lipids Flashcards
(23 cards)
What do simple lipids consist of?
An alcohol linked to one or more fatty acids via an ester linkage.
What type of reaction occurs when an ester linkage is formed between glycerol and fatty acids?
Condensation reaction.
What is lost during the formation of an ester linkage?
One molecule of water.
What happens to the melting point of fats as hydrocarbon chain length increases?
It increases.
What is the effect of longer hydrocarbon chains on hydrophobic interactions?
They increase the extent of hydrophobic interactions.
What happens to the melting point of fats as the degree of unsaturation of fatty acid tails increases?
It decreases.
Why do double bonds in fatty acid tails affect melting points?
They create kinks that prevent close packing of molecules.
What is hydrophobic interaction?
A weak bond between hydrophobic molecules.
How does the packing of fatty acid tails relate to thermal energy requirements?
Less closely packed tails require less thermal energy to liquefy triglycerides.
What is the structural composition of triglycerides? Relate this to its function.
Triglycerides have a higher proportion of C and H atoms compared to O atoms. Triglycerides contain a greater number of carbon atoms per unit mass than carbohydrates. Triglycerides release a larger amount of energy upon oxidation and are more efficient energy stores than carbohydrates.
This structure contributes to their function as energy stores.
What are triglycerides classified as?
Triglycerides are highly reduced molecules
How do triglycerides compare to carbohydrates in terms of hydrogen atoms?
Triglycerides contain two-fold more hydrogen atoms per unit mass than carbohydrates
What is the function of triglycerides during cellular respiration?
Triglycerides release more water when oxidised during cellular respiration compared to carbohydrates
What is the term for the water released by triglycerides during oxidation?
Metabolic water
What is the significance of triglycerides having no associated water molecules?
They have no extra weight due to the water of hydration
How do triglycerides affect the water potential of cells?
They do not affect water potential when stored in large amounts
What requirement does the absence of water of hydration in triglycerides fulfill?
Keeps an animal’s body mass to a minimum for locomotion
How do the weak hydrophobic interactions in triglycerides relate to its function?
Triglycerides are able to slide under pressure. Adipose tissue surrounds and helps to protect vital organs.
What is the effect of triglycerides having a molecular weight than water?
It is less dense than water and aids buoyancy in aquatic animals.
What is the structure and function of micelles?
a small, spherical droplet
consisting of a phospholipid monolayer, used for the transport of fats between the gut and body tissues
What is the structure and function of the phospholipid bilayer?
two lipid monolayers combine
to form a two-dimensional sheet, form a selectively permeable cell
membrane, acting as an effective barrier / boundary between cell and
its external environment
What is the structure and function of liposomes/vesicles?
formed when a lipid bilayer folds back on itself to form a hollow sphere, creating a separate aqueous compartment. used as vesicles for storage and transport
of cellular products, as well as for
digestion of waste (in lysosomes).
Liposomes also serve as vesicles for drug delivery in humans.
What is the importance of choline in phospholipids?
The most abundant phospholipids in the cell membrane contain choline and thus represent a large proportion of the body’s store of choline. Choline is important for the
synthesis of acetylcholine, a neurotransmitter.
