carbs and lipids

Question 1

eg of monomers

Answer 1

monosaccharides, amino acids, nucleotides

Question 2

egs of polymers

Answer 2

polysaccharides, polypeptide, polynucleotide

Question 3

bond for each 3 monomers m,aa,n

Answer 3

glycosodic, peptide, phosphodiester

Question 4

eg of polysaccharides

Answer 4

starch, glycogen, cellulose

Question 5

egs of amino acids

Answer 5

enzymes, haemoglobin

Question 6

egs of polynucleotides

Answer 6

dna, rna

Question 6

alpha glucose structure

Answer 6

Question 6

beta glucose structure

Answer 6

Question 7

glucose + glucose

Answer 7

maltose

Question 8

galactose + glucose

Answer 8

lactose

Question 9

glucose + fructose

Answer 9

sucrose

Question 10

bonds of amylopeptin (starch)

Answer 10

carbon 1-4 glycosidic bonds which make it compact - helical structure

Question 11

amylose - bonds (starch)

Answer 11

branched chains - carbon 1-6 and 1-4 glycosidic bonds which gives a large surface area for rapid hydrolisis by enzymes to release glucose for respiration

Question 12

advantages of starch structure

Answer 12

insoluble so doesnt affect water potential
large so doesn’t diffuse out of cells
coils into compact shape

Question 13

advantages of structure for glycogen

Answer 13

more higly branched
and short chains
and larger surface area
lead to glycogen being more rapidly hydrolysed into glucose used in respiration

Question 14

what is made up of alpha glucose?

Answer 14

starch (plants) and glycogen (animals)

Question 15

what is made up of beta glucose?

Answer 15

cellulose - what plant cell walls are made from

Question 16

structure of cellulose

Answer 16

long straight unbranched chains joined together in layers by weak hydrogen bonds to form microfilbrils

Question 17

advantages of cellulose structure

Answer 17

weak h bonds provide strength as they are large in numbers

Question 18

what are egs of reducing sugars

Answer 18

glucose galactose maltose fructose lactose

Question 19

what are egs of non reducing sugars

Answer 19

sucrose

Question 20

benedicts test for reducing sugars

Answer 20

add 2cm3 benedicts solution to a sample, heat to 95C
a coloured change from blue to red precipitate visible

Question 21

benedicts test for non reducing sugars

Answer 21

if no change in benedicts test for reducing sugar
head a sample with acid and heat to 95C
then neutralise with alkali
add 2cm3 benedicts solution
heat to 95C
red precipitate

Question 22

how you would produce a calibration curve for a reducing sugar of unknown concentration and abtain results

Answer 22

make up several random known conc of a reducing sugar (glucose, eg)
carry our benedicts test on each sample
use a colorimeter to measure absorbance reading (au)
plot a calibration curve
find the conc of unknown sample using calibration curve

Question 23

test for starch

Answer 23

add 2 drops of KI solution to sample black colour indicates starch presence

Question 24

fucntions of lipids

Answer 24

conduct heat slowly, good thermal insulator stored around delicate organs to protect

Question 25

triglyceride strcutre

Answer 25

made from one molecule of glycerol to three fatty acids joined by ester bonds

Question 26

why are triglycerides not a polymer

Answer 26

not made up of the same/similar monomers

Question 27

unsaturated fatty acid vs saturated fatty acid structure difference

Answer 27

saturated - no double bonds between carbon atoms (solid at room temp as its straight and closely packed) unsaturated - double bond between at least one carbon atom so has a kink, leading to being liquid at room temp

Question 28

advantages in triglyceride structure

Answer 28

low mass to energy ratio so makes them a good source of energy they dont affect water potential of a cell as they are insoluble in water high hydrogen to oxygen ratio so they are a good source of water when broken down

Question 29

emulsion test for lipids

Answer 29

crush sample sample added to 2cm3 of ethanol shake add a few drops of water shake white emulsion layer forms

Question 30

phospholipid structure

Answer 30

one glycerol 2 fatty acids one phosphate group

Question 31

charge of phosphate group vs fatty acid tails

Answer 31

phosphate group - negative cahrge (polar) fatty acid tails - no cahrge (non-polar)

Question 32

phospho-glycerol head vs fatty acid tails attraction to water

Answer 32

phospho-glycerol head hydrophillic fatty acid tails hydrophobic allows the phospholipids to form a bilayer in water, forming the basis of the cell membrane

Question 33

What are monomers?

Answer 33

The smaller units from which larger molecules are made

Question 34

What are polymer?

Answer 34

Molecules made from a large number of monomers joined together

Question 35

What is a condensation reaction?

Answer 35

When two molecules are joined together with the formation of a chemical bond and involves the removal of a molecule of warer

Question 36

Describe how you would produce a calibration curve for a reducing sugar of unknown concentration and use it to obtain results

Answer 36

1. Make up several known concentrations of maltose / glucose / lactose / galactose / fructose; 2. Carry out the Benedict’s test on each sample; 3. Use a colorimeter to measure the colour intensity of each solution and plot a calibration curve; 4. Known Conc. on X axis and absorbance / transmission on Y. 5. Find the concentration of the unknown sample using the calibration curve

Question 37

To determine the concentration of an unkown solution to you would:

Answer 37

1. Make up different known concentrated solutions of named sugar. 2. Carry out the [correct biochemical test] on each sample. 3. Take readings of absorbance using a colorimeter. 4. Plot readings to produce a graph called a calibration curve, with: X axis (→) concentration of named sugar / mol dm-³ Y axis (↑) absorbance/AU/% 5. Draw Line Of Best Fit 6. Read unknown sample absorbance value from the calibration curve and read off the corresponding concentration of solution.