Microscopy and cell structures. Flashcards
Microscopy and cell structures.
What is meant by magnification?
The extent to which the actual size if the object is enlarged into a image.
What is meant by resolution?
The ability to distinguish between 2 points.
What is the equation triangle for microscopy.
Image size
Magnification Actual size
How do you calibrate a microscope?
Place a stage micrometer on the stage of the microscope.
Line up one of the divisions on the eyepiece graticule with a fixed point on the stage micrometer.
Count the number of divisions on the eyepiece graticule that correspond with a set measurement on the stage micrometer.
Calculate the distance in micrometres of one division on the eyepiece graticule
What is a TEM microscope?
Transmission electron microscope.
How does a TEM microscope work?
Electron beams pass through the specimen .
What is a SEM Microscope?
Scanning electron microscope.
How does a SEM microscope work?
Electron beams are aimed at the specimen.
Electrons are reflected back from the specimen and detected.
What is the function of the nucleus?
Contains genetic information.
Give some key feature of the nucleus.
Surrounded by nuclear envelope.
Contains chromatin.
Contains a nucleolus.
What is the function of the mitochondria?
ATP production through aerobic respiration.
Give some key features of the mitochondria.
Double membrane - inner membrane folds to form cristae .
Internal fluid is called the matrix.
What is the function of the lysosome?
Breaking down waste. (Old organelles ).
Give some key features of lysosomes.
Specialised vesicles containing hydrolytic enzymes .
What is the function of the smooth endoplasmic reticulum?
Lipid and carbohydrate synthesis.
Give some key features of the smooth ER?
Contain flattened membrane-bound sacs called cisternae.
What is the function of the rough endoplasmic reticulum?
This is where protein synthesis happens.
Give some key features of the rough ER.
Cisternae bound to ribosomes.
Have ribosomes on the surface.
What is the function of the golgi apparatus?
Modifies proteins and packages them into vesicles.
Give some key features of the golgi apparatus.
Contains ribosomes.
Has flattened sacs.
What is the function of The cytoskeleton?
Maintains cell shape.
Control of cell movement and of organelle movement in cells.
Compartmentalisation of organelles.
Give some key features of the cytoskeleton.
It is made up of microfilaments to control cell movement and cytokinesis.
It is also made up of microtubules to regulate shape and organelle movements. They form centrioles and spindle fibres. .
What is the function of the flagella and cilia?
Flagella Enables cell movement.
Cilia move substances across cell surface.
Explain the differences between eukaryotic and prokaryotic cells,
Prokaryotic cells have a singe strand of DNA not enclosed in a nucleus like a eukaryotic cell.
Prokaryotic cells have smaller ribosomes (70S) eukaryotic have larger (80S).
Some prokaryotic cells have flagella.
Prokaryotic cell walls is made up of peptidoglycan and the cell walls of a eukaryotic cell is made up of chitin.
