Carbs and lipids

Question 1

Monomer definition

Answer 1

-small identical molecules
-which can be condensed to make larger polymers called polymers
-via a condensation reaction

Question 2

Polymers definition

Answer 2

-large molecules
made from joining many identical monomers together
-via a condensation reaction

Question 3

condensation reaction definition

Answer 3

removal of a water molecule

Question 4

hydrolysis reaction

Answer 4

addition of water molecule

Question 5

draw alpha-glucose

Answer 5

-6 carbons
-12 hydrogens
-6 oxygens
-OH are parallel

Question 6

draw beta-glucose

Answer 6

-6 carbons
-12 hydrogens
-6 oxygens
-OH are diagonal

Question 7

name the bond between glucose molecules

Answer 7

glycosidic bond

Question 8

Monosaccharide examples

Answer 8

glucose, fructose, galactose

Question 9

Disaccharide examples

Answer 9

maltose, sucrose, lactose

Question 10

Polysaccharides examples

Answer 10

glycogen, starch, cellulose

Question 11

Glycogen

Answer 11

-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

Question 12

amylose properties and benefits

Answer 12

-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

Question 13

amylopectin

Answer 13

-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

Question 14

cellulose

Answer 14

-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

Question 15

microfibrils

Answer 15

-wound together to form cellulose fibres
-provides strength and support to plant cells and cell walls are made out of cellulose

Question 16

Benedict’s test for REDUCING SUGAR

glucose, galactose, lactose, maltose, fructose

Answer 16

-equal amounts of Benedict’s solution to sample
-heat to 95 degrees
-change from blue to red precipitate shows reducing sugar is present

Question 17

Benedict’s test for NON REDUCING SUGAR

sucrose

Answer 17

-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

Question 18

Test for unknown conc. of reducing sugars

Answer 18

-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

Question 19

Test for starch

Answer 19

-add two drops of KI to sample
-black shows presence of starch

Question 20

lipids

Answer 20

-triglycerides found in food
-phospholipids help to form cell membrane of a cell

Question 21

lipid functions (extra)

Answer 21

-conduct heat slowly SO good thermal and electrical insulators

-stored around delicate organs such as kidneys to protect them

Question 22

outline and draw a triglyceride

Answer 22

-1 glyceride head
-3 fatty acid tails
-via ester bond
-via condensation reaction

Question 23

saturated fatty acid definition

Answer 23

NO double bonds between carbon atoms within the hydrocarbon chain

Question 24

unsaturated fatty acid definition

Answer 24

at least 1 double bond between carbon atoms within the hydrocarbon chain

Question 25

triglyceride properties

Answer 25

-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

Question 26

test for lipids

Answer 26

-sample with ethanol
-shake
-add water drop by drop
-shake
-cloudy white emulsion if fat is present

Question 27

Phospholipids

Answer 27

-similar structure to triglycerides
-one fatty acid replaced by a phosphate group
-phosphate group is polar