First 332 words of the document:
Cellular Ultra structure
Eukaryotic Cells: with nucleus
Cytoplasm: Contains enzymes for glycolosis and other metabolic reactions together with amino
acids, salts, sugars and nucleotides as well as everything else needed by a cell.
Nucleus: Largest organelle surrounded by nuclear envelope which is a double membrane with
nuclear pores, holes containing proteins that control exit of substances. Interior is called
nucleoplasm, this is full of chromatin.
Mitochondria: Sausage-shaped organelle, this is where aerobic respiration takes place. Surrounded
by double membrane, outer is simple and permeable whilst inner is folded into cristae, which give it
a large surface area. The space inside the inner membrane is known as the matrix and contains
circular DNA strands; it is also studded with stalked particles, the site of ATP synthesis.
Ribosomes: Smallest and most numerous of cell organelles, sites of protein synthesis. Composed of
protein and RNA and are manufactured in nucleolus of nucleus. Either found free in cytoplasm
where they make protein for cells use or on RER where they make proteins for export. 80S type.
SER: Series of membrane channels involved in synthesis and transport of materials, mainly lipids
needed by cell.
RER: Same as above, but studded with ribosomes. Involved in synthesis and processing proteins,
before passing them to Golgi for export.
Golgi Body: Flattened membrane vesicles, formed from ER. Involved in transport of proteins from
RER to cell membrane for export. Parts of the RER containing proteins fuse with one side of the
Golgi body membranes, while at the other side small vesicles bud off and move towards the cell
membrane, where they fuse, releasing their contents by exocytosis.
Lysosomes: Membrane bound vesicles formed from RER containing digestive enzymes, used to
break down unwanted chemicals or even whole cells so they can be recycled.
Microvilli: Small, finger-like extensions of the cell membrane, they increase surface area, just
Other pages in this set
Here's a taster:
Cell Membrane: Phospholipid bilayer, thin and flexible, separates cell from outside environment
and controls exit and entry of materials.
Prokaryotic Cells: no nucleus
Cytoplasm: Contains all enzymes needed for function.
Ribosomes: Smaller 70S type.
Nucleoid: Region of cytoplasm that contains DNA, not surrounded by nuclear envelope.
Plasmid: Small circles of DNA, used to exchange DNA between bacterial cells.
Cell Membrane: Same as above.
Mesosome: Tightly folded region containing containing all membrane bound proteins required for
respiration and photosynthesis.…read more