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Flashcards in Cell Structure Deck (20)
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Define Mgnification

How much bigger an image seems compared to the origional object


Define Resolution

The clearness of an image produced by a microscope
Often said as the ability to distinguis between to points of a certain distance apart


What are 4 advantages of a light Microscope

Easy to use
Portable (Field work)
Able to study whole organisms


How do Laser Scanning Microscopes form an image

Scan an object point by point and then transfer that onto a computer


What is the main difference between a TEM and SEM

Transmission electron microscopes fire electrons THROUGH the specimin, whereas SEM bounce electrons off the surface.


Why do you stain a specimin

In order to create contrast and see the specimin easier


What is known as the all purpose stain?

Methylene Blue


What stains DNA and chromosomes dark red

Acetic Orsin


What stains Cytoplasm



What stains lipids

Sudan Red


What stains starch black

Potassium Iodide (Iodine)


What stains cellulose yellow?

Potassium Iodide (Iodine)


How do you use a stage micrometer to calibrate an eyepiece graticule

Place a stage micrometer on the stage and then compare it at your magnification to the eyepiece graticule

Then use I = A x M to work out the size of divisions


What feature of the nuclear envelope allows mRNA to move out

The nuclear pores


What is made in the Nucleolus



What is the Structure and Function of RER

A system of membranes and fluid-filled cavities (cisternae), coated with ribosomes

RER is the transport system of the cell

When the ribosomes on the surface make proteins they instantly move into the RER where they are transported to the Golgi apparatus


What is the Stricture and function of the SER

System of membranes and Cisternae

Contains enzymes involved in synthesis of Cholesterol, lipids and hormones

Also used to transport and absorb lipids


What is the function of the Golgi apparatus

Modification and preparation of materials

E.g proteins can be modified by adding sugar or lipids to make glycoproteins and lipoproteins


Describe the structure of a ribosome

Made in the nucleolus as 2 separate subunits (40s and 60s)

Combine outside the nucleus to form a ribosome


What are the stages of protein synthesis

mRNA instructions made in nucleus

mRNA leaves nucleus through nuclear pore

Binds to a ribosome

Protein is then made in the RER by the ribosome

Pinched off as a vesicle by the RER

Vesicle fuses with Golgi apparatus

Protein is packaged and ready for release

Pinched off as a vesicle

Vesicle fuses with plasma membrane

Membrane opens to release protein outside the cell