Cell Ultrastructure Flashcards
Give some functions of the plasma membrane
Selective permeability Transport materials along cell surface Endocytosis and exocytosis Intercellular adhesion Intercellular recognition Signal transduction
What is the limit of resolution?
The minimum distance at which two objects can be distinguished.
By what type of phosphorylation do mitochondria produce ATP.
Oxidative phosphorylation
What protein are micro tubules made out of?
Tubulin
What is a process that occurs in the nucleolus?
Ribosomal RNA synthesis
What does the smooth endoplasmic reticulum do?
Synthesises cholesterol and lipids. Also involved in the detoxification of certain drugs and toxins.
What do ribosomes do?
Provide a surface upon which protein synthesis occurs.
Acts as a catalyst that facilitates the synthesis of proteins.
Site of translation
What is the glycocalyx made out of and what is its function?
Glycoproteins and glycolipids
Gives the cell specificity
What does the rough endoplasmic reticulum?
Synthesis and modification of proteins that are to be packaged. Also synthesis of membrane lipids and proteins.
What is the function of the Golgi apparatus?
Sorts, concentrates, packages and modifies proteins synthesised in the RER.
Where are lysosomes generated?
In the Golgi apparatus
What do mitochondria do?
Generation of ATP by oxidative phosphorylation
Generating heat in brown fat
Assist in the synthesis of certain lipids and proteins
What do lysosomes do?
Contain hydrolytic enzymes that function in intra cellular digestion.
How big in diameter are most human cells?
10-20 micrometres
What is the diameter of a red blood cell?
7.2 micrometres
How many nanometers are in 1mm?
1,000,000
What is a biopsy?
The removal of a small piece of tissue from an organ or part of the body for microscopic examination.
Where can a curettage be used?
Endometrial lining of the uterus.
For a biopsy, where can a needle be used?
Breast, brain, liver, kidney, muscle
Give two tissue fixatives.
Glutaraldehyde
Formaldehyde
Why do tissues need to be fixed?
Cross links are formed between macromolecules
Cellular structure is preserved
Prevents autolysis and putrefaction
What colour does haematoxylin stain?
Blue/purple
What type of components does eosin stain? Acidic or basic?
Basic eg cytoplasmic proteins and extracellular fibres
What does PAS method stain and what colour is it?
Carbohydrates and glycoproteins
Magenta
What colour does Elastic Van Gieson stain collagen?
Stains collagen pink/red
What colour does Elastic Van Gieson stain elastin?
Blue/black
What colour does Elastic Van Gieson stain muscle?
Yellow
Why does an electron microscope have a finer resolution than a light microscope?
Limit of resolution is inversely proportional to wavelength and electrons have a much smaller wavelength than light.
What do peroxisomes do?
Major site of oxygen utilisation and hydrogen peroxide production. Use HP to oxidise other substrates including phenols, alcohol, formic acid and formaldehyde.
What does a cell’s cytoskeleton do?
Maintains and changes cell shape
Provides structural support for plasma membrane and cell organelles
A means of movement for organelles, plasma membranes and other cytosol constituents.
State the meaning of the term ‘tissue’.
A collection of cells specialised to perform a particular function.
List the functions of the nucleus
DNA storage
Co-ordinates the cell’s activities; metabolism, growth, protein synthesis, mitosis
Functions of the nuclear envelope?
Separates nuclear contents from the cell’s cytoplasm
Nuclear pores allow specific types and sizes of molecules to pass through
When does a ribosome bind to the ER?
When it is synthesising a protein bound for the secretory pathway.
At which end of the Golgi body do vesicles fuse at?
The convex cis end.
