Cell Biology PDF

Cell Biology Cell Biology Cell biology also known as “cytology” is the study of cell structure and function, and it revolves around the concept that the cell is the fundamental History of Cell Biology The term “cell” was first introduced by an English...

Cell Biology Cell Biology Cell biology also known as “cytology” is the study of cell structure and function, and it revolves around the concept that the cell is the fundamental History of Cell Biology The term “cell” was first introduced by an English scientist, Robert Hooke, in 1667. He used one of the earliest microscopes to examine thin slices of cork from the bark of a tree. History of Cell Biology Hooke saw closely-packed little boxes with thick walls – “cells” just like the cells in honeycombs or prison. In fact, Hooke only saw the walls of dead plant cell. History of Cell Biology Microscope Cork cells Cells Cells are the building block of life. They are the simplest units that exhibit the characteristics of life. Cell Theory Cell Theory is one of the basic principles of biology. 3 Principles of Cell Theory 1. Cell is the basic unit of structure and organization in organisms. 2. All living organisms are composed of cells. 3. Cell arise from pre-existing cells. Cell Theory “Cell is the basic unit of structure and organization in organisms.” 2 Types of Organisms Robert Unicellular Multicellular Hooke Cell Theory “All living organisms are composed Theodor of cells.” Matthias Schwann Schleiden All animals are All plants are made made up of cells. of cells. Cell Theory “Cell arise from pre-existing cells.” Rudolf Virchow Parts of the Cell Cell is the basic unit of life. Protoplasm – “proto” means first, “plasm” means form. The protoplasm of a cell is made up of three parts: 1. Cell membrane 2. Nucleus 3. Cytoplasm Cell Membrane Cell membrance is a.k.a. plasma membrane. It surrounds the cytoplasm of the cell. It is semi-permeable: allows only some substances to pass through it. Hence, it controls substances entering or leaving cell. Cell Membrane Cell membrane = “gatekeeper of the cell” Cell Membrane According to Singer & Nicolson, Cell membrane is described as “fluid mosaic”. Nucleus Nucleus is a.k.a the “control center of the cell.” It controls cell activities such as cell growth andDNA. It contains the repair of worn-out parts and cell division. It is surrounded by double-layer membrane. Parts of the Nucleus Nuclear envelope It is a double-layer membrane which separates the contents of the nucleus from the rest of the cytoplasm. Parts of the Nucleus Nucleoplasm It is the dense material within the nucleus. Parts of the Nucleus Nucleolus It is the largest structure in the nucleus of eukaryotic cells. It is best known as the site of ribosome Parts of the Nucleus Chromatin It is a complex of DNA and proteins called “histones” that forms chromosomes within the nucleus of eukaryotic cells. Parts of the Nucleus Nuclear pore It is the channel in the nuclear envelope that regulates the transport of molecules between Cytoplasm Cytoplasm is the part of the protoplasm between the cell surface membrane and the nucleus. Cytoplasm is the combination of jelly-like substance called Organelles 1. Cell wall These parts are 2. Endoplasmic embedded within Reticulum the cytoplasm. 3. Mitochondrion Organelles are 4. Vacuole 5. Lysosomes often enclosed 6. Peroxisomes by their own 7. Chloroplast membrane. 8. Golgi apparatus 9. Centrioles Cell Wall Cell wall is a rigid organelle. It provides support, protection and shape of the cell. It is present ONLY in: 1. Plants 2. Fungi 3. Bacteria Cell Wall Structure Type Plant Fungi Bacteria Componen Cellulose Chitin Peptidoglyc t an Endoplasmic Reticulum (ER) ER is also known as “highway system” of the cell. It is a network of membranous tubules within the cytoplasm, continuous with the Endoplasmic Reticulum (ER) Rough ER Nucleus Rough ER is called rough becau se it has ribosomes attached to its surface. Funtion: Protein Synthesis Endoplasmic Reticulum (ER) Smooth ER Nucleus Smooth ER is not associated with ribosomes. Funtion: Lipid Synthesis Mitochondrion Mitochondrion is a.ka. “powerhouse” of the cell. Mitochondria are sausage-shape organelles that is considered the power generators of the cell, converting oxygen and nutrients into adenosine triphosphate (ATP). ATP is the energy of the cell. Parts of Mitochondrion Cristae Outer It is the infolding Membrane Inner of the inner Membrane membrane. Matrix It is the liquid inside the mitochondrion. Vacuoles Vacuole is a.ka. “storage tank” of the It cell. is a space within a cell that is empty of cytoplasm, lined with a membrane, and filled with fluid. Function: storage of food, water and wastes. Vacuoles Animal Cell Plant Cell Vacuole Lysosomes Lysosome is a.ka. “suicide bags” of theorganelle An cell. in the cytoplasm of the cells containing hydrolytic enzymes enclosed in a membrane. Function: 1.used to digest food and protection. 2.break down the cell when it dies. Lysosomes Animal Cell Plant Cell Lysosom e Lysosomes for Protection Lysosome Bacterium Lysosomes for Cell Suicide Apoptosis is the death of cells that occurs as a normal and controlled part of an organism's growth or development. Peroxisomes It is small organelle that is present in the cytoplasm of many cell that contains enzymes. Functions: 1. absorb nutrients that the cell has acquired. 2. play a part in the way organisms digest alcohol (ethanol). Peroxisomes Chloroplast Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide gas to produce food for the plant. Parts of Chloroplast Inner Outer Membrane Membrane Granu m Stroma Thylakoid Golgi Apparatus It is the “post office” of the cell. It is a complex of vesicles and folded membranes within the cytoplasm of most cells,. Function: 1. waste secretion Golgi Apparatus Centrioles These are minute cylindrical organelles near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell Centrioles in Sperm Cell Sperm Cell Ribosome Ribosome is NOT considered as an organelle because it lacks membrane covering. It is a complex molecular machine, found within all living cells, that serves as the site of protein synthesis. Ribosome Ribosomes can be found in ALL types of cells. It can be located in: 1. Cytoplasm 2. Rough ER Cytoskeleton Cytoskeleton is also known as “framework” of the cell. These structures give the cell shape and help organize the It is cell's parts. in also present ALL types of cell. Cytoskelet on  3 Components of Cytoskeleton Microfilament Microtubule Intermediate Filament How do cells move around? White blood cell Actual footage of chasing a swimming sperm bacterium. cells. How do cells move around? Movements of Amoeba paramecium Cell Motility Cell Motility is required for many important physiological processes during cell development, such as cell migration and cell regeneration. 3 Locomotive Structures of Cell 1.Cilia 2.Flagella 3.Pseudopodia Cilia Cilia is hair-like filament that is numerous on tissue cells of most animals and provides the means for locomotion of protozoans and Cilia Flagella Flagellum is a whip-like structure that allows a cell to move. Euglena Sperm cells  4 Types of Flagellar Arrangement Peritrichous Monotricho AmphitrichouLopotrichous us s Pseudopodia “Pseudo” means false and “Podia” means “foot”. It is cytoplasm-filled projection of an eukaryotic cell membrane or a unicellular protist. Function: Amoeba Movement and  2 Classifications of Cells Eukaryotic Prokaryotic “Eu” means true “Pro” means before and “karyo” and “karyo” means means nucleus. nucleus. This is a type of This is a type of cell cell with true without nucleus. nucleus.  Difference of Eukaryotes and Prokaryotes Eukaryotic Prokaryotic SIZE: SIZE: Larger than 10 Smaller than 10 micrometres. micrometres.  Difference of Eukaryotes and Prokaryotes Eukaryotic Prokaryotic DNA: DNA: DNA is linear and DNA in a ring form enclosed within a and free in nucleus. cytoplasm.  Difference of Eukaryotes and Prokaryotes Eukaryotic Prokaryotic Organelles: Organelles: With organelles Without organelles  Difference of Eukaryotes and Prokaryotes Eukaryotic Prokaryotic Cell wall: Cell wall: Cell wall is made Cell wall is made up of cellulose or up of chitin. peptidoglycan.  Similarities of Eukaryotes and Prokaryotes Eukaryotic Prokaryotic They both have: Ribosomes Cell membrane DNA Cytoskeleton Cell wall (different composition)  Comparative Cell Biology Animal Cell Plant Cell  Similarities of Animal and Plant Cells Animal Plant They are both eukaryotic cell. They both have: Cell membraneGolgi Cytoplasm Nucleus apparatus Rough ER DNA Mitochondrion Smooth ER Cytoskeleton Lysosomes Peroxisomes Ribosomes Difference of Animal and Plant Cells Animal Plant Size: Size: Smaller Larger Difference of Animal and Plant Cells Animal Plant Shape: Shape: Do not have Have a fixed definite shape. shape. Difference of Animal and Plant Cells Animal Plant Cell wall: Cell wall: Absent Present  Difference of Animal and Plant Cells Animal Plant Vacuole: Vacuole: Usually absent. If Have a large present, vacuoles central vacuole. are small. Difference of Animal and Plant Cells Animal Plant Chloroplast: Chloroplast: Absent Present in green plants. Difference of Animal and Plant Cells Animal Plant Centrioles: Centrioles: Present Absent Difference of Animal and Plant Cells Animal Plant Food storage: Food storage: Glycogen Starch Review of Animal Cell Cell membrane Mitochondrion Lysosomes Golgi Apparatus Vesicles Review of Animal Cell Vacuole Centrioles Nucleus Rough ER Cytoplasm Review of Animal Cell Smooth ER Nuclear envelope Nuclear pore Nucleolus Nucleoplasm Review of Plant Cell Cell Wall Cell membrane Chloroplast Vacuole Lysosome Review of Plant Cell Mitochondrion Cytoplasm Rough ER Smooth ER Golgi Apparatus - THANK YOU! -