Endoplasmic Reticulum: Structure, Function, and Role in Protein Synthesis and Lipid Metabolism

Question 1

Which of the following is the primary function of the Rough Endoplasmic Reticulum (RER)?

Accepted Answer

Protein synthesis and folding

Answer

Lipid metabolism

Answer

Calcium storage

Answer

Nucleic acid synthesis

Question 2

Which of the following is a unique structural feature of the Rough Endoplasmic Reticulum (RER)?

Accepted Answer

Bound ribosomes

Answer

Cisternae

Answer

Fenestrations

Answer

Tubules

Question 3

What is the fundamental difference between the Rough Endoplasmic Reticulum (RER) and the Smooth Endoplasmic Reticulum (SER)?

Accepted Answer

Presence of ribosomes

Answer

Function in lipid metabolism

Answer

Location within the cytoplasm

Answer

Storage capacity

Question 4

Which of the following is a key difference between the RER and SER?

Accepted Answer

Presence of ribosomes

Answer

Location within the cell

Answer

Function in protein synthesis

Answer

Storage capacity

Question 5

What is the primary mechanism by which proteins are transported from the RER to the Golgi apparatus?

Accepted Answer

Vesicular transport via transport vesicles

Answer

Diffusion through the cytoplasm

Answer

Active transport via ion pumps

Answer

Passive transport through osmosis

Question 6

Lipase, a key enzyme involved in lipid metabolism, is primarily associated with which organelle?

Accepted Answer

Smooth Endoplasmic Reticulum (SER)

Answer

Rough Endoplasmic Reticulum (RER)

Answer

Golgi apparatus

Answer

Mitochondria

Question 7

Which of the following diseases is commonly associated with dysfunction of the endoplasmic reticulum (ER)?

Accepted Answer

Cystic fibrosis

Answer

Type 1 diabetes

Answer

Alzheimer's disease

Answer

Parkinson's disease

Question 8

Identify the primary role of the rough endoplasmic reticulum in cells:

Accepted Answer

Protein synthesis and folding

Answer

Lipid metabolism

Answer

Carbohydrate synthesis

Answer

Nucleic acid synthesis

Question 9

Which organelle is responsible for modifying and transporting proteins synthesized in the rough endoplasmic reticulum?

Accepted Answer

Golgi apparatus

Answer

Mitochondria

Answer

Lysosomes

Answer

Peroxisomes

Question 10

Which type of cell lacks an endoplasmic reticulum?

Accepted Answer

Prokaryotic cells

Answer

Muscle cells

Answer

Nerve cells

Answer

Epithelial cells

Question 11

What is the main distinction between smooth and rough endoplasmic reticulum?

Accepted Answer

Ribosome presence

Answer

Lipid metabolism capacity

Answer

Size of the lumen

Answer

Location within the cell

Question 12

Which of the following molecules is NOT synthesized in the endoplasmic reticulum?

Accepted Answer

Nucleotides

Answer

Proteins

Answer

Lipids

Answer

Hormones

Question 13

Describe the function of the endoplasmic reticulum in managing calcium ions:

Accepted Answer

Stores calcium ions to prevent cellular damage

Answer

Releases calcium ions to trigger muscle contractions

Answer

Binds calcium ions to regulate protein synthesis

Answer

Transports calcium ions into the nucleus

Question 14

Which disease is associated with a mutation in a gene encoding an endoplasmic reticulum protein?

Accepted Answer

Cystic fibrosis

Answer

Alzheimer's disease

Answer

Parkinson's disease

Answer

Huntington's disease

Question 15

How does the endoplasmic reticulum contribute to the regulation of cellular metabolism?

Accepted Answer

Synthesizes enzymes involved in metabolic pathways

Answer

Transports metabolites between organelles

Answer

Stores glucose for energy production

Answer

Regulates ion concentrations

Question 16

Describe the structural organization of the endoplasmic reticulum:

Accepted Answer

An extensive network of flattened sacs and tubules

Answer

A single, large sac with a smooth surface

Answer

A cluster of spherical vesicles

Answer

A series of interconnected channels

Question 17

Which technique provides the most direct visualization of the endoplasmic reticulum in cells?

Accepted Answer

Transmission electron microscopy

Answer

Computed tomography

Answer

Magnetic resonance imaging

Answer

Fluorescence microscopy

Question 18

Which organelle is responsible for the modification and sorting of proteins synthesized in the endoplasmic reticulum?

Accepted Answer

Golgi apparatus

Answer

Mitochondria

Answer

Lysosomes

Answer

Ribosomes

Question 19

What type of signal sequence directs proteins to the endoplasmic reticulum?

Accepted Answer

Signal peptide

Answer

Glycosylation tag

Answer

Ubiquitination mark

Answer

Phosphorylation site

Question 20

What is the key distinction between the rough and smooth endoplasmic reticulum?

Accepted Answer

Presence of ribosomes

Answer

Shape and size

Answer

Function

Answer

Membrane composition

Question 21

What is the primary role of ER chaperones in the endoplasmic reticulum?

Accepted Answer

Protein folding and quality control

Answer

Protein transport

Answer

Lipid synthesis

Answer

Protein degradation

Question 22

Which of the following consequences can occur due to prolonged stress in the endoplasmic reticulum?

Accepted Answer

Apoptosis

Answer

Cell division

Answer

Differentiation

Answer

Cell cycle arrest

Question 23

How is the endoplasmic reticulum involved in calcium homeostasis?

Accepted Answer

Calcium storage and release

Answer

Calcium transport

Answer

Calcium synthesis

Answer

Calcium degradation

Question 24

Which of the following diseases is associated with mutations in genes encoding ER proteins?

Accepted Answer

Cystic fibrosis

Answer

Alzheimer's disease

Answer

Huntington's disease

Answer

Down syndrome