Chapter 11: Lipids (Test 1) Flashcards
What are lipids?
- Molecules that are not soluble in water, but are in organic solvents
What are the five classes of lipids?
- Free fatty acids
- Triacylglycerols
- Phospholipids
- Glycolipids
- Steroids
Free fatty acids
- A common fuel
- Oxidized to make ATP
Triacylglycerols
- The storage form of fatty acids
Phospholipids
- Membrane lipids
Glycolipids
- Membrane lipids composed in part of carbs
- The carb components are on the extracellular side for cell-cell recognition
Steroids
- Polycyclic hydrocarbons with a variety of functions
Saturated
- No double or triple bonds
Unsaturated
- Contains double or triple bonds
At physiological pH, fatty acids are referred to as their___ form
- Carboxylate
When double bonds are present, they are commonly in the ___ config
- Cis
The properties of fatty acids are dependent on?
- Chain length
- Degree of unsaturation
What increases the fluidity of fatty acids?
- Short chain length
- The presence of cis double bonds
What type of fatty acids are precursors to a variety of hormones and appear to offer some protection from coronary heart disease?
- Cis polyunsaturated fatty acids
What is saponification?
- The creation of soaps treatment of triacylglycerols with a strong base
Where in the major site of triacylglycerol storage?
- Adipose tissue (inside a large lipid droplet)
Triacylglycerols contain more than ___ times the energy of a gram of glycogen
- 6
What are the common types of membrane lipids?
- Phospholipids
- Glycolipids
- Cholesterol
What is the major class of membrane lipids?
- Phospholipids
What are the simplest glycolipids?
- Cerebrosides
What is the most common steroid?
- Cholersterol
Sphingolipids
- Contain a sphingosphine backbone
- Found in plants and animals
- Abundant in the nervous system
Where are glycolipids derived from?
- Ceramides
Androgens
- Male sex hormones
- Synthesized in the testes
- Responsible for secondary male sex characteristics
- Testosterone
Estrogen
- Female sex hormones
- Synthesized in the ovaries
- Responsible for secondary female sex characteristics
What does cholesterol do for cells?
- Reduce fluidity
Vitamin A (retinol)
- Serves as the site of the primary photochemical reaction in vision
- Active form is retinal
Vitamin D
- Regulates calcium (and phosphorus) metabolism
- Most abundant form is vitamin D3 in the circulatory system
Vitamin E
- Serves as an antioxidant
Vitamin K
- Has a regulatory function in blood clotting
Prostaglandins
- Have biological effects (e.g. promote inflammation)
Thromboxane A2
- Produced by platelets
- Stimulate blood vessel contriction
- Coagulation
Prostacyclin
- Reverse effects of Thromboxane A2