Foundations in Biology - Cell structure

Magnification

• How much bigger an image appears compared with the original object

Resolution

• The minimum distance apart of two objects to be distinguished

Why do electron microscopes have a higher resolution than light

A beam of electrons has a much smaller wavelength than light

Calibrating

• Line up stage micrometer and eyepiece graticule

• Count how many division on epg fit into one micrometer

• 10um micrometer 10/ number of divisions of epg

Protein synthesis

1. mRNA leaves the nucleus through a nuclear pore.

2. mRNA attaches to a ribosome, in this case attached to RER

3. Ribosome reads the instructions to assemble

   the protein (insulin).

4. Protein molecules are ‘pinched off’ in vesicles and

   travel towards Golgi apparatus

5. Vesicle fuses with Golgi apparatus.

6. Golgi apparatus processes and packages protein molecule - ready for release.

7. Packaged protein molecules are ‘pinched off’ in vesicles from Golgi apparatus

   and move towards plasma membrane.

8. Vesicle fuses with plasma membrane.

9. Plasma membrane opens to release protein molecules outside to cells