Carbs and lipids Flashcards
Monomer definition
-small identical molecules
-which can be condensed to make larger polymers called polymers
-via a condensation reaction
Polymers definition
-large molecules
made from joining many identical monomers together
-via a condensation reaction
condensation reaction definition
removal of a water molecule
hydrolysis reaction
addition of water molecule
draw alpha-glucose
-6 carbons
-12 hydrogens
-6 oxygens
-OH are parallel
draw beta-glucose
-6 carbons
-12 hydrogens
-6 oxygens
-OH are diagonal
name the bond between glucose molecules
glycosidic bond
Monosaccharide examples
glucose, fructose, galactose
Disaccharide examples
maltose, sucrose, lactose
Polysaccharides examples
glycogen, starch, cellulose
Glycogen
-only found in animals
-alpha glucose
-shorter chains SO more readily hydrolysed into glucose
-highly branched
-larger surface area
-stored in muscle and liver
-insoluble SO does not affect water potential
amylose properties and benefits
-carbon 1:4 glycosidic bonds SO long and linear chains of alpha glucose with coil into a helix
-compact SO good for storage
-insoluble SO does not affect water potential
-large SO does not diffuse out of cell
amylopectin
-branches chain of alpha glucose
-carbon 1:4 and 1:6 glycosidic bonds
-provides a large surface area FOR rapid hydrolysis by enzymes to release glucose for respiration
-insoluble SO does not affect water potential
-large SO does not diffuse out of cells
-insoluble so do
cellulose
-only found in plants
-beta glucose
-what the cell wall is made out of
-B-glucose molecules join together via condensation reactions to form long unbranched chains
-every other b-glucose molecule rotates 180 degrees to allow carbon 1 and 4 to be adjacent to form a GLYCOSIDIC BOND
-several chains are joined via weak hydrogen bonds to form microfibrils
microfibrils
-wound together to form cellulose fibres
-provides strength and support to plant cells and cell walls are made out of cellulose
Benedict’s test for REDUCING SUGAR
glucose, galactose, lactose, maltose, fructose
-equal amounts of Benedict’s solution to sample
-heat to 95 degrees
-change from blue to red precipitate shows reducing sugar is present
Benedict’s test for NON REDUCING SUGAR
sucrose
-test using Benedict’s test to show a no colour change
-add HCL to a fresh sample
-boil to hydrolyse glycosidic bonds
-neutralise the solution by adding solid sodium hydrogen carbonate
-test using Benedict’s reagent to show a red precipitate
Test for unknown conc. of reducing sugars
-make up several know conc of reducing sugar
-carry out the Benedict’s test
-use a colorimeter to measure the colour of each solution and plot using a calibration curve
-CONC ON X AND ABSORBANCE ON Y
-find the concentration of the sample using the calibration curve
Test for starch
-add two drops of KI to sample
-black shows presence of starch
lipids
-triglycerides found in food
-phospholipids help to form cell membrane of a cell
lipid functions (extra)
-conduct heat slowly SO good thermal and electrical insulators
-stored around delicate organs such as kidneys to protect them
outline and draw a triglyceride
-1 glyceride head
-3 fatty acid tails
-via ester bond
-via condensation reaction
saturated fatty acid definition
NO double bonds between carbon atoms within the hydrocarbon chain
unsaturated fatty acid definition
at least 1 double bond between carbon atoms within the hydrocarbon chain
triglyceride properties
-insoluble in water SO do not affect water potential
-low mass:energy ratio SO good stores of energy
-high hydrogen:water ratio SO good sources of water
test for lipids
-sample with ethanol
-shake
-add water drop by drop
-shake
-cloudy white emulsion if fat is present
Phospholipids
-similar structure to triglycerides
-one fatty acid replaced by a phosphate group
-phosphate group is polar
