Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Title: Cell Structures
Description: Microscopes, Micro-organisms, plant and animal cell structure.
Description: Microscopes, Micro-organisms, plant and animal cell structure.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Chapter four
...
- The most frequently used microscope is the light microscope (LM)—like the one used in biology
laboratories
...
– Specimens can be magnified up to 1,000 times the actual size of the specimen
...
-Cells were first observed by Robert Hooke in 1665
...
-Since the days of Hooke and Leeuwenhoek, improved microscopes have vastly expanded our view of
the cell
...
-Resolution is a measure of the clarity of an image
...
Microscopes have limitations
...
– Therefore, the light microscope cannot provide the details of a small cell’s structure
...
- In the 1800s, these studies led to cell theory, which states that
– All living things are composed of cells and
– All cells come from other cells
...
1 b
-Beginning in the 1950s, scientists started using a very powerful microscope called the electron
microscope (EM) to view the ultrastructure of cells
...
-Electron microscopes can
– resolve biological structures as small as 2 nanometers and
– magnify up to 100,000 times
...
-Transmission electron microscopes (TEM) study the details of internal cell structure
...
Section two:
Cell size must
– be large enough to house DNA, proteins, and structures needed to survive and reproduce, but
– remain small enough to allow for a surface-to-volume ratio that will allow adequate exchange with the
environment
...
-Phospholipids form a two-layer sheet called a phospholipid bilayer in which
– Hydrophilic heads face outward, exposed to water, and
– Hydrophobic tails point inward, shielded from water
...
-Some proteins form channels or tunnels that shield ions and other hydrophilic molecules as they pass
through the hydrophobic center of the membrane
...
2 b
Section three:
-Bacteria and Achaea are prokaryotic cells
...
– Prokaryotic and eukaryotic cells have
– A plasma membrane and
– One or more chromosomes and ribosomes
...
– Prokaryotes have a nucleoid and no true organelles
...
-The surface of prokaryotic cells may
– be surrounded by a chemically complex cell wall,
– have a capsule surrounding the cell wall,
– have short projections that help attach to other cells or the substrate, or
– have longer projections called flagella that may propel the cell through its liquid environment
...
3
Section four:
-The structures and organelles of eukaryotic cells perform four basic functions
...
The nucleus and ribosomes are involved in the genetic control of the cell
...
The endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and peroxisomes are involved in
the manufacture, distribution, and breakdown of molecules
...
Mitochondria in all cells and chloroplasts in plant cells are involved in energy processing
...
Structural support, movement, and communication between cells are functions of the cytoskeleton,
plasma membrane, and cell wall
...
22
-The internal membranes of eukaryotic cells partition it into compartments
...
-fig 4
...
-A few exceptions exist
...
– Plant but not animal cells have
– A rigid cell wall,
– Chloroplasts, and
– A central vacuole
...
4b
http://www
...
com/watch?v=zufaN_aetZI
section five:
Title: Cell Structures
Description: Microscopes, Micro-organisms, plant and animal cell structure.
Description: Microscopes, Micro-organisms, plant and animal cell structure.