A-LevelBiologyCell structure9700/22 · Oct/Nov 2018 · Q66 Marks

As a red blood cell matures, cell organelles are lost from the cell. This provides more space for the haemoglobin molecules that have been synthesised.

(a)The red blood cell has a short lifespan due to the loss of the nucleus and other organelles. State one function performed by each of the organelles listed, before they are lost from the developing red blood cell. rough endoplasmic reticulum Golgi body centrioles[3]
(b)State the most appropriate term to match each of the descriptions A to C. A The part of the haem group that binds oxygen in each haemoglobin polypeptide. B The compound formed when carbon dioxide binds to haemoglobin. C The compound formed when hydrogen ions (H+) bind to haemoglobin.[3]

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2018). The mark or mark type is shown in brackets.

[1] rough endoplasmic reticulum protein / polypeptide / named protein, synthesis / transport / modification; A post-translational modification / examples named protein e.g. haemoglobin, carbonic anhydrase, membrane proteins
[1] Golgi body modification / processing, of, proteins / lipids A post-translational modification / examples / makes proteins functional or packaging (molecules) into vesicles or formation of, Golgi / secretory, vesicles or forms (primary) lysosomes;
[1] centrioles formation of, spindle fibres / spindle or microtubule organisation;
[1] A iron / Fe; I oxidation status of Fe A iron atom / iron ion R iron molecule
[1] B carbaminohaemoglobin;
[1] C haemoglobinic acid;

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