Concept explainers
To explain: The group that has the highest LDL-to-HDL ratio.
Concept introduction: Lipoproteins are carriers of hydrophobic molecules, in the extracellular matrix and the blood. They are made of phospholipids, cholesterol, and proteins. Proteins are made of amino acids. Low density lipoprotein (LDL) transports fat, essentially cholesterol molecules, in an aqueous medium. LDL can get oxidized with arterial walls and form plaque. HDL carries cholesterol to the liver for breaking it down to simple forms, where it is converted into bile acids and sent to the intestine for excretion. Fatty acids (or cis-unsaturated fatty acids or fat) are fatty acids that have carbon-carbon double bonds with cis configuration. Trans fatty acids (or trans-unsaturated fatty acids or trans fats) are fatty acids that have carbon-carbon double bonds with trans configuration. Trans fats have unusual trans configuration. Saturated fatty acids have fatty acid chains lacking double bonds between their carbon atoms.
Want to see the full answer?
Check out a sample textbook solutionChapter 3 Solutions
MindTap Biology, 1 term (6 months) Printed Access Card for Starr/Taggart/Evers/Starr's Biology: The Unity and Diversity of Life (MindTap Course List)
- Effects of Dietary Fats on Lipoprotein Levels Cholesterol that is made by the liver or that enters the body from food does not dissolve in blood, so it is carried through the bloodstream by lipoproteins. Low-density lipoprotein (LDL) carries cholesterol to body tissues such as artery walls, where it can form deposits associated with cardiovascular disease. Thus, LDL is often called bad cholesterol. Highdensity lipoprotein (HDL) carries cholesterol away from tissues to the liver for disposal, so HDL is often called good cholesterol. In 1990, Ronald Mensink and Martijn Katan published a study that tested the effects of different dietary fats on blood lipoprotein levels. Their results are shown in Figure 2.23. In which group was the level of LDL (bad cholesterol) highest?arrow_forwardEffects of Dietary Fats on Lipoprotein Levels Cholesterol that is made by the liver or that enters the body from food does not dissolve in blood, so it is carried through the bloodstream by lipoproteins. Low-density lipoprotein (LDL) carries cholesterol to body tissues such as artery walls, where it can form deposits associated with cardiovascular disease. Thus, LDL is often called bad cholesterol. Highdensity lipoprotein (HDL) carries cholesterol away from tissues to the liver for disposal, so HDL is often called good cholesterol. In 1990, Ronald Mensink and Martijn Katan published a study that tested the effects of different dietary fats on blood lipoprotein levels. Their results are shown in Figure 2.23. Figure 2.23 Effect of diet on lipoprotein levels. Researchers placed 59 men and women on a diet in which 10 percent of their daily energy intake consisted of cis fatty acids, trans fatty acids, or saturated fats. Blood LDL and HDL levels were measured after three weeks on the diet; averaged results are shown in mg/dL (milligrams per deciliter of blood). All subjects were tested on each of the diets. The ratio of LDL to HDL is also shown. Source, Mensink RP, Katan MB, Effect of dietary trans fatty acids on high-density and low-density lipoprotein cholesterol levels in healthy subjects. NEJM 323(7):43945. An elevated risk of heart disease has been correlated with increasing LDL-to-HDL ratios. Rank the three diets according to their predicted effect on cardiovascular health.arrow_forwardLipoproteins are relatively large, combined clumps of both protein and lipid molecules that circulate in the blood of mammals. They come in two forms, called HDL and LDL, and they act like suitcases to move cholesterol, fatty acid remnants, triglycerides, and phospholipids from one place to another through the bloodstream. (LDL recirculates lipids throughout the body, while HDL takes lipids to the liver to excrete them in feces.) Given that lipids are hydrophobic and proteins can be hydrophilic, which of the following statements is correct? (a) The lipid portion of LDL does not dissolve in the bloodstream, while the lipid portion of HDL does. (b) The protein portions of both LDL and HDL can dissolve or interact with the water molecules in the bloodstream. (c) Neither the protein nor the lipid portions of LDL molecules can interact with water molecules in the bloodstream. (d) Both the protein and the lipid portions of HDL molecules can interact with water molecules in the bloodstream.…arrow_forward
- Which of the following statements regarding trans fatty acids is FALSE? Trans fatty acids increase the shelf-life of processed foods. Trans fatty acids were saturated fatty acids prior to hydrogenation. A diet that is rich in trans fatty acids increases the risk of heart disease, and therefore trans fatty acids in foods must be labeled. Trans fatty acids are a byproduct of hydrogenating fats.arrow_forwardDo we have good and bad cholesterol? What happens when the density of LDL in the blood increases while the density of HDL decreases?arrow_forwardAll lipoproteins are made up of proteins, triglycerides, and cholesterol. Why are low-density lipoproteins (LDL) considered unhealthy, and people are encouraged to lower LDL, while high-density lipoproteins (HDL) are considered healthy, and people are encouraged to increase HDL? What are some good ways to lower LDL and raise HDL levels in the human body?arrow_forward
- Fats and oils are both triglycerides. Which description(s) below are true regarding the difference(s) between fats and oils? Fats and oils are both triglycerides. Which description(s) below are true regarding the difference(s) between fats and oils? Steroid All statements are true except A. Fats are solid at room temperature because they are saturated triglycerides. Fats are produced by animals and oils by plants. Oils are liquid at room temperature because they are unsaturated triglycerides. Fats and oils have the same properties and characteristics and are not different from one another.arrow_forwardFatty acids are a component of fats but have distinct chemical difference apart from fats that would allow them to travel fairly freely in the aqueous environment of the blood stream. They don’t, however, and are transported with serum albumin. What about the chemistry of fatty acids makes it so that it might not be good to have a lot of them traveling freely in the bloodstream?arrow_forwardWhich of the following is a source of essential fatty acids that the body cannot produce on its own? a) Saturated fats b) Trans fats c) Monounsaturated fats d) Omega-3 and Omega-6 fatty acidsarrow_forward
- Among the many eat-all-you-want-and-lose-weight diets that have been popular for a time is one that eliminates all carbohydrates but permits the consumption of all the protein and fat desired. Would such a diet be effective?arrow_forwardWhich of the following is not an example of a protein? a) Hemoglobin b) Keratin c) Insulin d) Chitinarrow_forwardIn dietary context, what is the difference between good and bad cholesterol? In dietary context, how do HDL and LDL differ in function?arrow_forward
- Biology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage LearningBiology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage Learning