BIOLOGICAL SCIENCE I
BIOLOGICAL SCIENCE I BSC 2010
Popular in Course
Popular in Biological Sciences
This 3 page Class Notes was uploaded by Kari Harber Jr. on Thursday September 17, 2015. The Class Notes belongs to BSC 2010 at Florida State University taught by Staff in Fall. Since its upload, it has received 18 views. For similar materials see /class/205429/bsc-2010-florida-state-university in Biological Sciences at Florida State University.
Reviews for BIOLOGICAL SCIENCE I
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/17/15
Topic 6 CELLS STRUCTURE amp FUNCTIONAL COMPONENTS lecture 8 OBJECTIVES 1 Be able to differentiate prokaryotic vs eukaryotic cells 2 Know the classes of major chemical components in the cytosol 3 Know the general structures properties and general function of the major organelles nucleus ER both rough and smooth Golgi apparatus lysosomes and perxisomes 4 Be able to compare and contrast the structure and functions of mitochondria vs chloroplasts 5 Be able to differentiate between the various types of cell junctions Cell the ultimate functional unit of life selfreplicating energytransducing etc however virusesviroids and prions potentially infectious proteins push this de nition further more later Fig 71 cells vary in terms of their size from microscopic to macroscopic large Prokaryotic vs eukaryotic cells 1 prokaryotic fig 74 no distinct nucleus genetic material is not present in a nucleus but rather is aggregated in a nucleoid lack membraneenclosed internal structures organelles characteristically have a capsule which may be the target of antibiotics BACTERIA 2 eukaryotic distinct nucleus and membranebound organelles yeast animal and plant cells Typical animal cell g 77 Typical pant cell g 78 unique structures are chloroplast presence of rigid cell wall central vacuole surrounded by a tonoblast plasma membrane is penetrated with plasmadesmata Cytoplasm the material within the area bounded by the plasma membrane excluding the nucleus includes organelles and the semi uid material referred to as cytosol Cytosol is actually a term which refers to an experimental product of cell isolation If you gently break open cells and then centrifuge the material the cytosol is the semi uid material that does not sediment Cytosol consists mostly of the following 1 water 2 inorganic ions mostly K Cl39 some Na PO4239 and Mg2 trace amounts of Ca2 3 low molecular weight organic compounds glucose free amino acids nucleotides 4 macromolecules proteins enzymes complex carbohydrates Note the cytosol differs radicaly in chemical composition form the fluid that bathes the cells the socalled extracellular or interstitial uid we ll talk about this later There is considerable controversy as to the exact nature of the cytoplasm The traditional view is that it is simply a random mixture of the above components which passively diffuse throughout the intracellular space Others view the cytoplasm as a structured and organized space in which the above components may associate with various regions of the cell In other words distinct compartments may exist even in the absence of membrane barriers Scienti c opinion is beginning to move towards this latter point of view Membranebound compartments Organelles Nucleus contains the bulk of genes note mitochondria and chloroplasts have their own genome g 79 nuclear envelope double membrane perforated by pores inner region is supported by the nuclear lamina which consists of a dense network of protein bers chromatin DNAprotein complexes chromosomes condensed chromatin structures prior to cell division nucleolus organizing center Endoplasmic reticulum ER extensive double membrane system spread throughout the cell according to your text it represents 50 of total membrane in the cell This structure is extensively involved in protein synthesis and packaging as well as other processes including membrane biosynthesis detoxi cation and storing of certain materials There are two basic types of ER 1 smooth ER and 2 rough ER see fig 711 1 smooth ER diverse array of functions biosynthesis of various lipids including steroids fatty acids amp phospholipids conversion of glucose6phosphate to glucose G6Pase glucose6 phophatase detoxi cation of foreign substances converts them into more polar and easily excretable compounds by action ofenzymes known as mixed function oxidases sarcoplasmic reticulum SR in muscle stores and releases calcium more later 2 rough ER studded with ribosomes ribosomes macromolecular complexes consisting of RNA and protein site of translation of genetic message into protein primary site of synthesis of proteins bound for the cell and those that will be secreted to the outside usually are glycoproteins and are wrapped in membrane vesicles Membrane fragments are also made here Golgi Apparatus fig 712 packages vesicles of protein for transport to the exterior Two sides to the structure 1 cis side or face receives materials from the ER reassembles them into laminar type structure and 2 trans side or face new vesicles pinch off form Golgi for transport elsewhere Chemical constituents of membranes are altered during residence in this structure Lysosomes gs 713 amp 714 membrane bound structures that contain degradative enzymes that hydrolyze the major classes of organic compounds engulf and digest materials acquired from the outside by phagocytosis and internal fragments autophagy Formed by the Golgi apparatus Vacuoles membrane bound structures that have a diverse array of functions particles engulfed during phagocytosis become food vacuoles plants have central vacuoles fig 715 which are used to create storage sites for materials such as citric acid Peroxisomes specialized organelles which have enzyme catalyzed reactions that ultimately produce hydrogen peroxide H2O2 as a product H2O2 is highly reactive but there is an enzyme peroxidase that detoxi es H2O2 Mitochondria and Chloroplasts extremely specialized organelles very likely derived in an evolutionary sense from early prokaryotic symbionts of other larger prokaryotic cells Endosymbiontic theory of origin ofeukaryotic cells 1 both mitochondria and chloroplasts have their own genetic info and protein synthetic machinery 2 however a large fraction of proteins in mitochondria and chloroplasts are coded for by genes in the nucleus they are syhthesized on ribosomes in the cytoplasm Mitochondria g 717 1 10 um long except for giant mitochondria from insect ight muscle cells two double membrane systems outer double membrane penetrated by pores which are very selective inner double membrane which is folded to form cristae inner membrane has a large number of peripheral and integral proteins membrane is extremely selective in terms of permeability between the two membranes is the intermembrane space the interior ofthe organelle is known as the matrix functional role is energy conversion Chloroplasts g 718 also have two double membrane systems outer double membrane internal double membrane structures known as thylacoids which are stacked together to form grana membranes have a high concentration of peripheral and integral proteins too the uid region outside the thylacoids is known as the stroma functional role is conversion of light energy into chemical and reducing energy for biosynthesis of sugar from carbon dioxide lntercellular 39unctions some cells are intimately connected to each other
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'