1.2 Lipids Flashcards
What does amphipathic mean?
A molecule which has both hydrophilic and hydrophobic parts
What is an ester bond?
A type of bond formed in a condensation reaction that joins each of the fatty acid tails to the glycerol molecule in a triglyceride
What is a fatty acid?
A long chain molecule which is composed of a carboxylic (COOH) group and may contain C=C double bonds
What is glycerol?
A 3 carbon molecule which contains 3 hydroxy (OH) groups and is a component of a triglyceride
What is a phospholipid and where would it be found?
It is a type of amphiphatic lipid based on a triglyceride but where one of the fatty acid tails is replaced with a negative phosphate group, and is found as a component of the phospholipid bilayer in cell membranes
What is a saturated lipid?
A lipid molecule containing only single bonds between it’s carbon atoms
What is an unsaturated lipid?
A lipid molecule which contains at least one double bond between it’s carbon atoms
What is a triglyceride?
A lipid macromolecule composed of one molecule of glycerol joined by ester bonds to 3 fatty acid tails
Where are saturated and unsaturated lipids each found?
Saturated lipids are found in animal fats and unsaturated lipids are found in plants
What are the 2 differences between saturated and unsaturated lipids and why do they occur?
Saturated lipids are solid at room temperature whereas unsaturated lipids are liquid. This is because the intermolecular forces between unsaturated lipids are weaker so they therefore have lower melting points. Saturated lipids are also more compact than unsaturated lipids as they have no kinks in their carbon chains so can fit closer together
Why are lipids waterproof?
As their fatty acid tails are hydrophobic
Why do lipids have a better gram-for-gram energy release than carbohydrates and proteins
As they have more C-O bonds to be hydrolysed
Why are lipids good for storage?
As they are non-polar and insoluble in water, so they don’t interfere with the water-based reactions in the ctyoplasm
Why are lipids good as thermal insulators?
As they conduct heat slowly
