Questions and Answers
Which type of endoplasmic reticulum is studded with ribosomes, giving it a 'rough' appearance?
Rough ER
What is the function of the smooth endoplasmic reticulum (SER)?
Lipid biosynthesis
What is the main function of the endoplasmic reticulum (ER)?
Transport of synthesized proteins
What are microsomes?
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What are the two basic types of endoplasmic reticulum?
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What is the function of the rough endoplasmic reticulum (RER)?
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Which type of ER lacks bound ribosomes and is involved in lipid synthesis and detoxification reactions?
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Which function is NOT associated with smooth ER?
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Which organelle plays a major role in the contraction process of muscle cells?
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Which type of ER is involved in protein synthesis and can be detected by staining with basic dyes?
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Which function is associated with smooth ER in liver cells?
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Which organelle is responsible for the synthesis of fatty acids and phospholipids?
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Which organelle is responsible for the degradation of abnormally folded or unfolded proteins in the cytosol?
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During protein translocation, which proteins pass completely into the ER lumen?
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Which type of protein insertion occurs when a polypeptide contains multiple start-transfer and stop-transfer signals?
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What is required for the posttranslational translocation of proteins into the ER?
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What organelle selectively transports ER resident proteins back to the ER?
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What is the self-protective mechanism against ER stress called?
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Which organelle is particularly well developed in protein secreting cells in the exocrine pancreas?
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Which organelle is responsible for the synthesis and transport of proteins within the cell?
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What is the function of the signal sequence or signal peptide in protein synthesis?
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Which Nobel Prize was awarded for the discovery of the signal hypothesis?
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What is the role of protein targeting in the cell?
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Which two types of proteins are translocated co-translationally?
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Which of the following is true about the signal peptide in the process of protein transport into the ER lumen?
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What is the role of the ribosome receptor in protein transport into the ER lumen?
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What is the function of the translocon proteins in the ER membrane?
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What is the role of signal peptidase in protein transport into the ER lumen?
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Which modification occurs in the ER for newly synthesized proteins?
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What is the role of protein disulfide isomerase in the ER lumen?
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Which of the following is NOT a function of cell membranes?
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What is the main structural component of cell membranes?
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Which organelles maintain the characteristic differences between their contents and the cytosol?
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What can ion gradients across membranes be used for?
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What do protein sensors in the plasma membrane do?
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What is the basic fluid structure of the cell membrane?
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What is the main function of the lipid bilayer in the cell membrane?
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What is the main role of specialized membrane proteins in establishing ion gradients?
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How do most molecules move in the cell membrane?
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What is the thickness of the lipid bilayer in the cell membrane?
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Which type of lipid molecule constitutes about 50% of the mass of most animal cell membranes?
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What is the main function of membrane proteins in the plasma membrane?
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What percentage of proteins encoded in an animal's genome are estimated to be membrane proteins?
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Which type of lipid molecule contains a three-carbon glycerol backbone and various fatty acid tails?
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What is the role of cholesterol in eukaryotic plasma membranes?
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Which type of lipid molecule has sugars attached and is found exclusively in the monolayer facing away from the cytosol?
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What is the most common sphingolipid in cell membranes, consisting of a fatty acid tail and a phosphocholine group?
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Which lipid molecule constitutes more than half the mass of lipid in most mammalian cell membranes?
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What is the basic structure that provides the foundation for all cell membranes?
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Which type of lipid molecule contains a hydrophilic or polar end and a hydrophobic or nonpolar end?
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Which structure do phospholipid molecules spontaneously form in aqueous environments?
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Which part of the phospholipid molecules are shielded from water in the bilayer structure?
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What is the function of lipid asymmetry in the lipid bilayer?
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What is the role of the enzyme protein kinase C (PKC) in the lipid bilayer?
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How is the translocation of phosphatidylserine thought to occur in apoptotic cells?
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What is the term used to describe the two-dimensional fluidity of lipid molecules within a lipid bilayer?
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What is the term used to describe synthetic lipid bilayers in the form of spherical vesicles?
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What is the term used to describe synthetic lipid bilayers formed across a hole in a partition between two aqueous compartments or on a solid support?
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What is the term used to describe the process of transferring phospholipids between the inner and outer monolayers of the lipid bilayer?
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What is the term used to describe the nonspecific transfer of phospholipids in both directions between the two monolayers of the lipid bilayer?
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What is the major lipid component of most animal cell membranes?
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Which lipid molecule has a three-carbon glycerol backbone and various fatty acid tails?
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What is the most common sphingolipid in cell membranes, consisting of a fatty acid tail and a phosphocholine group?
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Which type of lipid molecule contains a hydrophilic or polar end and a hydrophobic or nonpolar end?
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What is the role of cholesterol in eukaryotic plasma membranes?
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What is the function of glycolipids in eukaryotic plasma membranes?
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What is the function of the smooth endoplasmic reticulum (SER)?
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What is the function of the rough endoplasmic reticulum (RER)?
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What is the main function of the endoplasmic reticulum (ER)?
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What is the basic structure that provides the foundation for all cell membranes?
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Which type of lipid molecule constitutes the majority of the mass of most animal cell membranes?
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What is the term used to describe the nonspecific transfer of phospholipids in both directions between the two monolayers of the lipid bilayer?
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What is the function of the enzyme protein kinase C (PKC) in the plasma membrane?
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What is the role of cholesterol in eukaryotic plasma membranes?
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What is the term used to describe synthetic lipid bilayers in the form of spherical vesicles?
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What is the main function of lipid asymmetry in the lipid bilayer?
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How do phospholipid molecules spontaneously aggregate in aqueous environments?
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What is the thickness of the lipid bilayer in the cell membrane?
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What is the term used to describe the two-dimensional fluidity of lipid molecules within a lipid bilayer?
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What is the function of the translocator protein in the translocation of phosphatidylserine in apoptotic cells?
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Which of the following is NOT a function of cell membranes?
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Which organelles maintain the characteristic differences between their contents and the cytosol?
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What is the main role of specialized membrane proteins in establishing ion gradients?
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How do most molecules move in the cell membrane?
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What is the basic structure that provides the foundation for all cell membranes?
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What is the role of cholesterol in eukaryotic plasma membranes?
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What is the function of the rough endoplasmic reticulum (RER)?
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What is the main function of membrane proteins in the plasma membrane?
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What is the thickness of the lipid bilayer in the cell membrane?
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Which type of lipid molecule constitutes about 50% of the mass of most animal cell membranes?
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Study Notes
Endoplasmic Reticulum (ER)
- The type of ER studded with ribosomes is called Rough Endoplasmic Reticulum (RER), giving it a 'rough' appearance.
- The function of Smooth Endoplasmic Reticulum (SER) is lipid synthesis and detoxification reactions.
- The main function of ER is protein synthesis and transport.
- Microsomes are fragments of ER.
- The two basic types of endoplasmic reticulum are RER and SER.
Rough Endoplasmic Reticulum (RER)
- RER is involved in protein synthesis and can be detected by staining with basic dyes.
- RER has bound ribosomes.
Smooth Endoplasmic Reticulum (SER)
- SER lacks bound ribosomes and is involved in lipid synthesis and detoxification reactions.
- SER is not associated with protein synthesis.
Cell Membranes
- The main structural component of cell membranes is phospholipids.
- Cell membranes maintain the characteristic differences between their contents and the cytosol.
- Ion gradients across membranes can be used for energy.
- Protein sensors in the plasma membrane detect changes in the environment.
- The basic fluid structure of the cell membrane is a lipid bilayer.
- The main function of the lipid bilayer is to separate the cell from its environment.
- Most molecules move in the cell membrane via lateral diffusion.
- The thickness of the lipid bilayer is 3-4 nm.
Lipid Molecules
- Phospholipid molecules have a hydrophilic or polar end and a hydrophobic or nonpolar end.
- Phospholipid molecules spontaneously form a bilayer structure in aqueous environments.
- Phospholipid molecules are shielded from water in the bilayer structure.
- Lipid asymmetry in the lipid bilayer has vital functions.
- Cholesterol is present in eukaryotic plasma membranes and helps maintain fluidity.
- Sphingolipids have a three-carbon glycerol backbone and various fatty acid tails.
- Phosphatidylserine is a type of phospholipid.
Protein Synthesis and Transport
- During protein translocation, proteins pass completely into the ER lumen.
- The signal sequence or signal peptide is required for protein synthesis.
- The function of the ribosome receptor is protein targeting.
- Translocon proteins in the ER membrane help in protein transport.
- Signal peptidase is involved in protein transport into the ER lumen.
- Protein disulfide isomerase is involved in the ER lumen.
Organelles
- The organelle responsible for protein synthesis and transport is the ER.
- The organelle responsible for the synthesis of fatty acids and phospholipids is the ER.
- The organelle responsible for the degradation of abnormally folded or unfolded proteins in the cytosol is the ER.
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Description
Quiz: Understanding the Golgi Apparatus in Cell Functions Test your knowledge on the Golgi apparatus (GER) and its importance in various cell types! This quiz covers protein secretion in exocrine pancreas cells, collagen and elastin production in connective tissue cells, antibody production in fibroblasts, neurotransmitter production in plasma cells, lysosomal enzyme-containing phagocytic cells, and more. Challenge yourself and enhance your understanding of the Golgi apparatus in cell functions.