Cell Theory All organisms are made of cells The cell is the smallest unit of matter that is living New cells come from existing cells Cells can differ substantially from one another but share common features Cells are too small to be seen by the naked eye so we use microscopes Two basic types of Electron Microscopes Ems are used to study subcellular structures 1 Scanning electron microscopes SEMs focus a beam of electrons onto the surface of a specimen providing images that look 3 D 2 Transmission electron microscopes TEMs focus a beam of electrons through a specimen and are usually used to study the internal structure of the cells Most cells are between 1 and 100 nanometers diameter the yellow portion 1 m 0 1 m 1 cm 1 mm 100 m 10 m 1 m 100 nm 10 nm 1 nm e y e d e d i a n U Human height Length of some nerve and muscle cells Chicken egg Frog egg Human egg Most plant and animal cells Nucleus Most bacteria Mitochondrion Smallest bacteria Viruses Ribosomes Proteins Lipids Small molecules 0 1 nm Atoms M L M E Super resolution microscopy Semifluid substance within the membrane known as Cytosol Common features of all cells Bounded by a Plasma Membrane Contain Chromosomes Ribosomes Prokaryotic Cells DNA is concentrated in the nucleoid not enclosed by a membrane Lack membrane bounded organelles Contain ribosomes plasma membrane cell wall capsule jelly like outer coating when dormant flagella locomotion organelles Ex bacteria and archaea Eukaryotic Cells Generally larger than prokaryotic cells Chromosomes located in a membrane enclosed organelle Nucleus Membranous Nuclear Envelope encloses nucleus Variety of membrane bounded organelles suspended in cytosol Test Q All of the following are part of a prokaryotic cell except A plasma membrane Ribosomes DNA An endoplasmic reticulum A cell wall Which of the following is present in a prokaryotic cell ER Mitochondrion Chloroplast Nuclear Envelope Ribosome This limits cell size The lower the surface area to volume ratio is the slower diffusion affects cells Cells with a low surface area to volume ratio are inefficient Nucleus contains most of genes in eukaryotic cell Nuclear envelope double membrane seperates contents from cytoplasm Nucleolus makes ribosomes from DNA instructions Chromatin complex of DNA and proteins DNA wrapped around histones like a spool Ribosomes not real organelle b c not membrane bound Use DNA info to make proteins free ribosomes in cytosol bound ribosomes outside of ER or nuclear envelope Endomembrane System Regulates protein traffic and performs metabolic functions in the cell Includes Plasma Membrane Selective barrier that allows sufficient passage of oxygen nutrients and wastes to the rest of the cell Consists of Quiz Q Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules Proteins Steroids Starches Lipids Glucose o Double layer of phospholipids o Various proteins attached to embedded in it o Hydrophilic and Hydrophobic region o Carbohydrate side chains on surface receptor molecules for hormones etc o Cholesterol lowers the freezing temp of the membrane Endoplasmic Reticulum o Rough ER beaded with ribosomes creates secretory proteins i e glycoproteins protein with covalently bonded carb involved in cell cell recognition which depart in transport vesicles Is also the membrane factory of the cell o Smooth ER outer surface lacks ribosomes synthesizes lipids metabolizes carbs detoxes drugs poisons stores calcium ions Quiz Q Which type of organelle is primarily involved in the synthesis of oils phospholipids and steroids Smooth endoplasmic reticulum Mitochondrion Contractile Vacuole Lysosome Ribosome Quiz Q Which structure is the site of synthesis of proteins that may be exported from the cell Tight junctions Rough ER Golgi Vesicles Lysosomes Plasmodesmata The liver is involved in detoxification of many poisons and drugs Which of the following structures is primarily involved in this process and therefore abundant in liver cells Golgi Apparatus consists of flattened membranous sacs called cisternae o Vesicles move from ER Golgi cis face receiving side Golgi modifies sorts and ships out of trans face Nuclear envelope Golgi apparatus Rough ER Smooth ER Transport Vesicles Lysosomes digestive organelle where macromolecules are hydrolyzed digested Is acidic Lysosomal membranes and hydrolytic enzymes are made by rough ER Golgi Apparatus o Phagocytosis lysosome digesting food by fusing with vacuole and digesting it with hydrolytic enzymes o Autophagy lysosome breaking down damaged organelles damaged organelle becomes surrounded by double membrane lysosome fuses with this vesicle and hydrolytic enzymes digest its components Vacuole large vesicles derived from E R and Golgi Many functions i e food vacuoles formed by phagocytosis contractile vacuoles pump excess H2O out of freshwater protist cells central vacuoles in plants help plants grow In animal cells hydrolytic enzymes are packaged to prevent general destruction of cellular components Which of the following organelles functions in this compartmentalization Chloroplast Lysosome Central Vacuole Glyoxysome Peroxisome Tay Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large complex lipids Which cellular organelle must be involved in this condition Membrane bound ribosomes The ER The Golgi apparatus Mitochondria The lysosome Endomembrane System Review nucleus and nucleolus endomembrane system ribosomes mitochondria plastids the cytoskeleton and cilia flagella and centrioles Mitochondria and Chloroplasts convert energy to forms that cells can use for work Cyanide binds with at least on molecule involved in producing ATP if a cell is exposed to cyanide most of the cyanide would be found within the Lysosomes Ribosomes ER Mitochondria Peroxisomes Mitochondria cellular respiration in animals Converts oxygen sugars fats other fuels ATP cristae infoldings Chloroplasts site of photosynthesis in plants contain green pigment chlorophyll Composed of envelope consisting of two membranes separated by intermembrane space thylakoids flattened interconnected sacs granum stack of thylakoids poker chips stroma fluid outside the thylakoids contains chloroplast DNA ribosomes and many enzymes Both mitochondria and chloroplasts contain their own ribosomes and a small amount of DNA Peroxisomes are oxidative organelles They are specialized metabolic compartments bounded by a single