Practice Exam 2 Flashcards

(32 cards)

1
Q

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

A

Phospholipid

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2
Q

What is the role of cholesterol in animal cell membranes

A

Enhances membrane fluidity by disrupting intermolecular forces between fatty acid chains at low T and decrease fluidity at high Ts.

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3
Q

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

A

It is an integral protein

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4
Q

Which does NOT apply to the diffusion of O2, CO2, and small hydrophobic molecules across a membrane

A

The transport is facilitated by the Na+/K+ pump

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5
Q

Which of the following is the slowest movement of lipids in biological membranes

A

Transmembrane Diffusion
Flip-Flop

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6
Q

Which of the following best describes what happens to entropy of a particular molecule as the number of resonance structures increases

A

Entropy is increased

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7
Q

Which of the following types of proteins pass through both leaflets of the membrane

A

Integral membrane protein

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8
Q

What kind of facilitated cotransport can move some substrate across a membrane against its concentration gradient

A

Active

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9
Q

Is this true or false
Lipids and proteins move laterally at approximately the same rate within the membrane

A

False

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10
Q

What enzyme is activated by association with an active G protein

A

Adenylate Cyclase

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11
Q

A small molecule produced inside a cell in response to a hormone binding to its receptor is called what

A

secondary messenger

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12
Q

When cyclic Amp is a second messenger what happens

A

The binding of hormone produces the desired effect in the cell by stimulating the production of cyclic AMP

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13
Q

PFK catalyzes what and is inhibited by what and stimulated by what

A

F6P to FBP, ATP, AMP

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14
Q

Metabolic steps are usually regulated at

A

A step where there is a large negative delta G for conversion of reactants to products

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15
Q

In gluconeogensis, the net gain of ATP is what and the net gain of GTP is

A

-4, -2

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16
Q

Hexokinase is an example of what kind of enzyme

17
Q

Which of the following factors contributes to the highly exergonic nature of AcetylCoA hydrolysis

A

The high potential energy thioester bond

18
Q

A molecule that is considered a good fuel is one that is

A

In the most reduced state possible such as a saturated hydrocarbon

19
Q

Reasons for having high-phosphoryl-transfer potential

A

Reduction of charge repulsion
Increase in entropy
Increase in resonance stabilization.

20
Q

In general, catabolism is what

A

An oxidative process that releases energy

21
Q

Bile salts are derivatives of

22
Q

Which substance is a product of glycolysis, a precursor of gluconeogeneis and a precursor of the citric acid cycle

23
Q

Which of the following factors contribute to the highly exergonic nature of ATP hydrolysis

A

Decrease in negative-ion repulsion in ATP

24
Q

Which of the following enzymes requires ATP as a substrate

A

Phosphofructokinase

25
Triose Phosphate Isomerase catalyzes a reaction that is most similar to
Phosphoglucose Isomerase
26
The enzyme pyruvate carboxylase
Requires biotin for activity
27
High concentrations of Fructose-2,6-Bisphosphate stimulate and inhibits what
Stimulate glycolysis Inhibit gluconeogenesis
28
Under anaerobic conditions in skeletal muscle, pyruvate is converted into
Lactate
29
Spingomyelin contains a fatty acid linked by what bond and phosphocholine linked via teh C-3 hydroxyl group of sphingosine
Amide
30
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
31
Trans fatty acids have physical properties like those of
Saturated Fatty Acids
32
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