What is the order of importance of energy sources?
Carbohydrates, fats, proteins, nucleic acids
What are carbohydrates made of?
C, H, O
what is the role of carbohydrates
transporters of energy
what is the most important carbohydrate
glucose
what forms does glucose exist in
linear-carbonyl group on C1, circular,
what is a monosaccharide and example
simple sugar molecule, glucose
what makes maltose
2 glucose
what makes lactose
glucose and galactose
what makes sucrose
fructose and glucose
what are the common monosacharides?
glucose, fructose, galactose
what are the common disaccharides?
sucrose, maltose, lactose
what are the limits for the levels of glucose within the bloodstream
between 4 and 8mM
what is hypoglycaemic?
blood glucose below 4mM
what is hyperglycaemic?
blood glucose higher than 8mM
how does the body regulate blood glucose levels?
hormones including glucagon, insulin, norepinephrine (adrenaline)
what is diabetes?
lacking ability to synthesis insulin and therefore unable to control blood sugar levels
what are the most common polysaccharides of glucose?
glycogen, starch, cellulose
what is glycogen
energy reservoir stored in skeletal muscle and liver
where is starch found
only in plants
what type of bond does starch contain
alpha 1,4-glycosidic bond
what type of bond does glycogen contain
alpha 1,4- glycosidic linkages and alpha 1,6- linkages forming side branches
what is the importance of the bonds in glycogen
maximises the number of ends available for digestion by enzymes that catalyse the breakdown of glycogen, more free ends=faster synthesis/break down
what is the difference in cellulose bonds
it uses beta 1,4- glycosidic linkages which humans are unable to break down
what is fibre
cellulose, unable to be digested and is inert as an energy source
what is the isomer of glucose and how does it differ
fructose, carbonyl group on carbon 2
what is an epimer of glucose and how does it differ
galactose, identical except for H and OH groups on C4 rotates 180 degrees
what is the difference in energy released by the monosaccharides glucose, fructose and galactose
none only the pathways differ
when does the body use fats for energy
when the supply of glucose decreases due to dieting, starvation or extended period between eating
what are lipids/fats composed of?
C, H, O
what is an example of a free fatty acid?
palmitic acid
how is palmitic acid composed
16 carbons with a carboxyl group at one end with a long hydrocarbon chain
what is a saturated fatty acid
fatty acid chain with no double bonds- all carbons are saturated with hydrogen atoms
what is an unsaturated fatty acid
contains at least one double bond
what is the notation for palmitic acid
16:0
what would 24:3 mean when describing fatty acids
24 carbons long and 3 double bonds
what form do the fats in membranes exist as
diglyceride or diacylglycerol
what are acyl groups
fatty acids chains
what is glycerol
three carbon sugar possessing three alcohol groups
what is a monacylglycerol/monoglyceride
one fatty acid joined to a glycerol molecule
where are triglycerides found
fat storage cells- adipocytes that make up adipose tissue
what are lipids
hydrophobic molecules
what do lipids include
fats, oils, waxes
what is the difference between fats, oils and waxes
composition of the molecules and degree of saturation
what type of fatty acid is more likely to pack together
saturated
what is butter composed of
saturated fatty acids
what is vegetable oil composed of
unsaturated fatty acids
what are fatty acids oxidised/broken down to
carbon dioxide and water and energy
why are fatty acids an efficient form of storing energy
molecule is highly reduced, light-less dense than water, hydrophobic- doesn't need to be dissolved in water for storage, completely oxidised to form Co2 doesn't form toxic products
what are steroids
lipids that are formed from four or five ring structures