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Flashcards in Cell Structure Deck (20)
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1

Define Mgnification

How much bigger an image seems compared to the origional object

2

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

3

What are 4 advantages of a light Microscope

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

4

How do Laser Scanning Microscopes form an image

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

5

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.

6

Why do you stain a specimin

In order to create contrast and see the specimin easier

7

What is known as the all purpose stain?

Methylene Blue

8

What stains DNA and chromosomes dark red

Acetic Orsin

9

What stains Cytoplasm

Eosin

10

What stains lipids

Sudan Red

11

What stains starch black

Potassium Iodide (Iodine)

12

What stains cellulose yellow?

Potassium Iodide (Iodine)

13

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

14

What feature of the nuclear envelope allows mRNA to move out

The nuclear pores

15

What is made in the Nucleolus

Ribosomes

16

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

17

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

18

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

19

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

20

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