Lipids + fatty acids Flashcards
Why are lipids insoluble in water + why, and what are they soluble in
Hydrophobic–> consist hydrocarbons that form non-polar covalent bonds
soluble in organic solvents
what are fatty acids used for
broken down to generate ATP
synthesise triglycerides + phospholipids
what are triglycerides used for
energy storage
protection
insulation
where are phospholipids found
in plasma membrane
what are steroids used for
cholesterol + hormone components
what is a fatty acid
long hydrocarbon chain with carboxylate group
what is saturated fatty acid
NO DOUBLE BOND between carbons
solid –> hydrocarbon chain is straight so pack more tight together
what is a unsaturated fatty acid
AT LEAST 1 double bonds between carbons
what is cis unsaturated fatty acid
carbon atoms in double bond have H atom on same side of double bond
natural
what is trans unsaturated fatty acid
carbon atoms in double bond have H atom on opposite side of double bond
describe the characteristics of palmitic acid
hydrophobic
non-polar hydrocarbon chain
hydrophilic negative charged carboxylic group – associates with water
saturated
describe the characteristics of oleic acid
monounsaturated
kink in chain = rigid so cannot rotate
can’t pack tightly together
liquid at room temp
what is triglyceride made of
3 fatty acids
1 glycerol
what are triglycerides used for
energy source
globular –> good storage
transport of lipids
what are adipocytes + why are they important for triglycerides
synthesis + storage of triglycerides
adipocytes found in subcutaneous layer in abdominal cavity
what are phospholipids made of
1 glycerol
2 fatty acids
1 phosphate group
why are phospholipids called amphipathic
fatty acid tail = hydrophobic
phosphate head = hydrophilic
how much of cell membrane is made of phospholipids
50% - in bilayer
how much of cell membrane is made of cholesterol + what is it used for
20%
membrane less flexible
reduces permeability of membrane
what are glycolipids made of
2 long hydrophobic hydrocarbon tails
1 or more polar sugar
how much of cell membrane is made of glycolipids + what is their function
5%
protect + control function of membrane
where else are glycolipids used in different cells
insulating agent in nerve cells
what are steroids made up of + 1 example of steroid
4 carbon rings
Cholesterol
what hormones are synthesised from cholesterol
testosterone
oestrogen
cortisol
why are lipoproteins used in the body
lipids are insoluble in water so transported in plasma as lipoproteins
lipoprotein carries fatty acid in blood + around body to cells
what are apoproteins
protein component of lipoproteins
they interact with cellular receptors + determine metabolic rate of lipoprotein
what are essential fatty acids
needed in human diet but can’t be synthesised so must come from food
what are examples of essential fatty acids + where can they be obtained
alpha linoleic acid + linoleic acid in forms of omega 3 + 6
oily fish, rapeseed oil + leafy vegetables
what are symptoms of deficiency in essential fatty acids
dry scaly rash
decreased growth
poor immunity + wound healing
what is lipolysis + what happens after it + where does it occur
breakdown of triglycerides into glycerol + fatty acids + release of energy
free fatty acids released into blood + circulate the body
muscle liver + adipose tissue to produce ATP
how does lipolysis breakdown a triglyceride
hydrolysed into glycerol + 3 fatty acids
using water + lipase
how is lipolysis used to break down glycerol + fatty acids
glycerol –> glucose + enters glycolysis to make ATP
fatty acids –> acetyl coA + enters Krebs cycle
what is lipogenesis + where does it occur
synthesis of lipids
liver + adipose tissue
how is excess glucose linked to lipogenesis
excess glucose –> glycogen + triglycerides
in muscle + liver
how is fructose linked to lipogenesis
fructose –> glycogen + triglycerides
by liver
linked to obesity
