal & plant cells Prominent in the eukaryotic cell. Contains the genetic material (DNA or Deoxyribonucleic acid). Note: DNA in the nucleus are arranged in structures called chromatin and chromosomes. controls the cell’s activities specifically the synthesis of ribosomes and proteins.  nucleus *found in animal & plant cells -nucleolus contains genetic materials and also the site of making ribosomal sub-units.  mitochondria (sing. ‘mitochondrion’) *found in animal & plant cells rod-shaped, double membrane-bound organelle (having an outer membrane and folded inner membrane called cristae). the “powerhouse of the cell” because it is responsible for the supply and storage of energy in the form of ATP (Adenosine triphosphate).  peroxisomes *found in animal & plant cells Small, round organelles that carry out oxidation reactions that break down fatty acids and amino acids. Detoxify many poisons that may enter the body.  peroxisomes *found in animal & plant cells Detoxify many poisons that may enter the body. Many oxidation reactions release hydrogen peroxide, H2O2, which would be damaging to cells; however, when these reactions are confined to peroxisomes, enzymes safely break down H2O2 into oxygen and water. For example, alcohol is detoxified by peroxisomes in liver cells.  centrosomes *found in animal cells Composed of pair of small cylindrical structures called centrioles (long, stiff fibers).  centrosomes *found in animal cells These organelles are only active during cell division (when a cell replicate themselves). They release long, stiff fibers and anchor them to chromosomes (in order to split the chromosomes apart) during cell division.  lysosomes *found in animal cells Spherical sacs that contain digestive enzymes. These enzymes breakdown macromolecules (carbohydrates, lipids, proteins, and nucleic acids) Also destroy pathogens (e.g. bacteria and virus) that might enter the cell. Also, break down excess or worn-out cell parts.  Cell wall *found in plant cells a rigid layer that surrounds the cell membrane of plant cells. protects the cell, provides structural support, and gives shape to the cell. Cell Cell membrane wall chloroplast *found in plant cells double-membraned organelle with stacks of disk-shaped structures called thylakoids.  chloroplast *found in plant cells This organelle carries out photosynthesis for both plants and algae. It contains the pigment chlorophyll that is responsible for capturing light energy to drive the reactions of photosynthesis. Vesicles/vacuoles *found in animal & plant cells Membrane-enclosed sacs that functions in storage and transport of materials. Vesicles/vacuoles *found in animal & plant cells Difference between vesicles and vacuoles. Vesicles – smaller in size; can fuse with either the plasma membrane or other membrane systems (Golgi Apparatus, Endoplasmic Reticulum) within the cell. For storage and transport of materials. Vesicles/vacuoles *found in animal & plant cells Difference between vesicles and vacuoles. Vacuoles – larger in size; do not fuse with membranes and other cellular components. For storage only Vesicles/vacuoles Example of Vacuole: Central Vacuole Largest organelle in plant cells. Filled with fluid called cell sap. Functions in storage, breakdown of waste products and macromolecules. also applies pressure to the cell wall causing the plant to stand upright. *found in plant cells Vesicles/vacuoles Example of Vacuole: Central Vacuole also applies pressure to the cell wall causing the plant to stand upright. *found in plant cells Endoplasmic reticulum (ER) *found in animal & plant cells Structures found near the nucleus which are made up of a number of flattened sacs called cisternae, which are continuous with the nuclear envelope. Endoplasmic reticulum *found in animal & plant cells It has TWO Types: Rough Endoplasmic Reticulum Smooth Endoplasmic Reticulum Endoplasmic reticulum (Rough E.R.) *found in animal & plant cells Attached with Ribosomes. Transports proteins made in the Ribosomes. Endoplasmic reticulum (Smooth E.R.) *found in animal & plant cells Absence of ribosomes on its surface. Makes lipids.  Golgi apparatus/ golgi complex *found in animal & plant cells Stacks of flattened membranous sacs located next to endoplasmic reticulum. responsible for sorting, tagging, packaging, and distribution of lipids and proteins coming from the Endoplasmic Reticulum.  cytoskeleton *found in animal & plant cells network of protein fibers within the cytoplasm. maintains cell’s shape, secures organelles in specific positions, allows cytoplasm and vesicles to move within the cell, and enables cellular organisms to move independently.  cytoskeleton *found in animal & plant cells Composed of 3 types of molecular fibers: ○ Microfilaments ○ Microtubules ○ Intermediate filaments *found in animal & plant cells Has 3 types: ○ Microfilaments ○ Microtubules ○ Intermediate filaments  flagella (singular. ‘flagellum’) Aid in cellular movement. Moves in snake-like/undulating motion. Example: Sperm cell.  cilia (singular. ‘cilium’) Aid in cellular movement. Much shorter than flagella Also, it helps movement of particles. It can also act as filter. Moves in back-and-forth motion. Example: in the respiratory tract Thank you!