Lipids Flashcards
What are lipids?
group of compounds that are insoluble
in water but soluble in ethanol
What are the most common types of lipids?
triglycerides
Whats the major roles of lipids?
energy source
How much more energy does lipids provide than carbohydrates?
Twice more than carbohydrates (38kJ)
How are lipids stored in the tissue ?
What roles does it play?
adipose
heat insulation:in
mammals, adipose tissue
underneath the skin
helps reduce heat loss
protection:around delicate organs such
as the kidneys acts as a cushion against impacts
What are Triglycerides?
type of fat (lipid) found in your blood
What are Triglycerides made up of?
What type of reaction is it
and whats formed ?
Whats the bond called? and how many bonds are formed?
3 fatty acid chains attached to a
glycerol molecule
condensation, 3 fatty acids 3 water molecules are formed.
ester bond, 3 ester bonds
What are esters?
They are characterized by a carbon bound to three other atoms: a single bond to a carbon, a double bond to an oxygen, and a single bond to an oxygen.
Basic difference between saturated and unsaturated fatty acids
Saturated = C–C bonds
Unsaturated = one or more C=C bonds
What are Saturated fatty acids? (4)
Every carbon atom is bonded to as many
hydrogen atoms as possible no more can
be added
Carbon chain is
straight, with no
kink
Triglycerides consisting of saturated fatty
acids can pack together to form solid fat
at room temperature
Mainly found in
animal fats from
meat and dairy
products
What are Unsaturated fatty acids? (4)
Not every carbon atom is bonded to as many hydrogen atoms as it
could be and so there are
double bonds present
Double bonds
introduce a definite
‘kink’ in the carbon
atom chain
Triglycerides consisting of ‘ kinky’ unsaturated
fatty acids do not pack together easily and
form liquid oils at room temperature
Mainly found in
vegetable oils,
nuts and fish
What are phospholipids?
Type of lipids
What are phospholipids made of?
What are their function?
2 fatty acids chains + phosphate head
Fatty acid chains = non-polar = hydrophobic “water fearing”
Phosphate head = polar = hydrophillic “water loving”
make up cell membranes
What happens when we place Phospholipids in water?
The hydrophilic heads face outwards as they are
attracted to water.
The hydrophobic tails are attracted to each other
(forming the inside layer) and a double layer is formed.
Whats the test for lipids?
Whats the result when its positive?
emulsion test
milky emulsion
