1.3 Lipids Flashcards
Why do fats form good waterproofing layers?
lipid tail is hydrophobic so they are insoluble in water
What is a structure of a triglyceride?
1 glycerol and 3 fatty acid tails
What chemical group does glycerol belong to?
alcohol
What are the two different types of fatty acids?
saturated or unsaturated
What bond forms between a fatty acid and glycerol in a triglyceride?
esther bond
What type of reaction happens when esther bonds form?
condensation
What test is used to idenify lipids?
the emulsion test
How is the emulsion test carried out?
take equal vol of water and ethanol with food sample
shake
a cloudy white emulsion will form if lipid present
What part of the phosphlipid is non-polar?
fatty acid tails
What is a respiratory substrate?
any molecule that can be released as energy to create ATP
How do animals get energy from a resp substrate?
energy is released by breaking the C-C bonds and C-H bonds
Why do lipids store more chemical potential energy than carbs?
lipids have more C-C and C-H bonds due to the hydrocarbon tail
What elements are present in lipids?
carbon, hydrogen, oxygen
Are lipids soluble in water? if no what are they soluble in?
no, soluble in organic solutes like ethanol
What are some examples of lipids?
triglycerides - fats and oils
waxes
steroids
cholesterol
What are all the functions of lipids?
thermal insulation
cell membrane structure
energy store
waterproof
source of metabolic water
buoyancy
protection
How are lipids good for insulation?
fats are slow conductors of heat
stored underneath the body surface to help retain body heat
eg: adipose tissue
What is adipose tissue?
a connective tissue that extends throughout your body - body fat
found under the skin
What properties of lipids make is a good energy store?
compact - can store more in small space
insoluble - osmotically inert
high energy yeild - x2 the energy released than carbs when oxidised