Carbohydrates

Question 1

what chemical elements are carbohydrates made up of?

Answer 1

C H O

Question 2

what are the three types of carbohydrates?

Answer 2

monosaccharides, disaccharides, polysaccharides

Question 3

how can sugars be classified?

Answer 3

reducing and non-reducing

Question 4

how are reducing and non-reducing sugars classified?

Answer 4

it is dependant on their ability to share electrons (reducing sugars can donate electrons -the carbonyl group becomes oxidised- the sugars become the reducing agent)

Question 5

nemonic for lose/ gain of electrons

Answer 5

OIL RIG

Question 6

can non reducing sugars donate electrons?

Answer 6

no tf they cannot be oxidised

Question 7

how are monosaccharides named?

Answer 7

number of carbons
eg 5 carbons—-> pentose

Question 8

how are sugars identifiable?

Answer 8

-ose ending

Question 9

what is the molecular formula of glucose?

Answer 9

C6H12O6

Question 10

what is the main function of glucose?

Answer 10

energy source (main substrate used in respiration, releasing energy for the production of ATP)

Question 11

what is an isomer?

Answer 11

same molecular formula but different atom arrangement in space (tf diff properties)

Question 12

what are the two isomers of glucose?

Answer 12

alpha (α) glucose and beta (β) glucose

Question 13

what does structural variety in carbohydrates result in?

Answer 13

different functions between carbohydrates

Question 14

what does glucose form when in aqueous solutions?

Answer 14

a ring structure

Question 15

where is the hydroxyl on C1 in beta (β) glucose?

Answer 15

think drawing (β)
above

Question 16

where is the hydroxyl on C1 in alpha (α) glucose?

Answer 16

below

Question 17

is starch made of alpha (α) glucose or beta (β) glucose?

Answer 17

alpha (α) glucose

Question 18

is glycogen made of alpha (α) glucose or beta (β) glucose?

Answer 18

alpha (α) glucose

Question 19

is cellulose made of alpha (α) glucose or beta (β) glucose?

Answer 19

beta (β) glucose

Question 20

what polysaccharides are formed from the different isomers of glucose?

Answer 20

strach, glycogen, cellulose

Question 21

what are sugars containing 5 carbons called?

Answer 21

pentose sugars

Question 22

what are two important examples of pentose sugars?

Answer 22

ribose and deoxyribose

Question 23

where is ribose found?

Answer 23

the nucleotides that make up RNA

Question 24

where is deoxyribose found?

Answer 24

the nucleotides that make up DNA

Question 25

what is the difference between ribose and deoxyribose?

Answer 25

deoxyribose has lost 1 oxygen on C2

Question 26

when are polysaccharides and disaccharides formed?

Answer 26

when two hydroxyl groups (-OH) on diff monosaccharides interact to form a strong covalent bond (glycosidic bond)

Question 27

how are glycosidic bonds formed?

Answer 27

through condensation reactions

Question 28

what is the result of a glycosidic bond being formed?

Answer 28

-either a polysaccharide or disaccharide -1 water molecule being removed

Question 29

α glucose + α glucose-->

Answer 29

maltose

Question 30

α glucose + β galactose-->

Answer 30

lactose

Question 31

α glucose + fructose-->

Answer 31

sucrose

Question 32

β glucose + β glucose-->

Answer 32

cellobiose

Question 33

what are the features of monosaccharides?

Answer 33

-the simplest carbohydrates -sweet-tasting -soluble -full of C-H bonds for energy storage

Question 34

what do tri/tetr-oses exist as?

Answer 34

chains

Question 35

what do pent/hex-oses exist as?

Answer 35

rings

Question 36

what is the colour change when using Benedict's?

Answer 36

blue green yellow organge-red

Question 37

reducing sugars reduce Cu2+--->

Answer 37

Cu+ (forming copper (I) oxide precipitate

Question 38

can non-reducing sugars be tested with Benedict's?

Answer 38

no, the glycosidic bond must be hydrolysed to free the reducing groups

Question 39

what is the test for non-reducing sugars?

Answer 39

-boil with HCl (to break into monosaccharides) -cool and add NaHCO3 (to neutralise) -test with Benedict's, like reducing

Question 40

as there are many different monosaccharides...

Answer 40

there are many different types of glycosidic bonds

Question 41

what type of glycosidic bond does maltose have?

Answer 41

α 1,4 (disaccharide)

Question 42

what type of glycosidic bond does sucrose have?

Answer 42

α 1,2 (disaccharide)

Question 43

what type of glycosidic bond does cellulose have?

Answer 43

β 1,4 (polysaccharide)

Question 44

what type of glycosidic bond does amylose have?

Answer 44

α 1,4 (polysaccharide)

Question 45

what type of glycosidic bond does amylopectin have?

Answer 45

α 1,4 and 1,6 (polysaccharide)

Question 46

what is each glycosidic bond catalysed by?

Answer 46

by enzymes specific to which OH groups are interacting

Question 47

what examples of polysaccharides am I expected to know

Answer 47

starch, glycogen and cellulose

Question 48

what are polysaccharides?

Answer 48

macromolecules, made up of lots of monomers joined by glycosidic bonds, formed by condensation reactions