structure of a generalized cell -plasma membrane -cytoplasm: cytosol organelles -nucleus bio130 lab...
TRANSCRIPT
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 3.24
-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 SkinFrog Skin(simple squamous epithelium)(simple squamous epithelium)
4X objective(40X)
10X objective(100X)
40X objective(400X)
Pentagon cells with visible nuclei
Teased Smooth MuscleTeased Smooth Muscle 4X objective(40X)
10X objective(100X)
40X objective(400X)
Long, stringy cells with enlargements at nuclei
Human Sperm CellHuman Sperm Cell 4X objective(40X)
10X objective(100X)
40X objective(400X)
Tiny cells with visible nuclei and long flagella
Human Blood SmearHuman Blood Smear(red blood cells)(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 TransportDiffusion 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 MembraneDiffusion: 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 TransportDiffusion 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 MembraneDiffusion: 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
Beaker Sac Initial weight
Final weight
Weight change
Tests- beaker fluid
Tests- sac fluid
1 Water 40% Glucose
X grams
2 40% Glucose
40% Glucose
X grams
3 Water 10% NaCl
X grams
4 Water 40% Sucrose Congo Red Dye
X grams
Diffusion Through Nonliving Membranes
Beaker Sac Initial weight
Final weight
Weight change
Tests- beaker fluid
Tests- sac fluid
1 Water 40% Glucose
X grams
more increase
2 40% Glucose
40% Glucose
X grams
3 Water 10% NaCl
X grams
4 Water 40% Sucrose Congo Red Dye
X grams
Diffusion Through Nonliving Membranes
Beaker Sac Initial weight
Final weight
Weight change
Tests- beaker fluid
Tests- sac fluid
1 Water 40% Glucose
X grams
more increase yellow
++glucose
2 40% Glucose
40% Glucose
X grams
3 Water 10% NaCl
X grams
4 Water 40% Sucrose Congo Red Dye
X grams
Diffusion Through Nonliving Membranes
Beaker Sac Initial weight
Final weight
Weight change
Tests- beaker fluid
Tests- sac fluid
1 Water 40% Glucose
X grams
more increase yellow
++glucose
orange
+++glucose
2 40% Glucose
40% Glucose
X grams
3 Water 10% NaCl
X grams
4 Water 40% Sucrose Congo Red Dye
X grams
Diffusion Through Nonliving Membranes
Beaker Sac Initial weight
Final weight
Weight change
Tests- beaker fluid
Tests- sac fluid
1 Water 40% Glucose
X grams
more increase yellow
++glucose
orange
+++glucose
2 40% Glucose
40% Glucose
X grams
same none X X
3 Water 10% NaCl
X grams
4 Water 40% Sucrose Congo Red Dye
X grams
Diffusion Through Nonliving Membranes
Beaker Sac Initial weight
Final weight
Weight change
Tests- beaker fluid
Tests- sac fluid
1 Water 40% Glucose
X grams
more increase yellow
++glucose
orange
+++glucose
2 40% Glucose
40% Glucose
X grams
same none X X
3 Water 10% NaCl
X grams
more increase
4 Water 40% Sucrose Congo Red Dye
X grams
Diffusion Through Nonliving Membranes
Beaker Sac Initial weight
Final weight
Weight change
Tests- beaker fluid
Tests- sac fluid
1 Water 40% Glucose
X grams
more increase yellow
++glucose
orange
+++glucose
2 40% Glucose
40% Glucose
X grams
same none X X
3 Water 10% NaCl
X grams
more increase cloudy
++
NaCl
4 Water 40% Sucrose Congo Red Dye
X grams
Diffusion Through Nonliving Membranes
Beaker Sac Initial weight
Final weight
Weight change
Tests- beaker fluid
Tests- sac fluid
1 Water 40% Glucose
X grams
more increase yellow
++glucose
orange
+++glucose
2 40% Glucose
40% Glucose
X grams
same none X X
3 Water 10% NaCl
X grams
more increase cloudy
++
NaCl
4 Water 40% Sucrose Congo Red Dye
X grams
much more
big increase
Diffusion Through Nonliving Membranes
Beaker Sac Initial weight
Final weight
Weight change
Tests- beaker fluid
Tests- sac fluid
1 Water 40% Glucose
X grams
more increase yellow
++glucose
orange
+++glucose
2 40% Glucose
40% Glucose
X grams
same none X X
3 Water 10% NaCl
X grams
more increase cloudy
++
NaCl
4 Water 40% Sucrose Congo Red Dye
X grams
much more
big increase
blue_
sucrose
Diffusion Through Nonliving Membranes