The smooth endoplasmic reticulum lacks ribosomes on its surface, meaning it does not participate in protein translation. It does play a key role in the production of various lipids, such as phospholipids and triglycerides.

The endoplasmic reticulum (ER) is the cellular organelle responsible for membrane synthesis. Products from the ER are moved to the Golgi, where they are tagged and shipped off to their final destination. Lysosomes are important for degradation and ribosomes play a role in translation. Mitochondria are for energy production in the form of ATP.

The endoplasmic reticulum, while crucial to protein synthesis, is also an intracellular calcium storage organelle, and calcium can be released in response to signaling cascades as needed. None of the other organelles listed participates in storage of calcium.

The Golgi apparatus is a complex organelle with many various functions. These functions are primarily dedicated to protein modification, protein packaging, and protein sorting. Some of post-translational modifications that take place in this organelle include glycosylation and phosphorylation. The Golgi apparatus is an important relay in the secretory pathway, as it produces the vesicles that contain most secreted peptides.

The correct answer is ADP ribosylation factors (ARFs). ARFs are active when bound by GTP, and inactive when bound by GDP. The active GTP-bound form of ARF binds the vesicle coat protein 1 (COPI), to faciliate vesicle budding from the cis-Golgi face.

The Golgi apparatus is considered the post office of the cell; proteins are received, sorted, modified, and sent to their final cellular destination. The proteins required for the electron transport chain are localized to the mitochondria, and are not within the Golgi apparatus, thus this is the correct selection. 

Actin and tubulin, which forms microtubules, are components of the cytoskeleton. While the extracellular matrix is linked to the cytoskeleton, these proteins are not large components of the matrix. Myosin is a motor protein that largely interacts with actin in muscle tissue. Collagens are the most abundant proteins in the extracellular matrix and have many important functions, including helping maintain cell and tissue structure.

The only choice that is actually a transmembrane protein is "integrins." This class of protein has several important functions, including anchoring the extracellular matrix to the cell. Integrins serve as the connection between the actin cytoskeleton and the extracellular matrix. Integrins directly interact with fibronectins to help hold important proteins, such as collagens and laminins, in place. These proteins, however, are located outside of the cell and are not embedded in the membrane.

The correct answer is that integrins anchor the cell to the extracellular matrix (ECM) and relay signals from the ECM to the cell. Integrins are transmembrane receptors that bind ECM ligands such as fibronectin, vitronectin, collagen, and laminin to relay messages to the cell, ultimately regulating transcription of genes involved in the cell cycle, cell shape, and motility. 

Type IV collagen is the major component of the basal lamina, which is a crucial sub-foundation for many tissue types and epithelia. Laminins and entactin are found in the basal lamina, but there is more Type IV collagen. Integrins and microfilaments are proteins with important structural functions in other contexts.