overview Flashcards
What is Magnification?
The extent to which the image appears larger compared to the actual object.
How do you calculate magnification?
Magnification = Image size / Actual (real) size.
Define resolution in microscopy
The ability to distinguish two close points as separate; determines the image’s clarity and detail.
What is the field of view?
The visible area under the microscope.
What is the depth of field?
The extent to which the sample remains in focus at different depths.
What is an artefact in microscopy?
A structure that is not part of the specimen, often caused by processing techniques, such as drying out tissue with solvents like acetone.
What is fixation in electron microscopy?
Coating the specimen in heavy metals to prevent electrons from passing through, allowing for imaging.
What does staining do in microscopy?
Injects a resin into the specimen to preserve structures and enhance visibility.
Differentiate between light microscopes and electron microscopes
Light microscopes use visible light to view specimens, while electron microscopes use beams of electrons for higher resolution imaging.
What is the main function of the condenser lens in a light microscope?
It focuses light onto the specimen for better clarity
What are the two main types of sugars in carbohydrates?
Monosaccharides and disaccharides
Define a solute
A substance that dissolves in a solvent.
What is the primary structure of a protein?
The linear sequence of amino acids in a polypeptide chain.
Explain the term “hydrophobic”
Substances that repel water and do not mix well with it; they are non-polar.
What is a triglyceride?
A lipid made up of one glycerol and three fatty acids; commonly found in fats and oils.
What is the role of cholesterol in cell membranes?
It helps maintain fluidity and stability of the membrane by preventing fatty acid tails from packing too closely together.
Define denaturation in the context of enzymes
The disruption of the weak bonds maintaining an enzyme’s specific shape, leading to a loss of function.
describe the function of mRNA in protein synthesis
mRNA carries genetic information from DNA to the ribosome for protein synthesis.
What is the induced fit model of enzyme activity
A model suggesting that when a substrate binds to an enzyme, the enzyme undergoes a slight change in shape to better fit the substrate.
What is the genetic code?
The set of rules by which information encoded in genetic material is translated into proteins, comprising codons that specify amino acids.
What is dehydration in the context of microscopy?
Dehydration preserves structures by making cross-links in the tissue using chemicals like glutaraldehyde and osmium tetroxide.
How does embedding in resin enhance microscopy?
Embedding in resin increases contrast and improves visibility, allowing more detail to be seen.
Describe the function of the denser in a light microscope
The condenser focuses light from the light source onto the specimen for better clarity.
What is the role of the diaphragm/iris in microscopy?
The diaphragm controls the amount of light that passes through the specimen, affecting contrast and brightness.