Page 117 - Fundamentals of anatomy physiology

Spotlight Figure 3–7
Protein Synthesis, Processing, and Packaging

The Golgi apparatus plays a major role in modifying and packaging newly synthesized proteins. Some
proteins and glycoproteins synthesized in the rough endoplasmic reticulum (RER) are delivered to the
Golgi apparatus by transport vesicles. Here’s a summary of the process, beginning with DNA.

1 Protein synthesis 2 The mRNA leaves 3 Proteins 4 Protein synthesis 5 The proteins are
begins when a the nucleus and constructed on on fixed ribosomes then modified
gene on DNA produces attaches to a free free ribosomes are occurs at the RER. The within the ER. Regions
messenger RNA ribosome in the released into the newly synthesized of the ER then bud off
(mRNA), the template cytoplasm, or a fixed cytosol for use within protein folds into its forming transport
for protein synthesis. ribosome on the RER. the cell. 3-dimensional shape. vesicles containing
modified proteins and
glycoproteins.

Ribosome 3 Protein

DNA released into
cytoplasm

Rough ER

5

1 4

mRNA

2

Cytosol

Nucleus

Transport
vesicle

Nuclear
pore

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