Microscopy and cell ultra structure Flashcards
Equation of maginification
Magnification= image size/ actual size of specimen
Define resolution
How well the microscope can distinguish between two points that are close together.
Define magnification
How much bigger the image is compared to the actual size.
what is Gram staining
Separates bacteria into two groups, gram positive and gram negative. They add crystal violet and then iodine to fix it in place. They then wash it with alcohol. If stained it is stained it is gram positive and is susceptible to penicillin.
what is Acid fast staining
Acid fast staining is used to differentiate species of micro-bacterium. Carbolfuchsin is applied and washed away. If stained is retained and is red it is micro-bacterium, other bacteria is blue.
What is max magnification and resolution of a light microscope
Max resolution- 0.2u
Max magnification- x1500
Transmission electron microscopes Max resolution and max magnification
Max resolution- 0.0002um
Max magnification- more than x1,000,000
Scanning electron microscopes Max resolution and max resolution
Max resolution- 0.002um
Max magnification- less than x500,000
Advantages and disadvantages of transmission electron microscopes
- provide higher resolution images
- can be used to look at internal structures
- higher magnifications
- but on produces flat images
Advantages and disadvantages of scanning electron microscope
Images produced are 3D rather than 2D
Shows surface features
However it has a lower resolution
what is a Dry mount slide
Specimens are viewed whole or cut into very thin slices. This is called sectioning. After a cover slip is placed over.
what is a Wet mount slide
Specimens are suspended in a liquid. A cover slip is placed over it.
what is a Smear slide
An edge is used to smear the sample creating a thin even coating. A cover slip is then placed over.
Function of nucleus
Controls all the activity of the cell.
Contains genetic code of the cell
Function of nucleolus
Responsible for producing ribosomes
Function of nuclear envelope
A double membrane to protect it from damage in the cytoplasm
what is the Rough endoplasmic reticulum
Covered with ribosomes and and is the site of protein synthesis
what is the Smooth endoplasmic reticulum
Interconnected system of tubules with no ribosomes. Responsible or carbohydrate and lipid synthesis and storage.
what does the Golgi apparatus do
It modifies proteins e.g. Adds carbohydrates chains/sugars or folds them into a specific shape. It then repackages the protein into a vesicles (which buds off). They also make lysosomes and lipids.
what are Ribosomes and what is its structure
Is the site of protein synthesis, where amino acids are assembled into proteins. A 2 subunit organelle made from RNA and protein.
what is the Mitochondria and what does it do
Carry out later stages of respiration and produce ATP. Has a structure called Cristal and a solution called matrix.
what are Lysosomes
A single membrane sac containing hydrolysis enzymes lysozyme. They digest unwanted structures such as dead cells or old organelles.
what do Centrioles do
Helps form spindle fibres involved in division of the cell.
what Plasma membrane do and what is i made up of
Made of lipid and protein. Regulates movement of substances in and out of cells. It also has receptor molecules which allow it to respond to chemical hormones.
