Structure of a Generalized Cell -plasma membrane -cytoplasm: cytosol organelles -nucleus BIO130 Lab 2 Exercise 4 The Cell: Anatomy

A Quick Tour Through A Cell Play TourOfAnimalCell.mpg

-phospholipid bilayer -separates cell contents from environment Plasma membrane

Ribosomes -site of proteins synthesis -free in cytoplasm or -bound to endoplasmic reticulum

Endoplasmic Reticulum (ER) -membrane tubes and sacs -two types: RER & SER

Rough ER -membrane sacs studded with ribosomes -synthesizes proteins for use in plasma membrane or for secretion

Smooth ER -membrane tubules -site of lipid synthesis, lipid metabolism, drug detoxification, & ion storage

Golgi Apparatus -stack of membrane sacs -has associated vesicles -modifies, sorts, & packages proteins for export or use in plasma membrane

Role of the Golgi Apparatus

Lysosomes -membrane vesicles -contain digestive enzymes -break down old organelles, large molecules, & pathogens

Peroxisomes -membrane sacs -contain oxidases -neutralize free radicals and toxins

Mitochondria -double membrane wall -inner membrane folded into cristae -oxidize food to generate ATP - “powerhouse of the cell”

Centrioles -paired cylindrical bodies -organize mitotic spindle during mitosis -form base of cilia and flagella

Cytoskeleton Figure protein filaments -create internal framework of cell: for structure & support -important in cell mobility

Nucleus -in center of cell -contains DNA: genetic material

Nuclear Envelope Nucleoli -double membrane -separates nuclear contents from cytoplasm -has pores to allow molecule exchange with cytoplasm -dense area in nucleus -site of ribosome production

Chromatin -loose, thread-like DNA -open form of DNA found in cells that are not dividing Chromosomes -tightly wound DNA -dense, bar-like form of DNA that forms when cells begin mitosis for cell division (46 in humans)

Frog Skin (simple squamous epithelium) 4X objective (40X) 10X objective (100X) 40X objective (400X) Pentagon cells with visible nuclei

Teased Smooth Muscle 4X objective (40X) 10X objective (100X) 40X objective (400X) Long, stringy cells with enlargements at nuclei

Human Sperm Cell 4X objective (40X) 10X objective (100X) 40X objective (400X) Tiny cells with visible nuclei and long flagella

Human Blood Smear (red blood cells) WBC RBC 4X objective (40X) 10X objective (100X) 40X objective (400X) Tiny round cells: red blood cells lack nuclei, white blood cells have visible and often multi-lobed nuclei

BIO132 Lab 2 Exercise 5 or 5A The Cell: Transport Mechanisms and Cell Permeability The cell membrane: a selectively permeable barrier Play MembraneBarrier.mov Play MembraneSelectivity.swf

Passive Transport Diffusion Through the Plasma Membrane Diffusion: net movement of solutes from an area of high concentration to an area of low concentration until equilibrium is reached. Occurs due to the constant and random motion of molecules. Play Diffusion.mov

Passive Transport: Diffusion Through the Plasma Membrane Diffusion: net movement of solutes from an area of high conc. to an area of low conc. Play FatWaterSolu.mov Play FacilDiffusion.mov Play Diffusion.swf

Passive Transport Diffusion Through the Plasma Membrane Diffusion: net movement of solutes from an area of high concentration to an area of low concentration: requires no energy from the cell -Simple diffusion: through the phospholipid membrane -Facilitated diffusion: through a protein: a channel or a transport protein

Diffusion Through the Plasma Membrane Diffusion: net movement of solutes from an area of high concentration to an area of low concentration until equilibrium is reached Solutes move to bring the system to equilibrium. But what if the solutes are not free to move?

Occurs when the concentration of a solvent is different on opposite sides of a semipermeable membrane Diffusion of water across a semipermeable membrane Osmolarity – total concentration of solute particles in a solution, a driving force of water movement Osmosis: Water molecules come to equilibrium Water moves when the solutes cannot

Isotonic – solutions with the same solute concentration as that of the cytosol: no net movement of water Hypertonic – solutions having greater solute concentration than that of the cytosol: net movement of water out of the cell (can cause crenation) Hypotonic – solutions having lesser solute concentration than that of the cytosol: net movement of water into the cell (can cause lysis) Tonicity – how a solution effects cell volume

Play OsmoticEffectsRBC.mpg

Active Transport Movement against the concentration gradient Requires work/energy input from the cell Play ActiveTransport.swf Play Exocytosis.swf Play Pinocytosis.swf Play Phagocytosis.swf

Phagocytosis: “cell eating”, cell engulfs extracellular material via pseudopods and internalizes it in a vesicle for digestion in the lysosome Pseudopods PlayAmoeba.mpg

Phagocytosis Play Neutrophil.mpg Play MO-phago.mov Play MO-phago2.mov

BeakerSac Initial weight Final weight Weight change Tests- beaker fluid Tests- sac fluid 1Water40% Glucose X grams 240% Glucose X grams 3Water10% NaCl X grams 4Water 40% Sucrose Congo Red Dye X grams Diffusion Through Nonliving Membranes

BeakerSac Initial weight Final weight Weight change Tests- beaker fluid Tests- sac fluid 1Water40% Glucose X grams more increase 240% Glucose X grams 3Water10% NaCl X grams 4Water 40% Sucrose Congo Red Dye X grams Diffusion Through Nonliving Membranes

BeakerSac Initial weight Final weight Weight change Tests- beaker fluid Tests- sac fluid 1Water40% Glucose X grams more increase yellow ++ glucose 240% Glucose X grams 3Water10% NaCl X grams 4Water 40% Sucrose Congo Red Dye X grams Diffusion Through Nonliving Membranes

BeakerSac Initial weight Final weight Weight change Tests- beaker fluid Tests- sac fluid 1Water40% Glucose X grams more increase yellow ++ glucose orange +++ glucose 240% Glucose X grams 3Water10% NaCl X grams 4Water 40% Sucrose Congo Red Dye X grams Diffusion Through Nonliving Membranes

BeakerSac Initial weight Final weight Weight change Tests- beaker fluid Tests- sac fluid 1Water40% Glucose X grams more increase yellow ++ glucose orange +++ glucose 240% Glucose X grams samenoneXX 3Water10% NaCl X grams 4Water 40% Sucrose Congo Red Dye X grams Diffusion Through Nonliving Membranes

BeakerSac Initial weight Final weight Weight change Tests- beaker fluid Tests- sac fluid 1Water40% Glucose X grams more increase yellow ++ glucose orange +++ glucose 240% Glucose X grams samenoneXX 3Water10% NaCl X grams more increase 4Water 40% Sucrose Congo Red Dye X grams Diffusion Through Nonliving Membranes

BeakerSac Initial weight Final weight Weight change Tests- beaker fluid Tests- sac fluid 1Water40% Glucose X grams more increase yellow ++ glucose orange +++ glucose 240% Glucose X grams samenoneXX 3Water10% NaCl X grams more increase cloudy ++ NaCl 4Water 40% Sucrose Congo Red Dye X grams Diffusion Through Nonliving Membranes

BeakerSac Initial weight Final weight Weight change Tests- beaker fluid Tests- sac fluid 1Water40% Glucose X grams more increase yellow ++ glucose orange +++ glucose 240% Glucose X grams samenoneXX 3Water10% NaCl X grams more increase cloudy ++ NaCl 4Water 40% Sucrose Congo Red Dye X grams much more big increase Diffusion Through Nonliving Membranes

BeakerSac Initial weight Final weight Weight change Tests- beaker fluid Tests- sac fluid 1Water40% Glucose X grams more increase yellow ++ glucose orange +++ glucose 240% Glucose X grams samenoneXX 3Water10% NaCl X grams more increase cloudy ++ NaCl 4Water 40% Sucrose Congo Red Dye X grams much more big increase blue _ sucrose Diffusion Through Nonliving Membranes