Lipids Flashcards
Identify the different types of lipids; discuss the functions of lipids
What are the main elements in lipids?
Carbon, hydrogen and oxygen
What are the seven main types of lipids?
- Fatty acids
- Triglycerides
- Phospholipids
- Steroids
- Eicosanoids
- Fat-soluble vitamins
- Lipoproteins
Which type of lipid is the most plentiful in the body and diet?
Triglycerides
What are the ‘building blocks’ of triglycerides?
1 x glycerol and 3 x fatty acids
In a triglyceride, do all the fatty acids have to be identical?
No, they can even be a mixture of saturated and unsaturated fatty acids
What are the carbon chain lengths of each type of fatty acid:
1. Short chain
2. Medium chain
3. Long chain
- <6
- 6-12
- > 12
What is the distinction between fats and oils?
Fats are solid at room temperature whereas oils are liquid
Why are fats solid at room temperature?
They mostly contain saturated fatty acids which can pack closer together as the lack of double bonds means a lack of ‘kinks’ in the carbon chain
What is the structure of a steroid?
All have four carbon rings and all are based on cholesterol, the ‘originator’ steroid made in the liver
What are the five main types of steroids?
- Cholesterol
- Bile salts
- Vitamin D
- Adrenocortical hormones
- Sex hormones
What are the two key functions of fatty acids in the body?
- Used to make triglycerides and phopholipids
- Broken down to generate ATP
What are the three key functions of triglycerides?
- Protection
- Insulation
- Energy storage
What are the two key functions of cholesterol?
- Minor component of all animal cell membranes
- Precursor of bile salts, vitamin D and steroid hormones
What is the key function of bile salts?
Needed for digestion and absorption of dietary lipids
What are the three key functions of lipoproteins?
- Transport lipids in blood
- Carry triglycerides and cholesterol to tissues
- Remove excess cholesterol from blood
What are eicosanoids?
20-carbon lipids derived from arachidonic acid with hormone-like effects
Name two types of eicosanoids
- Prostaglandins
- Leukotrienes
Give some examples of eicosanoid functions
Modify hormone responses, contribute to inflammation and allergic responses, dilate airways, regulate body temperature and more
What is the function of phospholipids?
Major lipid component of cell membranes
What effect does intake of saturated fats have on blood lipids?
Raising of total cholesterol and low-density lipoproteins (LDLs)
What are the main dietary sources of saturated fat?
Red meats, processed meats, whole-milk dairy products, palm and coconut oils
What effect does intake of monounsaturated fats have on blood lipids?
Lowering of total blood cholesterol and low-density lipoproteins (LDLs)
What are the main dietary sources of monounsaturated fat?
Olive oil, peanut oil, canola oil, avocados, walnuts, sunflower seeds, tofu and soybeans
What are the two main types of polyunsaturated fats?
These fats are essential - they must be consumed (body cant make them)
Omega-3 and omega-6
