Signaling Lipids/Energy Storage Flashcards
What is the structure of a steroid?
Four cycloalkane rings fused together
(3 cyclohexanes and 1 cyclopentane)
What is the function of the steroid, cholesterol?
Maintains cell membrane fluidity and synthesizes ALL steroids.
(Cholesterol is amphipathic.)
What effect does cholesterol have on membrane fluidity in eukaryotic cells at high temperatures?
High temperatures = decreases fluidity
What effect does cholesterol have on membrane fluidity in eukaryotic cells at low temperatures?
Low temperatures = increases fluidity
What are the four fat-soluble vitamins?
- Vitamin A (carotene/vision)
- Vitamin D (regulates calcium)
- Vitamin E (antioxidants)
- Vitamin K (posttranslational modifications for coagulation)
[Mnemonic]
FAT cat is in the “attic” or “ADEK”.
(how to remember the fat-soluble vitamins)
FAT cat is in the “attic” or “ADEK”.
The fat soluble vitamins are A, D, E, and K.
[Mnemonic]
Vitamin K is for Koagulation.
(how to remember the function of vitamin K)
Vitamin K is for Koagulation.
Vitamin K forms blood clots (coagulation).
Which class of lipids are the precursors to steroids and other signaling lipids?
Terpenes
What are terpenes composed of?
2 or more isoprene units (C5H8)
What is the function of prostaglandins?
Regulate the synthesis of cAMP, which is involved in many pathways.
What is the difference between the storage of fat-soluble vitamins and water-soluble vitamins?
Fat-soluble vitamins: stored in the body
Water-soluble vitamins: excreted through the urine
What is the composition of the storage lipids triglycerides (triacylglycerols)?
3 fatty acid tails connected to a glycerol backbone via ester linkages.
What is a saponification reaction?
Making “soap”
(The ester hydrolysis of triacylglycerols using a strong base.)
