Podcast
Questions and Answers
The presence of many C-C and C-H bonds causes fats to be...
The presence of many C-C and C-H bonds causes fats to be...
The highlighted part of this molecule is derived from...
The highlighted part of this molecule is derived from...
In fat synthesis, ________ and fatty acids combine to make fats plus ________.
In fat synthesis, ________ and fatty acids combine to make fats plus ________.
In the reaction that builds a fat, ________ groups react with ________ groups.
In the reaction that builds a fat, ________ groups react with ________ groups.
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Triglycerides vary with respect to the number of...
Triglycerides vary with respect to the number of...
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A food company hydrogenated a barrel of fat. The treatment...
A food company hydrogenated a barrel of fat. The treatment...
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The most unsaturated fats have...
The most unsaturated fats have...
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What do DNA, proteins, and fats have in common?
What do DNA, proteins, and fats have in common?
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Which statement most accurately explains why cholesterol and phospholipids are amphipathic but fats are not?
Which statement most accurately explains why cholesterol and phospholipids are amphipathic but fats are not?
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A phospholipid is a _____
A phospholipid is a _____
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What region of a steroid is hydrophilic?
What region of a steroid is hydrophilic?
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Phospholipids and triglycerides both _____
Phospholipids and triglycerides both _____
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Lipids _____
Lipids _____
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Steroids are considered to be lipids because they _____
Steroids are considered to be lipids because they _____
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Molecules that are amphipathic must contain _____
Molecules that are amphipathic must contain _____
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Lipids are insoluble in water because _____
Lipids are insoluble in water because _____
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Which of the following is true of membrane lipids?
Which of the following is true of membrane lipids?
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In an experiment involving planar bilayers, what can you conclude if the right side tests negative for ions?
In an experiment involving planar bilayers, what can you conclude if the right side tests negative for ions?
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Which aspect of phospholipids is most important to the formation of bilayers?
Which aspect of phospholipids is most important to the formation of bilayers?
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Which of the following increases the strength of hydrophobic interactions in lipid bilayers?
Which of the following increases the strength of hydrophobic interactions in lipid bilayers?
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Which of the following crosses lipid bilayers the fastest?
Which of the following crosses lipid bilayers the fastest?
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Which of the following crosses lipid bilayers the slowest?
Which of the following crosses lipid bilayers the slowest?
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Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
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Decreasing the saturation of the fatty acid chains on a particular type of phospholipid would result in the formation of _____
Decreasing the saturation of the fatty acid chains on a particular type of phospholipid would result in the formation of _____
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Which term best describes the type of membrane protein in the figure?
Which term best describes the type of membrane protein in the figure?
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For the study shown in the figure, what is the most appropriate control?
For the study shown in the figure, what is the most appropriate control?
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Where would you most likely find an integral membrane protein?
Where would you most likely find an integral membrane protein?
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When biological membranes are frozen and then fractured, they tend to break along the middle of the bilayer. The best explanation for this is that _____
When biological membranes are frozen and then fractured, they tend to break along the middle of the bilayer. The best explanation for this is that _____
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When a membrane is freeze-fractured, the bumps seen on the fractured surface of the membrane are _____
When a membrane is freeze-fractured, the bumps seen on the fractured surface of the membrane are _____
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Study Notes
Lipids Overview
- Fats are rich in energy due to numerous C-C and C-H bonds and are insoluble in water.
- Phospholipids feature a hydrophilic head and a hydrophobic tail, making them amphipathic.
Fatty Acids and Glycerol
- Glycerol is derived from fatty acids, which are key components in fat synthesis where glycerol and fatty acids yield fats and water.
- Fats are formed through the reaction of hydroxyl and carboxyl groups.
Triglycerides
- Triglycerides differ in the number of carbon atoms and the presence of double bonds in their hydrocarbon tails.
Hydrogenation
- Hydrogenation of fats results in decreased fluidity and higher saturation levels, affecting the structure of fatty acid tails.
Unsaturated Fats
- The most unsaturated fats possess the highest number of double bonds, impacting their properties.
Common Features of Macromolecules
- DNA, proteins, and fats contain carbonyl groups, representing a shared molecular feature.
Amphipathic Molecules
- Cholesterol and phospholipids are amphipathic due to their dual hydrophilic and hydrophobic regions, unlike fats which are primarily hydrophobic.
- Molecules must contain both hydrophilic and hydrophobic regions to be classified as amphipathic.
Solubility and Permeability
- Lipids, including steroids, are characterized by their insolubility in water due to their nonpolar bonds.
- Membrane lipids are amphipathic, allowing for the formation of bilayers that regulate permeability to substances.
Membrane Structure
- Short, saturated hydrocarbon tails in phospholipids lead to less permeable membranes, counteracting the effects of tail length on permeability.
- When phospholipids and water are mixed, tiny vesicles filled with water may form upon mechanical shaking.
- Ions cannot cross planar bilayers, confirming the selective permeability of membranes.
Membrane Proteins
- Integral membrane proteins span across the bilayer, with portions exposed inside and outside the cell, contributing to membrane stability and function.
- Freeze-fracture studies reveal structural aspects of membranes, with bumps indicating the presence of integral proteins.
Molecular Movement
- Small nonpolar molecules, like oxygen (O2), pass through lipid bilayers rapidly, while ions such as sodium move across the bilayer slowly.
- The permeability of bilayers can be influenced by the saturation of fatty acid chains, with more fluid bilayers resulting from decreased saturation.
Experimental Controls
- In studies involving membrane properties, using a pure phospholipid artificial membrane can help isolate effects from experimental artifacts, confirming observed phenomena are attributable to lipid behavior.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on lipids with these flashcards from Chapter 6 of Mastering Biology. Each card presents key concepts related to fats, glycerol, and their properties. Perfect for quick review and better retention of important biological terms.
