Podcast
Questions and Answers
What is the basic unit of length according to the text?
What is the basic unit of length according to the text?
- Nanometer (nm) (correct)
- Micrometer (µm)
- Millimeter (mm)
- Angstrom (Ã…)
What is the magnification capability of an electron microscope compared to a light microscope?
What is the magnification capability of an electron microscope compared to a light microscope?
- 1000x
- In excess of 100,000x (correct)
- 100x
- 10x
What physical phenomenon causes the bending of light rays when they change medium?
What physical phenomenon causes the bending of light rays when they change medium?
- Diffraction
- Dispersion
- Reflection
- Refraction (correct)
What is the fraction equivalent of 10 nanometers (nm) in meters?
What is the fraction equivalent of 10 nanometers (nm) in meters?
What is the maximum magnification capability of electron microscopes?
What is the maximum magnification capability of electron microscopes?
Why are lenses and specimens in electron microscopes required to be in a vacuum?
Why are lenses and specimens in electron microscopes required to be in a vacuum?
Which type of electron microscope is used to observe fine cell structure details?
Which type of electron microscope is used to observe fine cell structure details?
What is the purpose of staining techniques in microscopy?
What is the purpose of staining techniques in microscopy?
What are basic dyes attracted to in staining techniques?
What are basic dyes attracted to in staining techniques?
What is the most commonly used stain for distinguishing Gram-positive from Gram-negative bacteria?
What is the most commonly used stain for distinguishing Gram-positive from Gram-negative bacteria?
Which staining technique is used to detect organisms with high concentrations of mycolic acid in their cell walls?
Which staining technique is used to detect organisms with high concentrations of mycolic acid in their cell walls?
What is the technique that uses fluorescent antibodies to tag specific proteins?
What is the technique that uses fluorescent antibodies to tag specific proteins?
What is the purpose of differential staining?
What is the purpose of differential staining?
Which staining technique involves one dye?
Which staining technique involves one dye?
What is the purpose of SEM in electron microscopy?
What is the purpose of SEM in electron microscopy?
Why is staining necessary in microscopy?
Why is staining necessary in microscopy?
What are the shapes of cocci and rods (bacilli) bacteria?
What are the shapes of cocci and rods (bacilli) bacteria?
What are examples of bacteria mentioned in the text?
What are examples of bacteria mentioned in the text?
What is the function of the cytoplasmic membrane in bacteria?
What is the function of the cytoplasmic membrane in bacteria?
What types of molecules can pass through the cytoplasmic membrane without the need for transport proteins?
What types of molecules can pass through the cytoplasmic membrane without the need for transport proteins?
What is the purpose of transport proteins in bacteria?
What is the purpose of transport proteins in bacteria?
Which type of transport system moves substances against a concentration gradient and requires energy?
Which type of transport system moves substances against a concentration gradient and requires energy?
What do bacteria use protein secretion systems for?
What do bacteria use protein secretion systems for?
What distinguishes between gram-positive and gram-negative bacteria?
What distinguishes between gram-positive and gram-negative bacteria?
What is the main component of the cell wall in bacteria?
What is the main component of the cell wall in bacteria?
What is the function of the cell wall in bacteria?
What is the function of the cell wall in bacteria?
What are the different types of bacterial groupings mentioned in the text?
What are the different types of bacterial groupings mentioned in the text?
What are the sizes of vibrio, spirillum, and spirochete bacteria mentioned in the text?
What are the sizes of vibrio, spirillum, and spirochete bacteria mentioned in the text?
What distinguishes major types of bacteria in the Gram stain?
What distinguishes major types of bacteria in the Gram stain?
What is the waxy coat produced by Mycobacterium that repels the Gram stain?
What is the waxy coat produced by Mycobacterium that repels the Gram stain?
What is the main component of the rigid cell wall found only in bacteria?
What is the main component of the rigid cell wall found only in bacteria?
What are the components of peptidoglycan?
What are the components of peptidoglycan?
How is the peptidoglycan cross-linked?
How is the peptidoglycan cross-linked?
What is unique to the cell wall subunit of bacteria?
What is unique to the cell wall subunit of bacteria?
What does the Gram-positive cell wall contain in addition to the thick peptidoglycan layer?
What does the Gram-positive cell wall contain in addition to the thick peptidoglycan layer?
What is the function of teichoic acids in the Gram-positive cell wall?
What is the function of teichoic acids in the Gram-positive cell wall?
What is the distinguishing feature of the Gram-negative cell envelope?
What is the distinguishing feature of the Gram-negative cell envelope?
What is the function of the outer membrane in the Gram-negative cell envelope?
What is the function of the outer membrane in the Gram-negative cell envelope?
What is the main function of the architecture of the bacterial cell envelope?
What is the main function of the architecture of the bacterial cell envelope?
What does resolution refer to in microscopy?
What does resolution refer to in microscopy?
What is the function of immersion oil in bright-field microscopes with 100x lenses?
What is the function of immersion oil in bright-field microscopes with 100x lenses?
What is the resolving power of electron microscopes compared to bright-field microscopes?
What is the resolving power of electron microscopes compared to bright-field microscopes?
What is the purpose of dark-field microscopes in microscopy?
What is the purpose of dark-field microscopes in microscopy?
What is the limitation of the resolution of a light microscope?
What is the limitation of the resolution of a light microscope?
What is the function of staining cells with dyes or electron-dense material in microscopy?
What is the function of staining cells with dyes or electron-dense material in microscopy?
What is the total magnification when using ocular (10x) and objective (40x) lenses in a compound microscope?
What is the total magnification when using ocular (10x) and objective (40x) lenses in a compound microscope?
What does the refractive index measure in microscopy?
What does the refractive index measure in microscopy?
What is the increase in the apparent size of an object compared to its actual size called in microscopy?
What is the increase in the apparent size of an object compared to its actual size called in microscopy?
What is the ability to see objects against the background called in microscopy?
What is the ability to see objects against the background called in microscopy?
What is the limitation of the resolution of an electron microscope?
What is the limitation of the resolution of an electron microscope?
Flashcards are hidden until you start studying
Study Notes
Microscopy Principles and Techniques
- Refractive index measures the relative speed of light as it passes through a medium and is used by lenses to focus light.
- Lenses use refraction to bend light and focus it based on the principles of refraction.
- Magnification is the increase in the apparent size of an object compared to its actual size and is expressed as a ratio, e.g., "100,000x".
- Resolution is the ability to see objects as distinct instead of a blur and is defined as the minimum distance at which two points can be distinguished as individuals.
- Contrast is the ability to see objects against the background, and techniques like staining cells with dyes or electron-dense material can improve contrast in microscopy.
- Bright-field microscopes are the most common in laboratories and use a series of magnifying lenses to evenly illuminate the entire field of view.
- Compound microscopes have ocular (10x) and objective (4x, 10x, 40x, 100x) lenses, with the total magnification being the product of the magnifying power of both lenses.
- The resolution of a light microscope is limited to 0.2µm due to the physical limitation of visible light, making it unable to see details of viruses.
- Bright-field microscopes with 100x lenses require immersion oil to displace air and prevent light from missing the objective lens.
- Dark-field microscopes direct light towards the specimen at an angle, allowing only scattered light to enter the objective and creating a bright image against a dark background.
- Electron microscopes use electromagnetic lenses, electrons, and a fluorescent screen to replace glass lenses, visible light, and the eye, with a resolving power about 1,000-fold greater than bright-field microscopes.
- The wavelength of electrons is about 1,000 times shorter than light, and the resolving power of electron microscopes is approximately 0.3 nm.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
