Anatomy and Physiology of Cells - PDF

 Anatomy and Physiology INTRODUCTION - Study of anatomy and physiology is an ever developing science. - Greek and Latin form the basis for the language of anatomy and physiology. DEFINITIONS: A. ANATOMY = the study of the structure (morphology, form) of...

 Anatomy and Physiology INTRODUCTION - Study of anatomy and physiology is an ever developing science. - Greek and Latin form the basis for the language of anatomy and physiology. DEFINITIONS: A. ANATOMY = the study of the structure (morphology, form) of body parts. B. PHYSIOLOGY = the study of the function of body parts.  ANATOMY (STRUCTURE) DICTATES FUNCTION Function: The human hand has many functions, but we’ll focus just on two: grasping things for fine control (such as a rock), and grabbing objects for power (as in the example of the wooden stick above). Structure to function relationship: the opposable thumb (the ability to touch the thumb to the fingers) makes fine control possible. The ability to touch the fingers to the base of the hand and to wrap the thumb on top makes the power grip possible. STRUCTURAL LEVELS OF ORGANIZATION: A. The atom [i.e. Carbon (C), Hydrogen (H), or Oxygen(O)] is the least complex level. An atom is defined as the smallest particle of an element. Atoms combine with (react with) other atoms to form... B. molecules [i.e. carbon dioxide (CO2), water (H20)]. A molecule is defined as a particle composed of 2 or more joined atoms. Molecules combine with other molecules to form... C. macromolecules (i.e. carbohydrates, lipids, proteins, nucleic acids). A macromolecule is defined as a large molecule. Macromolecules combine with other macromolecules to form... D. organelles (i.e. cell membrane, nucleus, ribosomes). An organelle is defined as a small organ of a cell, which performs a particular function. Organelles collectively compose...  Levels of Organization E. cells The cell is defined as the basic unit of structure and function of living organisms! Each cell has a set of organelles and performs a particular function (i.e. a red blood cell has a biconcave shape and is a nucleate. This structure increases its surface area, allowing for the transport of more oxygen). Some cells have all of the machinery that they need to live. Similar cells are arranged into... F. tissues (i.e. epithelia, connective, muscle, nervous). A tissue is defined as a group of similar cells that performs a specialized function. Two or more tissues combine to form...  Levels of Organization G. organs (i.e. skin, heart, brain). An organ is defined as a structure consisting of a group of tissues that performs a specialized function. Two or more organs combine to form... H. organ systems (i.e. integumentary, cardiovascular). An organ system is defined as a group of organs that act together to carry on a specialized function. There are 11 organ systems. The eleven organ systems collectively form the... I. human organism An organism is the most complex level of organization and is defined as an individual living thing. J. The levels of hierarchy could be further extended to include; populations, communities, ecosystems, and the biosphere. What do these organisms have in common? COMPOSED OF CELLS! WE ARE CELLS You, me, your family, your friends, your pet, and your mom’s precious plants each of us are made of CELLS. For humans approx. 36 trillion cells. Cells are Us There are about 200 different cell types in mammals (one of us). Cells are tiny, measuring on average about 0.002 cm Red and (20 um) across. That’s white blood cells above about 1250 cells, vessel- “shoulder-to-shoulder” per forming cells. inch. nerve cell THE CELL Anatomy & Physiology Christine Mae B. Tecson  01 02 History of the cell What is a cell? 03 04 Cell structure & function Microscopy  SECTION 1 HISTORY OF THE CELL WATCH THIS!  THE CELL THEORY 1. ALL ORGANISMS ARE MADE OF ONE OR MORE CELLS  THE CELL THEORY 2. THE CELL IS THE BASIC UNIT OF STRUCTURE AND ORGANIZATION IN ORGANISMS  THE CELL THEORY 3. ALL CELLS COME FROM PRE-EXISTING CELLS "Omne vivum ex vivo" ("All life comes from life"). Spontaneous Generation: Before microscopes were invented people generally believed that life sprang from inanimate matter - that life could spontaneously be generated from inanimate matter. Robert Hooke (1665) English Scientist o Used the compound microscope to observe cork.  HOOKE’S OBSERVATIONS Hooke observed that cork is composed of small, hollow compartments. Hooke’s observation  HOOKE’S OBSERVATIONS The parts prompted Hooke to think of small rooms (cells) in a monastery, so he gave them the same name: CELLS. ANTON VAN LEEUWENHOEK (1675) Dutch Tradesman Study new approaches for creating lenses to observe cloth. Leeuwenhoek’s microscope was more powerful than Hooke’s compound microscope. Leeuwenhoek’s Microscope Leeuwenhoek’s Observations From investigating and experimenting with his microscope, Leeuwenhoek became one of the first scientists to refer to living cells when he observed an abundant number of single- celled organisms, which he called animalcules (looked like little animals) swimming in a drop of pond water! Matthias Schleiden (1838) German Scientist o Fascinated with plant cells, Schleiden used the compound microscope and studied plant cells. o From investigating and experimenting with plants, projected plant parts are made of cells! o Discussed what he observed with his dear friend, German scientist Theodor Schwann. Theodor Schwann (1839) German Scientist o Studied plant & animal cells, and was intrigued by the similarities between the two. o From investigating and experimenting with plant & animal cells, Schwann was able to determine that all animals are made of cells! o Schwann published the 1st statement of the cell theory: all living things are made of cells and cell products! Rudolf Virchow (1855) o Based on his investigations and experiments, he stated that all cells come from preexisting cells, which is the 2nd part of the cell theory: all existing cells are produced by other living cells!  IN SUMMARY There are 3 major parts of the cell theory: 1. All organisms are made of one or more cells. 2. The cell is the most basic unit of life. 3. All existing cells comes from pre-existing cells  IN SUMMARY 5 Contributors Robert Hooke Anton Van Leeuwenhoek Matthias Theodor Rudolf Virchow came up with the referred to living cells called stated all cells come from Schleiden Schwann preexisting cells (2nd name cells animalcules after observing a determined all animals drop of pond water projected plants are statement of the cell theory) are made of cells (1st made of cells statement of the cell theory)  SECTION 2 WHAT IS A CELL? What is a cell? In the hierarchy of BIOLOGICAL ORGANIZATION, the cell is the simplest collection of matter that can be alive. Cells are basic units of organisms Cells are usually observed under a microscope  Organism: Ring-tailed lemur Spinal cord Organ system: Brain Even when cells are Nervous system arranged into higher levels of organization, such as tissues and Organ: Brain organs, the cell is the Nerve basic unit of life because it is the smallest structure that can Tissue: perform all the Nervous tissue necessary activities of Atom life and is the foundation from which more complex Nucleus Cell: structures are built. Nerve cell Organelle: Nucleus Molecule: DNA  Basic cell types Animal Cell Plant Cell Bacterial Cell (EUKARYOTIC) (EUKARYOTIC) (PROKARYOTIC) 34 Cells May be Prokaryotic or Eukaryotic ▪ Prokaryotes include bacteria & lack a nucleus or membrane-bound structures called organelles ▪Eukaryotes include most other cells & have a nucleus and membrane-bound organelles (plants, fungi, & animals) PROKARYOTIC CELLS ▪ Prokaryotic means “before nucleus” (from the Greek word pro, before) reflecting the fact that it evolved before eukaryotic cells ▪The DNA in this type of cell concentrated in region that is not membraned-enclosed called nucleoid  PROKARYOTIC CELLS ▪The DNA in this type of cell concentrated in region that is not membraned-enclosed called nucleoid This colorized TEM shows a thin lengthwise slice through an Escherichia coli bacterium. Note the prominent nuclear area containing the genetic material (DNA). E. coli is a normal inhabitant of the human intestine, but under certain conditions some strains can cause infections. PROKARYOTES  EUKARYOTIC CELLS ▪ Eukaryotic means “true nucleus” (from the Greek word eu, true, and karyon, kernel, here referring to the nucleus) ▪Most of the DNA is in an organelle called the nucleus, bounded by a double membrane Eukaryotic cells descended from prokaryotic cells eukaryotes first appear in the fossil record about 2 bya, long after prokaryotic cells DNA sequencing provides evidence of common ancestry of all life on Earth, with eukaryotes splitting from Archaea about 2 bya endosymbiotic theory – model for how at least some of the eukaryotic cell organelles came to exist TWO MAIN TYPES OF EUKARYOTIC CELLS ANIMAL CELL PLANT CELL Composite diagram of a plant cell Composite diagram of an animal cell 44 copyright cmassengale Number of Cells Organisms may be: Unicellular – composed of one cell Escherichia coli Multicellular- composed of many cells that may organize Homo sapiens DIFFERENT TYPES OF EUKARYOTIC CELL  SECTION 3 CELL STRUCTURE & FUNCTION Cellular Anatomy & Physiology CLOSER LOOK AT ANIMAL CELLS: ITS ORGANELLES ANIMAL CELL Organelle a specialized cellular part that has specific function and is considered analogous to an organ. Can only be observed under a microscope 1. PLASMA MEMBRANE Controls the movement of materials into and out of the cell Selectively permeable allows passage of enough oxygen, nutrients, and wastes to service the entire cell. 1. PLASMA MEMBRANE/CELL MEMBRANE Consists of bilayer of phospholipids with various proteins embedded 2. NUCLEUS: Information central contains most of the genes in the eukaryotic cell. Nuclear envelope – double membrane enclosing the nucleus Nucleolus – non- membranous structure involved in production of ribosomes Chromatin – material consisting of DNA and proteins  Nucleus: Key Player in Protein Synthesis Protein Synthesis is one of the most important functions taking place in cells. 3. RIBOSOMES: Protein Factories Complexes made of ribosomal RNA and protein that carry out protein synthesis. From gene to one Polypeptide 4. ENDOPLASMIC RETICULUM (Biosynthetic Factory) Structure: A membranous system of interconnected tubules and flattened sacs called cisternae. It is also continuous with the nuclear envelope. Function: An essential organelle in eukaryotic cells that plays a key role in the synthesis, folding, modification, and transport of proteins and lipids. Two types: 1. Rough Endoplasmic Reticulum 2. Smooth Endoplasmic Reticulum  Rough Endoplasmic Reticulum (RER) Structure: Studded on its outer surface (the surface in contact with the cytosol) with ribosomes Functions: Protein synthesis (about half the cell’s proteins are made here) Cells specializing in the production of proteins will tend to have a larger amount of rough ER. Makes secretory proteins Ex. Pancreatic cells synthesizing the protein insulin in the ER secrete this hormone into the bloodstream. Membrane factory for the cell - it grows in place by adding membrane proteins and phospholipids to its own membrane  Rough Endoplasmic Reticulum (RER) Functions: It is in the rough ER for example that four polypeptide chains are brought together to form hemoglobin. The ER membrane expands and portions of it are transferred in the form of transport vesicles to other components of the endomembrane system Smooth Endoplasmic Reticulum (SER) Structure: outer surface lacks ribosomes Function: diverse metabolic processes, which vary with cell type. Produce sex hormones of vertebrates and steroid hormones secreted by the adrenal glands (cells that synthesize and secrete these hormones are rich in smooth ER) Other enzymes of the SER help detoxify drugs and poisons, esp. in liver cells. Cells producing lipids (fats) and steroid hormones will have a greater amount of smooth ER.  5. GOLGI BODIES (shipping and receiving center) Structure: stacked flat sacs (cisternae) looking like a stack of pita bread Function: receives proteins from the rER and distributes them to other organelles or out of the cell (receiving, processing, packaging, and shipping) Has a structural and functional directionality, with a cis face that receives vesicles containing ER products and the trans face dispatches vesicles (contains proteins or enzymes) 5. GOLGI BODIES (shipping and receiving center) Function: Cis to trans face – modifying cargo as they move (ex. Glycoproteins – Golgi removes sugar monomers and substitutes others, producing a large variety of carbohydrates) Before dispatching products through vesicles in trans face – molecular identification tags (adding phosphate groups) to aid in sorting by acting like ZIP codes on mailing labels. 5. GOLGI BODIES (shipping and receiving center) Function: Transport vesicles budded from the Golgi may have external molecules on their membranes that recognize “docking sites” on the surface of specific organelles or on the plasma membrane, this, targeting the vesicles appropriately.  6. LYSOSOMES Structure: spherical membranous sac organelles that contain hydrolytic enzymes within single membranes Function: breaks down food particles, invading objects, or worn out cell parts The Lysosome Functions: Recycling cellular components (autophagy) Cell suicide (suicide is bad for cells, but good for us!) (The lysosome is not found in plant cells) Function: phagocytosis This bacterium about to be eaten (phagocytocis – Greek phagein to eat, and kytos – vessel, referring here to the cell) by an immune system cell will spend the last minutes of its existence within a lysosome.  Tay-Sachs disease - The cells of people with inherited lysosomal storage diseases lack a functioning hydrolytic enzyme normally present in lysosomes. The lysosomes become engorged with indigestible substrates, which begin to interfere with other cellular activities - a lipid-digesting enzyme is missing or inactive, and the brain becomes impaired by an accumulation of lipids in the cells. Fortunately, lysosomal storage diseases are rare in the general population. Tay-Sachs Disease Tay-Sachs Disease  7. MITOCHONDRIA Structure: folded membrane within an outer membrane, the folds of the inner membrane are called cristae Function: converts energy stored in food into usable energy for work & cellular respiration The Mitochondrion Think of the mitochondrion as the powerhouse of the cell. Both plant and animal cells contain many mitochondria. (Mitochondria is the plural of mitochondrion)  The Mitochondrion A class of diseases that causes muscle weakness and neurological disorders are due to malfunctioning mitochondria. Worn out mitochondria may be an important factor in aging. Mitochondrial Diseases  8. CYTOPLASM Structure: The cytoplasm consists of cytosol (fluid), the cytoskeleton (filamentous structures), and the organelles (excluding the nucleus). It is a gel- like matrix that occupies most of the cell's interior. Function: Site for various metabolic reactions, suspends organelles, enables intracellular transport, buffers against external changes, and supports the overall shape and structure of the cell. It plays a critical role in maintaining cellular function and health.  9. Peroxisomes Structure: spherical organelles that contain enzymes within single membranes Function: Degrade hydrogen peroxide, a toxic compound that can be produced during metabolism. 10. Cytoskeleton Structure: a network of thin, fibrous elements made up of microtubules (hollow tubes) and microfilaments (threads made out of actin) Function: acts as a support system for organelles -maintains cell shape  10.1. Centrioles Structure: composed of nine sets of triplet microtubules arranged in a ring. Exist in pairs. An example of microtubules Function: centrioles play a major role in cell division (mitosis) 10.2. CILIA AND FLAGELLA Structure: hair-like organelles that extend from the surface of cells ○ When they are present in large numbers on a cell they are called cilia ○ When they are less numerous and longer they are called flagella ○ Both organelles are composed of nine pairs of microtubules arranged around a central pair. Function: cell motility 10.2. Cilia & Flagella Cilia on a protozoan Beating sperm tail at fertilization Smoker’s cough is due to destruction of cilia linking the airways. 10.2. CILIA & FLAGELLA The Cytoskeleton in Action A white blood cell using the cytoskeleton to “reach out” for a hapless bacterium. MICROFILAMENTS MICROFILAMENTS MICROFILAMENTS SPECIALIZED PLANT CELL ORGANELLES Cells In a Leaf 1. CELL WALL Structure: rigid wall made up of cellulose, proteins, and carbohydrates Function: boundary around the plant cell outside of the cell membrane that provides structure and support 2. Vacuoles Structure: a sac of fluid surrounded by a membrane ○ Very large in plants Function: used for temporary storage of wastes, nutrients, and water  3. Plastids There are three types of plastids in plant cells: ○ Chloroplasts (discussed on next slide) ○ Chromoplasts: synthesize and store pigments ○ Leucoplasts: store food such as starches, proteins, and lipids Chromoplasts Leucoplasts Red Pepper Flower 4. CHLOROPLASTS Structure: stacked sacs (thylakoids) that contain chlorophyll surrounded by a double membrane Function: photosynthesis (conversion of light energy to chemical energy stored in the bonds of glucose)  The Chloroplast Think of the chloroplast as the solar panel of the plant cell. Only plants have chloroplasts, but animals reap the benefits too. A Consequence of Cell Walls – the Great Strength of Woody Plants  Micrographs of a Plant Cell and an Animal Cell Elodea Human Cheek Cells  CELL FUNCTIONS 1. Provide Structure and Support Like a classroom is made of bricks, every organism is made of cells. While some cells such as the collenchyma and sclerenchyma are specifically meant for structural support, all cells generally provide the structural basis of all organisms. For instance, skin is made up of a number of skin cells. Vascular plants have evolved a special tissue called xylem, which is made of cells that provide structural support.  CELL FUNCTIONS 2. Facilitate Growth Through Mitosis In complex organisms, tissues grow by simple multiplication of cells. This takes place through the process of mitosis in which the parent cell breaks down to form two daughter cells identical to it. Mitosis is also the process through which simpler organisms reproduce and give rise to new organisms.  CELL FUNCTIONS 2. Facilitate Growth Through Mitosis  CELL FUNCTIONS 3. Allow Passive and Active Transport Cells import nutrients to use in the various chemical processes that go on inside them. These processes produce waste which a cell needs to get rid of. Small molecules such as oxygen, carbon dioxide and ethanol get across the cell membrane through the process of simple diffusion. This is regulated with a concentration gradient across the cell membrane. This is known as passive transport. Mechanisms of Membrane Transport  CELL FUNCTIONS 3. Allow Passive and Active Transport Larger molecules, such as proteins and polysaccharides, go in and out of a cell through the process of active transport in which the cell uses vesicles to excrete or absorb larger molecules. Energy flow in ecosystems  CELL FUNCTIONS 4. Produce Energy An organism's survival depends upon the thousands of chemical reactions that cells carry out relentlessly. For these reactions, cells require energy. Most plants get this energy through the process of photosynthesis, whereas animals get their energy through a mechanism called respiration.  CELL FUNCTIONS 5. Create Metabolic Reactions Metabolism includes all the chemical reactions that take place inside an organism to keep it alive. These reactions can be catabolic or anabolic. The process of energy production by breaking down molecules (glucose) is known as catabolism. Anabolic reactions, on the other hand, use energy to make bigger substances from simpler ones.  CELL FUNCTIONS 6. Aids in Reproduction Reproduction is vital for the survival of a species. A cell helps in reproduction through the processes of mitosis (in more evolved organisms) and meiosis. In mitosis cells simply divide to form new cells. This is termed asexual reproduction.  CELL FUNCTIONS 6. Aids in Reproduction Meiosis takes place in gametes or reproductive cells where there is a mixing of genetic information. This causes daughter cells to be genetically different from the parent cells. Meiosis is a part of sexual reproduction. Meiosis  Nerve & Glial cells under SEM The key to every biological problem must finally be sought in the cell, for every living organism is, or at some time has been, a cell. E.B. Wilson, 1925  SECTION 4 MICROSCOPY  MICROSCOPES A microscope is a very powerful magnifying glass A microscope helps you see things like cells up close  3 Types of Microscopes simple microscope has only 1 lens. compound microscope has 2 sets of lenses. It can magnify things 100 - 200 times larger than they really are. electron microscope can magnify objects up to 300,000 times. They do not use lenses, but use electrons to enlarge the image.  Magnification and Resolution Magnification: refers to the microscope’s power to increase an object’s apparent size Resolution: refers to the microscope’s power to show detail clearly Light Microscope Light Microscope Elodea - Aquatic Plant 40X 400X Transmission Electron Microscope (TEM) Transmission Electron Microscope (TEM) Herpes Virus Plant Root Cell Scanning Electron Microscope (SEM) Scanning Electron Microscope (SEM) Scanning Electron Microscope (SEM) Mosquito Head 200X 2000X Scanning Electron Microscope (SEM) Fly Eye Scanning Electron Microscope (SEM) Surface of Neuron Tongue Inside of Stomac Scanning Electron Microscope (SEM) Yeast Pollen Red Blood Cell, Platelet, and White Blood Cell copyright cmassengale 138 Different parts of a microscope THANK YOU FOR LISTENING! Iwasa, J., & Marshall, W. (2016). Karp's Cell and Molecular Biology: Concepts and Experiments 8th Edition. USA: John Wiley & Sons, Inc. REFERENCES Reece, J. B., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V., & Jackson, R. B. (2011). Campbell Biology 9th Edition. San Francisco, California: Pearson Education Inc.