Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.
-
Upload
melissa-lindsay-young -
Category
Documents
-
view
227 -
download
5
Transcript of Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.
![Page 1: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/1.jpg)
Chapter 6 A Tour of the Cell
![Page 2: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/2.jpg)
![Page 3: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/3.jpg)
Size of a Nanometer demo
• http://learn.genetics.utah.edu/content/cells/scale/
• Glucose = .9 nm
• Ribosome = 30 nm
• Mitochondria = 4000 nm long
• Skin Cell = 30,000 nm long = 30 um
• 1000 nm = 1 um
![Page 4: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/4.jpg)
Light Microscope - LM
• Uses visible light to illuminate the object.
• Relatively inexpensive type of microscope.
• Can examine live or dead objects.
![Page 5: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/5.jpg)
Resolution• Ability to detect two discrete points as
separate from each other.• As Magnification increases, Resolution
decreases. • LM working limits are100 - 1000X.
![Page 6: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/6.jpg)
Limitations - LM
• Miss many cell structures that are beyond the magnification of the light microscope.
• Need other ways to make the observations.
![Page 7: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/7.jpg)
Light Microscope Variations• Fluorescence: uses dyes to make parts
of cells “glow”.• Phase-contrast: enhances contrasts in
density.• Confocal: uses lasers and special
optics to focus only narrow slides of cells.
![Page 8: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/8.jpg)
![Page 9: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/9.jpg)
![Page 10: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/10.jpg)
Before
After
![Page 11: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/11.jpg)
Electron Microscopes
• Use beams of electrons instead of light.
• Invented in 1939, but not used much until after WWII.
• Electron beam scans surface of the sample, exciting electrons which have their signals detected by a device that translates the pattern of electrons into an electronic signal to a video screen.
![Page 12: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/12.jpg)
TEM – tracheal cell, long cilia were cut longitudinally, others cut to reveal
cross section
SEM rabbit trachea
covered in cilia
![Page 13: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/13.jpg)
Advantages
• Much higher magnifications.
• Magnifications of 50,000X or higher are possible.
• Can get down to atomic level in some cases.
![Page 14: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/14.jpg)
Disadvantages
• Need a Vacuum.
• High cost of equipment.
• Specimen preparation.
• Specimen must be dead
![Page 15: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/15.jpg)
Other Tools for Cytology (study of Cells)
• Cell Fractionation – break the cell apart and separate out the pieces based on their density.
![Page 16: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/16.jpg)
Cell Fractionation
![Page 17: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/17.jpg)
History of Cells
• Robert Hooke - Observed cells in cork.
• Coined the term "cells” in 1665.• 1833 - Robert Brown, discovered the
nucleus.• 1838 - M.J. Schleiden, all plants are
made of cells.• 1839 - T. Schwann, all animals are
made of cells.
![Page 18: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/18.jpg)
Cell Theory
• All living matter is composed of one or more cells.
• The cell is the structural and functional unit of life.
• All cells come from cells.
• http://www.youtube.com/watch?v=mF9U5x6Nxnw
![Page 19: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/19.jpg)
Types of Cells
• Prokaryotic - lack a nucleus and other membrane bounded structures.
• Eukaryotic - have a nucleus and other membrane bounded structures.
![Page 20: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/20.jpg)
Both Have:
• Membrane
• Cytoplasm
• Ribosomes (but the size is different)
![Page 21: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/21.jpg)
Prokaryotic Eukaryotic
Nucleus
![Page 22: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/22.jpg)
Prokaryotic
Eukaryotic
![Page 23: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/23.jpg)
Basic Cell Organization
• Membrane
• Nucleus
• Cytoplasm
• Organelles
![Page 24: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/24.jpg)
Animal Cell
![Page 25: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/25.jpg)
Plant Cell
![Page 26: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/26.jpg)
Membrane
• Separates the cell from the environment.
• Boundary layer for regulating the movement of materials in/out of a cell.
![Page 27: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/27.jpg)
Cytoplasm or Cytosol
• Cell substance between the cell membrane and the nucleus.
• The “fluid” part of a cell.
• Composed of water, dissolved salts and organic molecules (molecules that contain Carbon, dissolved proteins, and the cytoskeleton)
![Page 28: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/28.jpg)
Organelle
• Term means "small organ”. Formed body (or compartment) in a cell with a specialized function.
• Important in organizational structure of cells.
![Page 29: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/29.jpg)
Organelles - function
• Way to form compartments in cells to separate chemical reactions.
• Keeps various enzymes separated in space.
![Page 30: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/30.jpg)
You must be able to:
• Identify the major organelles
• Give their structure
• Give their function
![Page 31: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/31.jpg)
Nucleus
• Most conspicuous organelle.
• Usually spherical, but can be lobed or irregular in shape.
![Page 32: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/32.jpg)
Structure
• Nuclear membrane
• Nuclear pores
• Nucleolus
• Chromatin
![Page 33: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/33.jpg)
![Page 34: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/34.jpg)
Nuclear Membrane
• Double membrane separated by a 20-40 nm space.
• Inner membrane supported by a protein matrix which gives the shape to the nucleus.
![Page 35: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/35.jpg)
Nuclear Pores
• Regular “holes” through both membranes.
• 100 nm in diameter.
• Protein complex gives shape.
• Allows materials in/out of nucleus.
![Page 36: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/36.jpg)
Nucleolus
• Dark staining area in the nucleus.
• 0 - 4 per nucleus.
• Ribosomes are made here
![Page 37: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/37.jpg)
Chromatin
• Chrom: colored
• - tin: threads
• DNA and Protein in a “loose” format. Will form the cell’s chromosomes.
![Page 38: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/38.jpg)
Nucleus - Function
• Control center for the cell.
• Contains the genetic instructions.
![Page 39: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/39.jpg)
Ribosomes
• Structure: 2 subunits made of protein and rRNA. No membrane.
• Function: protein synthesis.
![Page 40: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/40.jpg)
![Page 41: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/41.jpg)
Subunits
• Large:• 45 proteins• 3 rRNA molecules
• Small:• 23 proteins• 1 rRNA molecule
![Page 42: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/42.jpg)
Locations
• Free in the cytoplasm - make proteins for use in cytosol.
• Membrane bound - make proteins that are exported from the cell.
![Page 43: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/43.jpg)
Endomembrane System
• Membranes that are related through direct physical continuity or by the transfer of membrane segments called vesicles.
![Page 44: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/44.jpg)
Endomembrane System
![Page 45: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/45.jpg)
Endoplasmic Reticulum
• Often referred to as ER.
• Makes up to 1/2 of the total membrane in cells.
• Often continuous with the nuclear membrane.
![Page 46: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/46.jpg)
![Page 47: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/47.jpg)
Structure of ER
• Folded sheets or tubes of membranes.
• Very “fluid” in structure with the membranes constantly changing size and shape.
![Page 48: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/48.jpg)
Types of ER
• Smooth ER: no ribosomes.
• Used for lipid synthesis, carbohydrate storage, detoxification of poisons/drugs. Stores Ca ions
• Rough ER: with ribosomes.
• Makes secretory proteins.
![Page 49: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/49.jpg)
Golgi Apparatus
• Structure: parallel array of flattened cisternae. (looks like a stack of Pita bread)
• 3 to 20 per cell.
• Likely an outgrowth of the ER system.
![Page 50: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/50.jpg)
![Page 51: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/51.jpg)
Function of Golgi Bodies
• Processing - modification of ER products (proteins for secretion).
• Distribution - packaging of ER products (proteins for secretion) for transport.
![Page 52: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/52.jpg)
Vesicles
• Small sacs of membranes that bud off the Golgi Body.
• Transportation vehicle for the modified ER products.
![Page 53: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/53.jpg)
Lysosome
• Single membrane.
• Made from the Golgi apparatus.
![Page 54: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/54.jpg)
Function
• Breakdown and degradation of cellular materials.
• Contains enzymes for fats, proteins, polysaccharides, and nucleic acids.
• Over 40 types known.
![Page 55: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/55.jpg)
Lysosomes
• Important in cell death.
• Missing enzymes may cause various genetic enzyme diseases.
• Examples: Tay-Sachs,
![Page 56: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/56.jpg)
Vacuoles
• Structure - single membrane, usually larger than the Golgi vesicles.
• Function - depends on the organism.
![Page 57: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/57.jpg)
Protists
• Contractile vacuoles - pump out excess water.
• Food vacuoles - store newly ingested food until the lysosomes can digest it.
![Page 58: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/58.jpg)
Plants
• Can have a large single vacuole when mature making up to 90% of the cell's volume.
• Function• Water regulation.
• Storage of ions.
• Storage of hydrophilic pigments. (e.g. red and blues in flower petals).
![Page 59: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/59.jpg)
![Page 60: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/60.jpg)
Function: Plant vacuole
• Used to enlarge cells and create turgor pressure.
• Enzymes (various types).
• Store toxins.
• Coloration.
![Page 61: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/61.jpg)
Microbodies
• Structure: single membrane.
• Often have a granular or crystalline core of enzymes.
![Page 62: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/62.jpg)
Function
• Specialized enzymes for specific reactions.
• Peroxisomes: break down fatty acids, detoxify, adds H2 to toxis (it has enzymes in it that convert H2O2 to H20)
• Glyoxysomes: convert lipids into sugars (useful for plant seeds)
![Page 63: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/63.jpg)
Enzymes in a crystal
![Page 64: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/64.jpg)
Mitochondria
• Structure: 2 membranes. The inner membrane has more surface area than the outer membrane.
• Matrix: inner space.
• Intermembrane space: area between the membranes.
![Page 65: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/65.jpg)
![Page 66: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/66.jpg)
Inner Membrane
• Folded into cristae.
• Amount of folding depends on the level of cell activity.
• Contains many enzymes.
• ATP generated here.
![Page 67: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/67.jpg)
Function
• Cell Respiration - the release of energy from food.
• Major location of ATP generation.
• “Powerhouse” of the cell. Comment – be careful NOT to overuse this phrase.
![Page 68: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/68.jpg)
Mitochondria
• Have ribosomes (small size).
• Have their own DNA.
• Can reproduce themselves.
• Likely were independent cells at one time.
![Page 69: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/69.jpg)
Chloroplasts
• Structure - two outer membranes.
• Complex internal membrane.
• Fluid-like stroma is around the internal membranes.
![Page 70: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/70.jpg)
![Page 71: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/71.jpg)
Inner or Thylakoid Membranes
• Arranged into flattened sacs called thylakoids.
• Some regions stacked into layers called grana.
• Contain the green pigment chlorophyll.
![Page 72: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/72.jpg)
Function
• Photosynthesis - the use of light energy to make food.
![Page 73: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/73.jpg)
Chloroplasts
• Contain ribosomes (small size).
• Contain DNA.
• Can reproduce themselves.
• Often contain starch.
• Likely were independent cells at one time (cyano-bacteria).
![Page 74: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/74.jpg)
Cytoskeleton
• Network of rods and filaments in the cytoplasm.
![Page 75: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/75.jpg)
![Page 76: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/76.jpg)
Functions
• Cell structure and shape.
• Cell movement.
• Cell division - helps build cell walls and move the chromosomes apart.
![Page 77: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/77.jpg)
Cytoskeleton Components
• Microtubules
• Microfilaments
• Intermediate Filaments
![Page 78: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/78.jpg)
![Page 79: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/79.jpg)
Microtubules
• Structure - small hollow tubes made of repeating units of a protein dimer.
• Size - 25 nm diameter. Can be 200 nm to 25 m in length.
![Page 80: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/80.jpg)
Microtubules
• Regulate cell shape.
• Coordinate direction of cellulose fibers in cell wall formation.
• Tracks for motor molecules.
![Page 81: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/81.jpg)
![Page 82: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/82.jpg)
Microtubules
• Form cilia and flagella.
• Movement of organelles and chromosomes within the cell
![Page 83: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/83.jpg)
Dynein Protein (Type of microtubule)
• A contractile protein.
• Uses ATP.
• Creates a twisting motion between the microtubules causing the structure to bend or move.
![Page 84: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/84.jpg)
![Page 85: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/85.jpg)
![Page 86: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/86.jpg)
Microfilaments
• 5 to 7 nm in diameter.
• Structure - two intertwined strands of actin protein.
![Page 87: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/87.jpg)
![Page 88: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/88.jpg)
![Page 89: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/89.jpg)
Microfilaments are stained green.
![Page 90: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/90.jpg)
Functions
• Muscle contraction.
• Cytoplasmic streaming.
• Pseudopodia.
• Cleavage furrow formation.
• Maintenance and changes in cell shape.
![Page 91: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/91.jpg)
![Page 92: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/92.jpg)
Intermediate Filaments
• Fibrous proteins that are super coiled into thicker cables and filaments 8 - 12 nm in diameter.
• Made from several different types of protein.
![Page 93: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/93.jpg)
![Page 94: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/94.jpg)
Functions
• Maintenance of cell shape.
• Hold organelles in place.
![Page 95: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/95.jpg)
Cytoskeleton
• Very dynamic; changing in composition and shape frequently.
• Cell is not just a "bag" of cytoplasm within a cell membrane.
![Page 96: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/96.jpg)
Cell Wall
• Nonliving jacket that surrounds some cells.
• Found in:• Plants• Prokaryotes• Fungi• Some Protists
![Page 97: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/97.jpg)
Plant Cell Walls
• All plant cells have a Primary Cell Wall.
• Some cells will develop a Secondary Cell Wall.
![Page 98: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/98.jpg)
![Page 99: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/99.jpg)
Primary Wall
• Thin and flexible.
• Cellulose fibers placed at right angles to expansion.
• Placement of fibers guided by microtubules.
![Page 100: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/100.jpg)
Secondary Wall • Thick and rigid.• Added between the cell membrane and
the primary cell wall in laminated layers.• May cover only part of the cell; giving
spirals. • Makes up "wood”.
![Page 101: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/101.jpg)
Middle Lamella
• Thin layer rich in pectin found between adjacent plant cells.
• Glues cells together.
![Page 102: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/102.jpg)
Cell Walls
• May be made of other types of polysaccharides and/or silica.
• Function as the cell's exoskeleton for support and protection.
![Page 103: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/103.jpg)
Extracellular Matrix - ECM• Fuzzy coat on animal cells.• Helps glue cells together.• Made of glycoproteins and collagen.• Evidence suggests ECM is involved
with cell behavior and cell communication.
![Page 104: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/104.jpg)
![Page 105: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/105.jpg)
Why Are Cells So Small?
• Cell volume to surface area ratios favor small size.
• Nucleus to cytoplasm consideration (control).
• Metabolic requirements.
• Speed of diffusion.
![Page 106: Chapter 6 A Tour of the Cell. Size of a Nanometer demo ells/scale/.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649f515503460f94c73afd/html5/thumbnails/106.jpg)