2.1 Cell Structure Flashcards
Features of light microscopes
• relatively cheap
•easy to use
•portable and able to be used in the field as well as in laboratories
• able to be used to study whole living specimen
•coloured images
Resolution
The minimum distance between two objects where they can still be seen as two separate objects
Laser scanning microscopes
•high resolution and show high contrast
•have depth of selectivity and can focus on structures at different depths within a specimen
•used in medical profession
•use laser light to scan an object point by point and assemble , by computer
Black and white
What is the rough endoplasmic reticulum (RER)?
a series of flattened sacs enclosed by a
membrane with ribosomes on the surface. RER folds and processes proteins made
on the ribosomes.
What is the smooth endoplasmic reticulum?
a system of membrane bound sacs. SER
produces and processes lipids.
What is the golgi apparatus?
a series of fluid filled, flattened & curved sacs with vesicles surrounding the edges
- processes and packages proteins and lipids
- also produces lysosomes
What is mitohondria?
usually oval shaped, bound by a double membrane called the
envelope. The inner membrane is folded to form projections called cristae with
matrix on the inside containing all the enzymes needed for respiration.
What are centrioles?
are hollow cylinders containing a ring of microtubules arranged at right
angles to each other. Centrioles are involved in cell division
What are ribosomes?
are composed of two sub units and are the site of protein production
What is a lysosome?
a vesicle containing digestive enzymes bound by a single membrane
What is the cytoskeleton?
plays an important role in providing mechanical
strength as well as aiding transport within cells and enabling cell movement
The nucleus
surrounded by a double membrane called the envelope containing pores
which enable molecules to enter and leave the nucleus. The nucleus also contains
chromatin and a nucleolus which is the site of ribosome production
Protein transport
Proteins are produced on the ribosomes
* Proteins which are produced on the surface on RER are folded and processed in the
RER
* The proteins are then transported from the RER to the Golgi apparatus in vesicles
* They are then modified in the Golgi apparatus
* Golgi apparatus packages proteins into vesicles to be transported around the cells o
where they’re required. Some of the proteins such as extracellular enzymes leave the
cell by exocytosis
What is the cell wall?
Rigid outer covering
made of peptidoglycan
What is the capsule?
Protective slimy
layer which helps the cell to
retain moisture and adhere to
surfaces
