3.2.1 Cell structure

-Surrounded by double membrane called nuclear envelope
-nuclear pores
-chromatin
-Nucleolus which is site of ribosome production

Has double membrane, the inner membrane has folds called cristae. The inside is called the matrix which contains all enzymes needed, ribosomes, DNA which creates some enzymes

Has :
-double membrane
-Thylakoids which contain enzymes and chlorophyll for light dependant reactions. They stack up to make granums.
-Stroma a liquid which contains enzymes for light independent
reactions
- Starch granules
-Loops of dna to create some enzymes
-Ribosomes

Made up of cisternae
RER: Ribosomes on outer surface membrane
Provides Large SA for proteins synthesis and glycoproteins
Provides pathway for transport of materials
SER:
Synthesises , transports and stores LIPIDS AND CARBOHYDRATES

Made up of flattened sacs called cisternae:
-Produces secretory enzymes and carbohydrates.
-Stores and modifies proteins & lipids
-Forms vesicles for transporting proteins/lipids
-Forms lysosomes.

Produced by golgi apparatus and contains digestive enzymes:
destroys material ingested by WBCs.
releases enzymes outside cell to destroy material.
digest worn out organelles

site of protein synthesis

Made up of cellulose/chitin/murein that form fibrils
Provides strength to prevent cell bursting by exerting inward pressure.

Contains cell membrane called tonoplast and cell sap
Makes cell turgid
Contains sugars and amino acids
May contain coloured pigments to attract pollinators.

Minimum distance required between two objects where they can still be seen as separate subjects

cold - slows down enzymes from destroying organelles
buffered - prevent denaturing of enzymes in organelles
isotonic - prevent organelles from bursting

1) Place cells in a cold buffered isotonic solution
2) Break open the cell with a homogeniser. Making a cell homogenate
3) Filter out homogenate to remove debris
4)Place homogenate in a centrifuge at low speeds
Nucleus will fall down and form a pellet while rest is supernatant
Repeat to separate other organelles

Pros:
Cheap
Can view living cells
Coloured images
Cons:
Low magnification
Low resolution

An electron beam is passed through an extremely thin section of the specimen and final image is on a fluorescent screen

Electrons are scattered from the surface of the specimen and detected by electron detectors. Needs to be coated with a metal

Pros:
High magnification
High resolution
Cons:
Expensive
You can get artefacts
cant view living specimens

Have:
Contain no membrane bound organelles
no nucleus
cell wall made of murein
May have:
Capsule
flagellum
Plasmid