Transcript Cellular Processes

How do Cells Work?
Cellular Processes
Cell Permeability
The permitting or activating of the passage
of substances into, out of, or through cells.
(water, nutrients, oxygen, etc.)
Molecular Transport
– Active Transport - Materials require energy to
move through a cell membrane
– Passive Transport - Materials do not requires
help (energy) to move through a cell membrane.
Movement of molecules
Passive Transport
• Diffusion - Movement of molecules from an
area of great concentration to an area of
lesser concentration.
• Osmosis - Passive transport of water
through a cell membrane by diffusion
Cellular Energy
• Cell Respiration - release of energy
from sugar when oxygen is present.
– Aerobic (w/oxygen)
• Fermentation - release of energy
from sugar when oxygen is
insufficient.
– Anaerobic (w/out oxygen)
Energy from Food
• Carbohydrates - organic compounds,
including sugars, starches and fiber that
are the major source of energy for animals.
• Proteins - organic compounds that make up
the structure of cells and direct their
activities.
• Lipids (fats) - organic compounds which
store and release large amounts of energy.
• Nucleic Acids - organic compounds that
store RNA and DNA in cells.
Energy from the Sun
• Photosynthesis - Process by which
producers (plants) change light
energy into chemical energy.
– Only needs light energy, CO2 and H20 to
make sugar.
– Takes place in Chloroplasts inside plant
cells and some algae.
Mitosis -When cells split
• Simple duplication of a cell and all it’s
parts.
• Duplication of DNA into two new cells.
• Phases:
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Prophase - cell gets ready
Metaphase - DNA lines up
Anaphase - separation begins
Telophase - division finishes up
Interphase - normal state of cell
Meiosis - Two Divisions
• For sexual reproduction
• Reproduces a new organism
• Second division divides the
chromosomes in half
• Final phase ends with 4 haploid cells
called gametes (example - egg and
sperm)
Cell Theory
• Cells are the fundamental unit of structure
and function in all living things.
• All living organisms are made of one or
more cells.
• All cells come from other cells through cell
division.
• Cells contain hereditary information
• 1st developed by Theodor Schwann and
Matthias Schleiden
The 1st Microscopes
• Simple lenses used
to make objects
appear larger.
• Zaccharias and
Hans Janssen used
multiple lenses in a
tube to magnify
objects using light
• Simple “light
Microscope”
Robert Hooke 1635-1703
• Used a simple
microscope to
observe objects
including a cork.
• Was the 1st to use
the term “Cell”
Anton van Leeuwenhoek
• 1st to describe
cells and bacteria,
seen through his
microscope
• Was the best
microscope at his
time.
• Known as the
father of
Microscopy
Compound Microscope
• Light microscope
that has two
converging lens
systems: the
objective lens and
the eyepiece.
• Most common and
widely used
microscope
Electron Microscope
• Uses electrons instead
of visible light to
produce highly
magnified images of
objects
• Invented in the 1930’s
and revolutionized the
study of microscopic
objects.
Scanning Electron
Microscope
• Type of electron
microscope capable
of producing highresolution images.
• Images have a
three-dimensional
appearance.
Transmission Electron
Microscope
• A beam of electrons is
transmitted through a
thin specimen, forming
a magnified image and
appears on a screen.
• Useful for viewing
cellular structures
Scanning Tunneling
Microscope
• Obtain atomicscale images
(atomic scale of
2X10-10m)
• Provides a threedimensional image
• Invented in 1981