8. Rough (20) reticulum bears ribosomes on its outer surface.

9. Freshly synthesised protein is transported via the endoplasmic reticulum to the (21) apparatus where it is processed and packaged in (22)

10. Some protein is (23) out of the cell by vesicles moving towards, and fusing with, the plasma membrane.

11 In addition to carbon, hydrogen ond oxygen proteins always contain (24)

12. A protein consists of sub-units called (25)
(of which there are about 20 types) joined together by peptide bonds to form polypeptides.

13.A molecule of (26) protein consists of parallel (27) chains and has a structural function.

14. A molecule of (28) protein consist of polypeptide chains folded into a spherical shape. Some are structural (e. g. those in the plasma membrane); others act as (29)hormones or (30)

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