Podcast
Questions and Answers
Which of the following statements accurately describes lipids?
Which of the following statements accurately describes lipids?
What is a key characteristic of fatty acids?
What is a key characteristic of fatty acids?
Which type of fatty acid has one or more double bonds?
Which type of fatty acid has one or more double bonds?
Which of the following fatty acids is classified as saturated?
Which of the following fatty acids is classified as saturated?
Signup and view all the answers
Why must fatty acids be transported in the blood with proteins like albumin?
Why must fatty acids be transported in the blood with proteins like albumin?
Signup and view all the answers
Which of the following best identifies essential fatty acids?
Which of the following best identifies essential fatty acids?
Signup and view all the answers
What is the carbon count of linoleic acid?
What is the carbon count of linoleic acid?
Signup and view all the answers
What is the primary function of sterol lipids?
What is the primary function of sterol lipids?
Signup and view all the answers
What role does linoleic acid play in human health?
What role does linoleic acid play in human health?
Signup and view all the answers
Which type of lipids are solid at ordinary temperature?
Which type of lipids are solid at ordinary temperature?
Signup and view all the answers
What is the main function of chylomicrons in plasma?
What is the main function of chylomicrons in plasma?
Signup and view all the answers
Which lipoprotein is considered the densest, containing the highest level of protein relative to lipid?
Which lipoprotein is considered the densest, containing the highest level of protein relative to lipid?
Signup and view all the answers
Which type of simple lipid is primarily liquid at room temperature?
Which type of simple lipid is primarily liquid at room temperature?
Signup and view all the answers
What is a primary function of phospholipids in the body?
What is a primary function of phospholipids in the body?
Signup and view all the answers
Which of the following lipoproteins is involved in transferring cholesterol from peripheral tissues to the liver?
Which of the following lipoproteins is involved in transferring cholesterol from peripheral tissues to the liver?
Signup and view all the answers
Study Notes
Lipids
- Organic compounds insoluble in water (hydrophobic)
- Contain carbon, hydrogen, and oxygen, but less oxygen than carbohydrates
- Functions:
- Mechanical protection
- Thermal insulation (under the skin)
- Electrical insulation (around nerves)
- Cell membrane structure
- Steroid hormones
- Energy storage
Fatty Acids
- Monocarboxylic acids (R-COOH) with:
- Hydrocarbon chain (R): hydrophobic
- Carboxyl group (–COOH): ionizes to –COO- (hydrophilic)
- Amphipathic molecules (have both hydrophilic & hydrophobic regions)
- Long-chain fatty acids are highly water-insoluble
- Fatty acids are transported in the blood with a protein (albumin).
- Usually contain an even number of carbon atoms.
Types of Fatty Acids
-
Saturated Fatty Acids: No double bonds
- Butyric acid (4C): CH3 - CH2 - CH2 - COOH (4:0)
- Palmitic acid (16 C): CH3 - (CH2)14 – COOH (16:0)
- Stearic acid (18C): CH3 - (CH2)16 - COOH (18:0)
-
Unsaturated Fatty Acids: One or more double bonds
- Oleic acid (18C): One double bond between C9 & C10.
- Linoleic acid (18 C): Two double bonds between C9 & C10 and C12 & C13.
- Linolenic acid (18 C): Three double bonds between C9-10, C12-13 & C15-16.
Essential Fatty Acids (PUFA)
- Cannot be synthesized in the human body
- Must be supplied with food
- Two essential fatty acids in humans:
- Linoleic acid (w6): Precursor of arachidonic acid, important for prostaglandin synthesis.
- α-Linolenic acid (w3): Precursor for other w3 (omega-3) fatty acids, important for growth, development, and protection from heart problems.
Simple Lipids
- Natural fats or Triacylglycerols (TAG): Esters of 3 fatty acids with the tri-hydroxy alcohol glycerol
- Fats: Solid at room temperature.
- Oils: Liquid at room temperature.
-
Occurrence of neutral fat:
- Found in plants: cottonseed oil, olive oil, palm oil, coconut oil, etc.
- Found in animals: butter.
- Found in marine oils: cod liver oil.
Conjugated Lipids
-
Phospholipids (PL):
- Important for cell membrane structure
- Helps triglyceride absorption in the small intestine
- Lecithin acts as a lipotropic factor
- Lecithin is a component of lung surfactant
- Cardiolipin is used to detect syphilis
- Sphingophospholipids act as electrical insulators (myelin sheath).
-
Glycolipids: Lipids linked to carbohydrates.
-
Plasma Lipoproteins: Spherical macromolecular complexes of lipids and proteins (apoproteins, apolipoproteins)
- Function: Transport lipids in plasma
- Types:
- Chylomicrons: Lowest density & largest size, highest % of lipid & the lowest % of protein.
- VLDLs & LDLs: Denser, with higher ratios of protein to lipid than chylomicrons.
- HDL: The densest, containing the highest level of protein to lipid.
Functions of Plasma Lipoproteins
- Chylomicrons: Carry exogenous dietary lipids (mainly TG) from the intestine to peripheral tissues.
- VLDLs: Carry endogenous lipid (mainly TG) from the liver to extrahepatic tissues.
- LDLs: Transfer cholesterol from blood to tissues (originate from VLDLs in blood).
- HDLs: Take cholesterol from peripheral tissues and transfer it to the liver.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
