MTM week 7

Multiple Choice

Glycosylphosphatidylinositol is...

• A transmembrane protein that covalently binds proteins to inner leaflet

• A glycolipid involved in signaling and attaches noncovalently to extracellular proteins

• A glycolipid that covalently anchors peripheral proteins to outer leaflet

• A good friend

Multiple Choice

Which of the following increase membrane fluidity?

I. Unsaturated fatty acids tails

II. Shorter chain fatty acids

III. Increased temp.

• Only I is correct

• Both I & II

• Both I & III

• Both II and III

• All of the above (I, II, III) are correct

Multiple Choice

A patient with alcoholic cirrhosis who shows ascites, an umbilical hernia, and wasting of muscle. His blood work shows and increased reticulocyte count. You also find a distorted cholesterol balance in plasma & RBC membrane, with excess cholesterol present in the RBC membrane.What do you expect to find in this patient? 

• Spur cells

• Acanthocytosis

• Spherocytosis

• Haemolytic anaemia

• sequestration & destruction of RBCs by spleen

Multiple Choice

Influenza virus utilizes lipid rafts in the plasma membrane for viral assembly and budding. What component of lipid rafts would be useful for structural support in the viral envelope?

• G(M1) Ganglioside

• Cholesterol

• Spectrin

• Glycocalyx

• Nucleoporin

Multiple Choice

The surface antigens of an unknown pathogen are negatively charged. The cell membranes of the patient’s cells are also negatively charged, so the pathogen is repelled from the cells. What structures are responsible for the overall negative charge on the outer cell membrane of healthy cells?

• Peripheral proteins expressing serine

• Bilayer fatty acid chains

• Phosphatidylserine

• Sialic acid

Multiple Choice

As a scientist you developed a new drug that specifically blocks the extracellular portion of transmembrane protein transporters. Which of the following processes do you expect to be affected?

I. Uptake of glucose into the cell

II. Binding of cell to ECM

III. Signal transduction of G-coupled receptors

• Only I is correct

• Both I & II

• Both I & III

• Both II and III

• All of the above (I, II, III) are correct

Multiple Choice

Membranes of cells and organelles allow certain types of molecules to pass through but not others. This selectivity is due to the construction of cellular membranes. Cell membranes are made of a lipid bilayer of hydrophobic molecules. The easiest way to visualize this is to imagine pouring vegetable oil into a glass partly filled with water. The vegetable oil which is hydrophobic will float on top of the water In this model, hydrophobic molecules of cell membrane resemble vegetable oil and repel water. Which type of molecule will pass MOST easily through the membrane of a cell or organelle?

• Small and hydrophilic

• Small and hydrophobic

• Large and hydrophilic

Multiple Choice

Plasmapheresis is a process in which the liquid part of the blood, or plasma, is separated from the blood cells. Typically, the plasma is replaced with another solution such as saline or albumin, or the plasma is treated and then returned to your body. Liver transplantation or hepatic transplantation is the replacement of a diseased liver with the healthy liver from another person. Both, plasmapheresis and liver transplantation have been reported as successful treatment for

• Acanthocytosis

• Hereditary SpherocytosisC

• Cholera

• Both “A” and “B” are correct

• All of the above (A, B, C) are correct

Multiple Choice

Which of the following describes the flow of proteins through the Golgi apparatus?

• Cis-Golgi to Golgi stack to trans-Golgi

• Cis-Golgi to trans-Golgi to Golgi stack

• Golgi stack to cis-Golgi to trans-Golgi

• Golgi stack to trans-Golgi to cis-Golgi

Multiple Choice

What is the likely fate of a free-floating protein without a molecular tag located in the Golgi apparatus?

• Cytosolic protein

• Golgi apparatus protein

• Lysosomal protein

• Membrane protein

• Secretory protein

Multiple Choice

A male infant is born with bilateral dislocated hips, restricted shoulder and elbow joints, cloudy corneas, and coarse facial features. 

Which of the following is the location of the dysfunctional enzyme responsible for the most likely diagnosis in this patient?

• Endosomes

• Proteasome

• Golgi apparatus

• RER

• SER

Multiple Choice

You walk into the ER and encounter a peculiar patient. The patient  complains of neck stiffness, dysphagia and lock jaw. The patient states they stepped on a rusty nail, but thought nothing of it. Chances are this patient was exposed to the ____toxin, which degraded ______

• Tetanus / synaptobrevin

• Tetanus / syntaxin

• Botulin / synaptobrevin

• Botulin / syntaxin

Multiple Choice

Lysosomal hydrolases are targeted to the lysosome by the addition of a carbohydrate residue to the protein. An inability to add this carbohydrate leads to a disease in which the lysosomal hydrolases are treated as secreted proteins and are exported from the cell, rather than taken to the lysosomes. The secreted proteins will have which one of the following effects on the cells and proteins in the circulation?

•  Circulating proteins will be targeted to the spleen for removal.

• There will be no effect on the proteins and cells in the circulation.

• The blood cell membranes will become leaky, leading to the death of the blood cells.

• The blood cells will have their carbohydrates on the cell surface removed.

Multiple Choice

Which of the following pathways occurs in the peroxisome?

• Cyclin degradation

• Glycolysis

• Medium-chain fatty acid β-oxidation

• Ubiquitination

• Very-long-chain fatty acid β-oxidation

Multiple Choice

An 18-month-old girl is brought to the physician because she has a hoarse voice and is unable to roll over or sit unsupported. On physical examination, she is small for her age with club feet, coarse facial features, and enlarged gums. She is diagnosed with a condition caused by an enzymatic defect in N-acetylglucosamine-1-phosphotransferase.

This child’s enzymatic defect occurs in an intracellular organelle that normally performs which of the following functions?

• β-Oxidation of long-chain fatty acids

• Degradation of cellular materials

• Lipid and membrane biosynthesis

• Protein modification