Honors Biology Ch. 4 Notes

Honors Biology Chapter 4 Notes INTRODUCTION History 1. Contributing Scientists A.) Robert Hooke (1665)  looked at cork under a microscope, identified and named cells. B.) Anton Von Leeuwenhoek (1666)  Dutch. Was the first person to identify microorganisms. C.) Mattias Schleiden (1838)  German. Found that all plants are composed of cells. D.) Theodor Schwann (1839)  German. Found that all animals are made of cells. E.) Rudolph Virchow* (1858)  German. Concluded that all cells come from pre-existing cells. * Disputed the theory of spontaneous generation 2. Cell Theory A.) All living things are made of cells. B.) All cells come from other cells. * Omnis cellula e cellula – Latin. From cells come cells. 3. Terminology A.) cyte or cyto = cell * cytology – the study of cells * erythrocyte – a red blood cell ADDITIONAL INFORMATION: 1. micrographs – a photograph taken through a microscope

4.1: Microscopes ADDITIONAL INFORMATION: 1. light microscope (LM) – works by passing visible light through a specimen. 2. magnification – the increase in apparent size of an object. 3. resolution – a measure of the clarity of an image. 4. electron microscope (EM)* – uses a beam of electrons 5. scanning electron microscope (SEM)* – used to study the detailed architecture of cell surfaces. * Cannot be used to study living things. 6. transmission electron microscope (TEM) – used to study the details of internal cell

structure. 4.2: Cell Size READ 4.3: Cell Types 1. There are two basic cell types A.) prokaryotic – smaller, less complex. 1-10µm. (“Before Nucleus”) bacteria and archaea. B.) eukaryotic – Larger, more complex. 10-100 µm. protests, fungi, plants and animals. 2. Features shared by ALL CELLS A.) Bound by a plasma membrane B.) Contain DNA as hereditary info. C.) Contain ribosomes (small structures that synthesize proteins) D.) Filled with cytoplasm* * fluid-filled region between the nucleus and the plasma membrane (water and solutes; sugars, lipids, proteins) 3. Prokaryotic Cells A.) key features: 1. Do NOT have: a.) nucleus b.) organelles 2. DO have: a.) pili – help attach it to surfaces b.) capsule – surrounds the cell wall and further protects the cell surface. Also helps the cell stick to things. (is sugar-based) c.) nucleoid region (DNA) – no membrane surrounds it. d.) cell wall (protein bond) – protects the cell and helps maintain its shape. e.) prokaryotic flagella (flagellum) – helps it move. ADDITIONAL INFORMATION: 1. ribosomes – make proteins according to instructions from the genes.

4.4: Eukaryotic Cells 1. Defining features

A.) Nucleus B.) Compartmentalized – divided into different compartments C.) Contain organelles (complexity) *Organelles 1. sub-cellular structures 2. membrane bound 3. have unique internal environments 2. List of Organelles: A.) ALL eukaryotic cells have (organelles): 1. Nucleus a.) nuclear envelope b.) nuclear pores c.) nucleoplasm d.) nucleolus e.) chromatin (DNA) 2. Rough Endoplasmic Reticulum (Rough ER) 3. Smooth Endoplasmic Reticulum (Smooth ER) 4. Golgi apparatus (bodies) 5. Transport vesicles 6. Mitochondrion B.) Plant Cells ONLY (organelles) 1. Chloroplast 2. Central Vacuole C.) Animal ONLY 1. Lysosome D.) Protist ONLY 1. Contractile vacuole 3. Other Cellular Structures A.) Animal Only 1. Flagella 2. Cilia 3. Centrioles B.) Plant ONLY 1. Cell Wall C.) ALL CELLS 1. plasma membrane (cell membrane) 2. ribosomes 3. cytoplasm – the fluid-filled region between the nucleus and the plasma membrane 4. DNA ADDITIONAL INFORMATION: 1. Cellular metabolism – the chemical activities of cells

4.5: Cell Structures 1. Nucleus A.) Function 1. Controls all cellular activity – brain 2. Storage of DNA a.) chromosomal DNA (chromatin/ heredity) - 46 chromosomes (38,000 genes) B.) Structure 1. Surrounded by membrane (nuclear envelope) - Nuclear pores allow passage 2. Contains nucleoplasm (water + solutes) 2. Nucleolus A.) Function: 1. ribosome synthesis B.) Structure: 1. Made of proteins 2. Housed in nucleus 3. Ribosomes A.) Function 1. protein synthesis B.) Structure 1. Made of protein and RNA C.) Types: 1. Free Ribosomes a.) local protein synthesis 2. Bound Ribosomes a.) secreted proteins 4. Rough Endoplasmic Reticulum A.) Function: 1. Protein synthesis a.) secretion b.) packed *Case of Insulin *Glycoprotein *Oligosaccharide 2. Membrane synthesis ADDITIONAL INFORMATION:

Rough ER often adds sugar to a polypeptide, making a glycoprotein. Transports glycoprotein to the Golgi Apparatus 5. Smooth Endoplasmic Reticulum A.) Function 1. lipid synthesis a.) cholesterol b.) sex hormones c.) adrenal gland (DHEA and adrenaline) 2. Metabolism of carbohydrate a.) glycogen 3. Detoxification of drugs and poisons a.) liver cells b.) alcohol induces proliferation of smooth ER 4. Storage of calcium ions (necessary for muscle contraction) 6. Golgi Apparatus A.) Function 1. processing, modification, sorting, shipping of molecules produced by the ER 2. Synthesis of some molecules (sugars): hyaluronic acid B.) Structure 1. Consists of several stacks of cisterna 2. Cis face – receiving in transport 3. trans face – shipping vesicles ADDITIONAL INFORMATION: The modified proteins become part of the plasma membrane itself or part of another organelle 7. Lysosome A.) Function 1. Digestion of macromolecules *Intracellular Digestion 2. Recycling of materials (autophagy*) *phagy = eating *tadpoles *humans B.) Structure 1. membrane bound sac 2. contains hydrolytic enzymes 3. pH = 5 (the cell cytoplasm is about pH 7) C.) Examples of Function: 1. phagocytosis – when a cell eats another cell a.) amoeba

b.) macrophage:

lysosome

bacteria

food vacuole

D.) Storage Diseases 1. Pompe’s Disease - liver damage/ glycogen 2. Taysach’s Disease - brain damage/ lipids 8. Vacuoles A.) Types of vacuoles 1. Central Vacuole (plants) 2. Contractile Vacuole (protist) 3. food vacuole (animal) B.) Functions 1. central vacuole A.) storage - organic compounds - ions - waste materials - pigments - poisons (defense) - water C.) Structure of central vacuole 1. membrane bound sac 2. surrounding membrane = tonoplast ADDITIONAL INFORMATION: Central vacuole absorbs water and becomes larger as a result. The central vacuole is vital at maintaining the cell’s internal environment. 9. Peroxisome A.) Function 1. Various metabolic tasks 2. Example: H2O – catalose  H2O + O2 B.) Structure: 1. membrane bound sac 2. contains metabolic enzymes

10. Mitochondrion A.) Function: - site of cellular respiration *energy producer C6H12O6 + O2  CO2 + H2O + energy B.) Structure 1. Surrounded by double membrane 2. 1-10µm long 3. contains DNA (mDNA)

Mitochondrion

cristae (folds of the intermembrane) mitochondrial matrix intermembrane space outermembrane

intermembrane 11. Plasma Membrane A.) Function 1. regulate passage of molecules *security B.) Structure 1. composed of phospholipids 12. Chloroplast A.) Function: - photosynthesis (CO2 + H2O -- sunlight  C6H12O6 + O2) B.) Structure:

thylakoid disc

grana

intermembrane

intermembrane space

outermembrane

stroma (fluid)

13. Cytoskeleton A.) Function: 1. shape and support of cell 2. movement a.) cell b.) organelles B.) Structure: 1. Microtubules – made of tubulin – originate from (grow out of) centriole. Main structural components of cilia and flagella. (anchor organelles, act like tracks for organelle movement and also guide the movement of chromosomes when cells divide.) 2. Microfilaments – solid rods composed of mainly globular proteins called actin, arranged in a double chain. (support structure) 3. Intermediate filaments – made of fiberous proteins and have a ropelike structure. (reinforce cell shape, anchor certain organelles like the nucleus) 14. Cilia A.) Function -swimming or sweeping 15. Flagella A.) Function: -swimming 16. Cell Wall A.) Function 1. Structure 2. Shape B.) Structure 1. Made of Cellulose 17. Centrioles A.) Function -cell reproduction