Identify organelle A and list three of its functions. Identify the process and enzyme in the equation. Explain the importance of this process to mammals.

20. a) The organelle marked A is the Golgi apparatus (or Golgi complex/body).

b) Three functions of the Golgi apparatus are:

• Modifying, sorting, and packaging proteins and lipids synthesized in the endoplasmic reticulum.
• Forming lysosomes, which contain digestive enzymes.
• Synthesizing carbohydrates and attaching them to proteins and lipids to form glycoproteins and glycolipids.

21. a) The process that represents the above equation is deamination.

b) The enzyme represented by x is deaminase.

c) The importance of deamination to mammals is:

• It removes excess amino acids from the body that cannot be stored.
• It converts the carbon skeletons of amino acids into useful forms like glucose or fat for energy or storage.
• It detoxifies ammonia, a toxic byproduct of amino acid breakdown, by converting it into less toxic urea for excretion.