2.1. Cell structure and organisation

Most living things are made up of cells that act as building blocks of an organism. Cell shape varies based on its function.

Plant cells are usually larger than animal cells.

The main similarities differences are:

Other structures to know:

• rough endoplasmic reticulum (RER): 
• flattened cavities surrounded by a membrane
• holds ribosomes, giving its surface a rough appearance
• function: produce, transport and store proteins
• ribosomes:
• tiny structures that float in cytoplasm or attached to the RER
• is where cells make proteins
• 
  mitochondria:
• site for aerobic respiration
• cells with high rates of metabolism require large numbers of mitochondria to provide sufficient energy

The cytoplasm of all cells contains structures such as ribosomes on rough endoplasmic reticulum (RER) and vesicles.

Almost all cells (except prokaryotes) have mitochondria and RER.

Practice question

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