GRE Subject Test: Biochemistry, Cell, and Molecular Biology : GRE Subject Test: Biochemistry, Cell, and Molecular Biology

Study concepts, example questions & explanations for GRE Subject Test: Biochemistry, Cell, and Molecular Biology

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All GRE Subject Test: Biochemistry, Cell, and Molecular Biology Resources

1 Diagnostic Test 201 Practice Tests Question of the Day Flashcards Learn by Concept

Example Questions

Example Question #2 : Endoplasmic Reticulum And Golgi Apparatus

Which of the following is a function of the smooth endoplasmic reticulum?

Possible Answers:

Ribosome production

Triglyceride production

Macromolecule digestion 

Protein synthesis

Correct answer:

Triglyceride production

Explanation:

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.

Example Question #1 : Endoplasmic Reticulum And Golgi Apparatus

Where in the cell does new membrane synthesis take place?

Possible Answers:

In the endoplasmic reticulum

In the Golgi apparatus

In the ribosomes

In the mitochondria

In the lysosome

Correct answer:

In the endoplasmic reticulum

Explanation:

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.

Example Question #1 : Endoplasmic Reticulum And Golgi Apparatus

Which of the following organelles has the function of storing intracellular calcium?

Possible Answers:

Endoplasmic reticulum 

Lysosome

Nucleolus

Golgi complex

Autophagosome

Correct answer:

Endoplasmic reticulum 

Explanation:

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.

Example Question #1 : Endoplasmic Reticulum And Golgi Apparatus

What is the primary function of the Golgi apparatus?

Possible Answers:

Protein sorting

All of these are primary functions of the Golgi apparatus

Maintaining the secretory pathway

Post-translational modifications of proteins

Correct answer:

All of these are primary functions of the Golgi apparatus

Explanation:

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.

Example Question #2 : Help With Golgi Apparatus Function

Which of the following GTP-binding proteins is associated with COPI during vesicle assembly and budding in the cis-Golgi?

 

Possible Answers:

SAR1A

ATPases

Soluble NSF attachment protein receptor (SNARE)

ADP ribosylation factors (ARFs)

Glycosidases

Correct answer:

ADP ribosylation factors (ARFs)

Explanation:

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.

Example Question #41 : Cellular Structures And Functions

Each of the following functions are associated with the Golgi apparatus, except __________.

Possible Answers:

Delivery of proteins to the lysosome

Contains resident proteins required for the electron transport chain (ETC)

Formation of proteoglycans for the extracellular matrix

Post-translational modifications to proteins to aid in their sorting

Delivery of proteins to the plasma membrane

Correct answer:

Contains resident proteins required for the electron transport chain (ETC)

Explanation:

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. 

Example Question #41 : Cell Biology

Which of the following proteins are abundant in the extracellular matrix?

Possible Answers:

Tubulin

Collagen

Myosin

Actin

Correct answer:

Collagen

Explanation:

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.

Example Question #1 : Extracellular Matrix

Which of the following proteins is a transmembrane protein responsible for anchoring the extracellular matrix (ECM)?

Possible Answers:

Laminin

Integrins

Fibronectin

Collagen 

Correct answer:

Integrins

Explanation:

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.

Example Question #2 : Extracellular Matrix

Which of the following is correct about integrins?

Possible Answers:

They facilitate integration of foreign DNA into a host genome by homologous recombination

They promote conjugative pili firing through motile force during bacterial conjugation 

None of the other answers are correct

They synthesize fibronectin, vitronectin, collagen, and laminin

 

They anchor the cell to the extracellular matrix (ECM) and relay signals from the ECM to the cell

Correct answer:

They anchor the cell to the extracellular matrix (ECM) and relay signals from the ECM to the cell

Explanation:

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. 

Example Question #3 : Extracellular Matrix

Which of the following is the primary structural component of the basal lamina?

Possible Answers:

Entactin

Microfilaments

Laminins

Type IV collagen

Integrins

Correct answer:

Type IV collagen

Explanation:

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. 

All GRE Subject Test: Biochemistry, Cell, and Molecular Biology Resources

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