The Cell/ Microscopes Flashcards
(120 cards)
What is the role of water in biological systems?
The solvent of life, dissolving polar and charged molecules due to its polarity.
Water is essential for various biochemical reactions and processes in living organisms.
What are the four main types of macromolecules?
- Carbohydrates
- Lipids
- Proteins
- Nucleic Acids
Each type of macromolecule plays a critical role in biological functions.
Define carbohydrates.
Polymers of sugars (e.g., glucose).
Carbohydrates serve as energy sources and structural components.
What are lipids?
Not true polymers but hydrophobic molecules (e.g., fats, oils).
Lipids are important for energy storage and cellular membrane structure.
What defines proteins?
Polymers of amino acids; their structure is determined by the sequence and properties of amino acids.
Proteins perform a wide array of functions in biological systems.
What are nucleic acids?
Polymers of nucleotides (e.g., DNA, RNA).
Nucleic acids are essential for storing and transmitting genetic information.
What is polymerization?
The process of linking monomers together (dehydration synthesis).
This process is crucial for forming macromolecules.
What is depolymerization?
Breaking down polymers by adding water (hydrolysis).
This process is important for digestion and recycling of biomolecules.
What is the primary structure of proteins?
Linear sequence of amino acids.
The primary structure is critical for determining the protein’s overall structure and function.
What occurs during the secondary structure of proteins?
Formation of a-helices and B-sheets through hydrogen bonding.
Secondary structures contribute to the overall stability of proteins.
Define tertiary structure in proteins.
Folding of the polypeptide into a 3D structure determined by chemistry of amino acid sidechains.
The tertiary structure is essential for the protein’s functional capabilities.
What is quaternary structure in proteins?
Interaction of multiple proteins to form a complex.
Quaternary structure is important for the functionality of multi-subunit proteins.
What are the core principles of cell theory?
- All living organisms are composed of one or more cells
- The cell is the basic unit of structure and function in living organisms
- All cells arise from the division of pre-existing cells
Cell theory is fundamental to understanding biology and the organization of life.
What is light microscopy?
Uses light to view cells and tissues.
Variants include brightfield, darkfield, and phase contrast microscopy.
What is brightfield microscopy?
Direct light transmission, often requires staining for better contrast.
This method is commonly used for observing fixed and stained specimens.
What is darkfield microscopy?
Illuminates the sample from the side, so that only light that is scattered by the specimen reaches the objective lens.
This technique enhances contrast in unstained samples.
What is phase contrast microscopy?
Enhances contrast by shifting in light phases and gives a pseudo-3D appearance to specimens.
This method is useful for viewing live cells and their internal structures.
What is Transmission Electron Microscopy (TEM)?
Provides detailed internal views of thinly sliced samples.
TEM is capable of very high resolution, allowing for the visualization of cellular organelles.
What is Scanning Electron Microscopy (SEM)?
Produces detailed 3D images of surfaces.
SEM is used to study the surface morphology of samples.
What is resolution in microscopy?
The ability to distinguish two objects as separate entities.
What is magnification?
Increasing the apparent size of the specimen, as a lens does.
How does higher magnification affect resolution?
Higher magnification increases resolution.
What is contrast in microscopy?
Enhances the visibility of structures within the sample.
Does contrast increase resolution?
No, it does not increase resolution.