Biology Lab Study Guide: Labs 1-6 Lab #2:
Spectrophotometry: Technique to determine the chemical composition and concentration of sample.
The spectrophotometer: instrument that measures the amount of light transmitted by the sample.
~ 5 key components: a) Light Source = produces white light, combination of all visible wavelengths b) Monochromator (prism shaped)=separates the light c) Subject= sample solution being tested d) Photo detector = converts light energy into electrical energy e) Interpreter: digital display or meter
Electromagnetic Radiation:
* Photons traveling at different speeds of light in a wave-like pattern. * Different forms of electromagnetic radiation have different energies i.e radiowaves have less energy than microwaves (this is because the photons in radio waves have a lower frequency therefore less energy) * Light travels in waves. These waves are vibrations of the electric and magnetic fields that pass through the space.
Lab # 3:
The Microscope:
Compound Microscope:
Magnification: increases it apparent size
Resolution: ability to distinguish between two points as separate points
Contrast: Difference between the lightest and darkest parts of the image, since the specimens are a lot of times transparent, it is usually necessary to stain them with artificial dyes.
Magnification Formula = power of occular lens * power of objective lens
Depth Field Formula =
The Cell:
Cell Theory: All living things or organisms are made up of cells and their products. New cells are created by old cells divided into two. Cells are the basic building block of life.
Prokaryotic Cell:
* Contain two domains, BACTERIA and the ARCHAEA * Don’t have a CELL NUCLEUS * Most of the time they are Unicellular * Cells come in 3 major shapes, Spherical, Rod SHAPED, Spiral
Cyanobacteria = largest prokaryotes
Bacteria =prokaryotic cell that does not contain chlorophyll
Key Components of the cell(*components are also located in eukaryotic cells)
Capsule - Found in some bacterial cells, this additional outer covering protects the cell when it is engulfed by other organisms, assists in retaining moisture, and helps the cell adhere to surfaces and nutrients.
*Cell Wall - Outer covering of most cells that protects the bacterial cell and gives it shape.
Cytoplasm - A gel-like substance composed mainly of water that also contains enzymes, salts, cell components, and various organic molecules.
*Cell Membrane or Plasma Membrane - Surrounds the cell's cytoplasm and regulates the flow of substances in and out of the cell.
Pili - Hair-like structures on the surface of the cell that attach to other bacterial cells. Shorter pili called fimbriae help bacteria attach to surfaces.
*Flagella - Long, whip-like protrusion that aids in cellular locomotion.
*Ribosomes - Cell structures responsible for protein production.
Plasmids - Gene carrying, circular DNA structures that are not involved in reproduction.
Nucleoid Region - Area of the cytoplasm that contains the single bacterial DNA molecule.
The Eukaryotic Cell:
The Eukaryotic cell is present in four types of organisms:
Fungi
Animal
Plant
Protista
Characteristics:
* Have a nucleus (nuclear membrane) * Contains organelles such as MITOCHONDRIA, CHLOROPLASTS and GOLGI BODIES. * Unicellular or multicellular
Components specific to the eukaryote:
Nucleus (nuclear membrane)= the “brain” of the cell, controls all activity within the cell, contains DNA.
Vacuoles/Vesicles: compartments of the cell that store nutrients which form from other membranes within the cell.
*Mitochondria = power source of the cell, makes energy by breaking down sugars. It has both inner and outer membrane which are known as the phospholipid bi-layer.
*Chloroplasts = where photosynthesis take place
*Golgi Complex: packages and delivers materials within and out of the cell.
*all forms of
