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Nutrition: Lipids

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Terms in this set (20)

  • What are lipids?

    Lipids are a group of organic compounds that are insoluble in water but soluble in organic solvents. They include fats, oils, phospholipids, and sterols.

  • What is the primary function of lipids in the body?

    Lipids provide energy storage, insulation, protection of organs, and are essential components of cell membranes.

  • Name the three main types of lipids found in the diet.

    Triglycerides, phospholipids, and sterols.

  • What is a triglyceride composed of?

    A triglyceride consists of one glycerol molecule bonded to three fatty acid chains.

  • What distinguishes saturated from unsaturated fatty acids?

    Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.

  • What are essential fatty acids?

    Fatty acids that the body cannot synthesize and must be obtained from the diet, such as linoleic acid and alpha-linolenic acid.

  • What role do phospholipids play in the body?

    Phospholipids are key components of cell membranes and help in the transport of lipids in the bloodstream.

  • What is cholesterol and why is it important?

    Cholesterol is a sterol important for cell membrane structure, hormone synthesis, and vitamin D production.

  • How are lipids digested and absorbed?

    Lipids are emulsified by bile salts, broken down by pancreatic lipase into fatty acids and monoglycerides, then absorbed in the small intestine.

  • What is the energy yield of lipids compared to carbohydrates?

    Lipids provide about 9 kcal/g, which is more than double the energy from carbohydrates or proteins (4 kcal/g).

  • What is the difference between cis and trans fatty acids?

    Cis fatty acids have hydrogen atoms on the same side of the double bond, causing a bend; trans fatty acids have hydrogens on opposite sides, making them straighter.

  • Why are trans fats considered unhealthy?

    Trans fats raise LDL cholesterol and lower HDL cholesterol, increasing the risk of heart disease.

  • What is the role of lipoproteins?

    Lipoproteins transport lipids through the bloodstream to tissues and organs.

  • Name the four main classes of lipoproteins.

    Chylomicrons, very low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL).

  • What is the function of HDL cholesterol?

    HDL removes excess cholesterol from tissues and transports it to the liver for excretion.

  • What is the function of LDL cholesterol?

    LDL delivers cholesterol to cells but high levels can lead to plaque buildup in arteries.

  • What is the chemical formula general for fatty acids?

    Fatty acids have the general formula \(\mathrm{CH_3-(CH_2)_n-COOH}\).

  • What is hydrogenation of fats?

    Hydrogenation is the process of adding hydrogen to unsaturated fats to make them more saturated and solid at room temperature.

  • What are omega-3 fatty acids important for?

    Omega-3 fatty acids support heart health, reduce inflammation, and are important for brain function.

  • What is the difference between fats and oils?

    Fats are typically solid at room temperature, while oils are liquid, due to differences in saturation.