BIOL 130L Exam 2 Review Notes

Biology Notes 2016 Exam 2
 LO 37- draw a cross section of the plasma membrane
o AKA fluid mosaic model
o Components of bilayer
 Integral proteins
 Peripheral proteins
 Cholesterol
 Carbohydrates
 Glycoproteins
 Glycolipids
 Cytoskeleton
 Extracellular matrix
 LO 38- list 6 functions of membrane proteins and describe examples of each
o Transport proteins- transports substances through bilayer
o Enzymatic proteins
o Signal transducens- molecules bind to receptor, which causes enzymatic response by turning cell on/o
 In immune system, antibodies are turned on and off when needed
o Cell to cell recognition- receptors receives another cell and links together temporarily to perform a
function
o Intercellular joining- permanent linking of cells
 Intercalated discs
o Attachment to cytoskeleton and extracellular matrix
 Causes membrane to be dynamic so shape can easily be changed
 Allows connection and influence between outside and inside of cell
 LO 39- draw diffusion, facilitated diffusion, and active transport across biological membranes and give
examples for molecules and bacteria/viruses
o Passive Transport- able to just go through a membrane without help
 Small hydrophobic molecules can diffuse O2, CO2
 Net movement is random/ non directional
 Movement of molecules is dependent on concentration gradient (highlow)
 EX: when breathing, there is a higher concentration of O2 outside of the cell, so O2 moves into the
cell
 Higher concentration of CO2 inside of the cell when inhaling, CO2 moves out of cell when
exhaling
 EX: during exercise, O2 in cell is greater in the muscles so the O2 moves out of the cells, CO2 is
high outside of the cell so it moves into the cell
o Facilitated diffusion- specific channels for larger molecules allow for diffusion
 EX: aquaporins- water channels, only allow H2O through
 Driven by concentration gradient
 Osmosis- diffusion of free water (solvent) not by concentration gradient
o About equal concentration inside and outside of membrane
o Moves toward high concentration of SOLUTE
Hypotonic Isotonic Hypertonic
Anima  More solute in the  Solvent out= solute in  More solute outside so water
l cell H2O moves in  Equal movement in and out leaves the cell
 Cell bursts (lysed)  Shriveled

Plant  Turgid (normal)  Flaccid  Plasmolyzed

,  Active Transport- involves transporter and requires ATP to move molecules from a low
concentration gradient to a high concentration gradient
 Accumulates on one side of the membrane
 EX: in lysosome, protons are pumped out so that pH remains low
 LO 40- diagram and recognize electron micrographs of phagosytosis and 2 types of pinocytosis
o Needed to move large particles across membrane
o Phagocytosis- “cell eating”
 Cell extends itself around object to engulf prey membrane encloses around object
 Can be done by pseudopodium of amoeba
o Micropinocytosis- internalized membrane, membrane pulled into the cell and whatever is around it will
be brought with it
 Differences between types of micropinocytosis is due to different proteins present or not present
 Clathrin and Caveolin- some instances of micropinocytosis will have proteins lining the inside o
the wall, while others will not
 Different cells can vary in size, very large or vary small
 Different types of light microscopy and electron microscopy to view cells
 LO 41- list differences between viruses, bacteria, animal cells and plant cells
o Virus- “toxin”
 Scientists filtered all the particles out of a diseased tobacco plant but there was still something tha
infected the healthy plant
 Not cells, acellular and very small
 No organelles of their own, obtain from hosts so they can grow and reproduce
 RNA or DNA has genetic information
 Do not produce their own ribosomes
o Bacteria
 Single celled
 DNA is genetic information but not bound by a nuclear envelope
 Not a true nucleus nucleoid
 Prokaryote
 Capsule surrounding bacteria allows bacteria to avoid body’s immune response body cannot
recognize
 Can contain the wrong enantiomer D amino acid so body cannot recognize
 Cell wall in most, different composition than plants but provides similar function
 Plasma membrane in all cells
 Ribosomes
 Can have fimbriae or flagella that allows attachment or movement
o Animal Cells
 eukaryote
 Nucleus with nuclear envelope
 Membranous organelles
 Endomembrane system allows communication between nucleus and organelles
o Plant Cells
 Eukaryote
 Similar organelles to animal cells
 Has chloroplasts
 cell wall
 central vacuole