Practice Exam 2 Flashcards
Liposomes consists of what type of bilayer that encloses an aqueous compartment where drugs can be contained for delivery to specific tissues if target proteins are present
Phospholipid
What is the role of cholesterol in animal cell membranes
Enhances membrane fluidity by disrupting intermolecular forces between fatty acid chains at low T and decrease fluidity at high Ts.
Determination of the tertiary structure of a membrane protein finds that the outer surface is composed primarily of hydrophobic residues. Which conclusion is most likely from this observation
It is an integral protein
Which does NOT apply to the diffusion of O2, CO2, and small hydrophobic molecules across a membrane
The transport is facilitated by the Na+/K+ pump
Which of the following is the slowest movement of lipids in biological membranes
Transmembrane Diffusion
Flip-Flop
Which of the following best describes what happens to entropy of a particular molecule as the number of resonance structures increases
Entropy is increased
Which of the following types of proteins pass through both leaflets of the membrane
Integral membrane protein
What kind of facilitated cotransport can move some substrate across a membrane against its concentration gradient
Active
Is this true or false
Lipids and proteins move laterally at approximately the same rate within the membrane
False
What enzyme is activated by association with an active G protein
Adenylate Cyclase
A small molecule produced inside a cell in response to a hormone binding to its receptor is called what
secondary messenger
When cyclic Amp is a second messenger what happens
The binding of hormone produces the desired effect in the cell by stimulating the production of cyclic AMP
PFK catalyzes what and is inhibited by what and stimulated by what
F6P to FBP, ATP, AMP
Metabolic steps are usually regulated at
A step where there is a large negative delta G for conversion of reactants to products
In gluconeogensis, the net gain of ATP is what and the net gain of GTP is
-4, -2
Hexokinase is an example of what kind of enzyme
Transferase
Which of the following factors contributes to the highly exergonic nature of AcetylCoA hydrolysis
The high potential energy thioester bond
A molecule that is considered a good fuel is one that is
In the most reduced state possible such as a saturated hydrocarbon
Reasons for having high-phosphoryl-transfer potential
Reduction of charge repulsion
Increase in entropy
Increase in resonance stabilization.
In general, catabolism is what
An oxidative process that releases energy
Bile salts are derivatives of
Cholesterol
Which substance is a product of glycolysis, a precursor of gluconeogeneis and a precursor of the citric acid cycle
Pyruvate
Which of the following factors contribute to the highly exergonic nature of ATP hydrolysis
Decrease in negative-ion repulsion in ATP
Which of the following enzymes requires ATP as a substrate
Phosphofructokinase
Triose Phosphate Isomerase catalyzes a reaction that is most similar to
Phosphoglucose Isomerase
The enzyme pyruvate carboxylase
Requires biotin for activity
High concentrations of Fructose-2,6-Bisphosphate stimulate and inhibits what
Stimulate glycolysis
Inhibit gluconeogenesis
Under anaerobic conditions in skeletal muscle, pyruvate is converted into
Lactate
Spingomyelin contains a fatty acid linked by what bond and phosphocholine linked via teh C-3 hydroxyl group of sphingosine
Amide
In an aqueous environment the hydrocarbon tails of lipids tend to associate by entropy-driven what effects and by Van der Waals interactions
Hydrophobic Effect
Trans fatty acids have physical properties like those of
Saturated Fatty Acids
Carriers of an Acyl Group
ATP: 3 Phosphate groups, 3 Rings
CoA: 2 Phosphate group, 3 Rings
FAD: 2 Phosphate group, 6 Rings
NAD+: 2 Phosphate group, 5 Rings
