- Largest organelle.
- When stained shows darkened patches-kromatin
- Surrounded by nuclear envelope
- Made of two membranes with fluid between them.
- Holes called nuclear pores- go through envelope.
- Allow relitively large moilecules to pass through
- Dense, spherical structure (nucleolous) inside nucleus.
- Houses nearly all cells genetic information.
- Chromatin consists of DNA and proteins- instuctions for making proteins.
- Some proteins regulate cells acivities.
- When cells divide chromatin condenses into visible chromosomes.
- Nucleolous makes RNA and ribosomes.
- These pass into cytoplasm and proteins are assembled at them.
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- Consists of series of flattened membrane bound sacs called cisternae.
- Continuous with outer nuclear membrane.
- Rough endoplasmic reticulum is studded with ribosomes.
- Smooth endoplasmic reticulum is not.
- Rough ER transports proteins that were made on the attatched ribosomes.
- Some of these proteins may be secreted from cell.
- Some will be placed on cell surface membrane.
- Smooth ER is involved in making lipids the cell needs.
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- Stack of membrane bound flattened sacs.
- Recieves proteins from ER and modifies them
- May add sugar molecules to them.
- Packages modified proteins into vesticles to be transported.
- Some modified proteins may go to the surface of cell to be secreted
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- May be spherical or sausage shaped.
- Two membranes seperated by fluid.
- Inner membrane is highly folded to form cristae.
- Central part of mitochondria is matrix.
- Where ATP is produced during respiration.
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- Found only in plant cells and cells of some protoctists.
- Two membranes seperated by fluid filled space.
- Inner membrane is continuous with elaborate network of flattened membrane sacs called thylakoids.
- Site of photosynthesis in plant cells.
- Light energy is used to drive the reactions of photosynthesis.
- From this carbohydrate is made from water and carbon dioxide.
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- Spherical sacs surrounded by single membrane.
- Contain powerful digestive enzymes that break down materials.
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- Tiny organelles
- Some in cytoplasm and some are bound to ER.
- Each ribosome consists of two subunits.
- Site of protein synthesis in the cell.
- Act as assembly line where coded information (mRNA) from nucleus is used to assemble proteins from amino acids.
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- Small tubes of protein fibres (microtubules)
- pair of them next to nucleus in animal cells and cells of some protocists.
- Take part in cell division
- Form fibres known as the spindle
- Move chromosomes during nuclear division.
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