carbohydrates

Question 1

what is the most common type of organic compound

Answer 1

carbohydrates

Question 2

what is the function of carbohydrates

Answer 2

storage of energy

Question 3

what is the smallest unit of a carbohydrate

Answer 3

monosaccharides

Question 4

give the three categories of carbohydrates

Answer 4

mono, di and poly saccharides

Question 5

what elements do carbohydrates contain

Answer 5

carbon, hydrogen and oxygen

Question 6

what’s the formula for carbohydrates

Answer 6

(CH2O)N

Question 7

how many atoms do carbohydrates usually contain

Answer 7

3-7

Question 8

give 5 functions of carbohydrates

Answer 8

major source of metabolic energy, structural material, components of nucleic acids (deoxy)ribose, component of ATP, recognition sites on the surface of cells

Question 9

how may you classify carbohydrates

Answer 9

complexity, size, functional group,

Question 10

what are simple carbohydrates?

Answer 10

monosaccharides

Question 11

what are some complex carbohydrates

Answer 11

disaccharides, oligosaccharides, polysaccharides

Question 12

give examples of different sizes of carbohydrates

Answer 12

triose (3C), Tetrose (4C), Pentose (5C), Hexoses, (6C), heptoses (7C)

Question 13

what is the name of the aldehyde functional group

Answer 13

aldose

Question 14

what is the name of the ketone functional group

Answer 14

ketose

Question 15

what position is aldose in the chain

Answer 15

at the end of the chain

Question 16

what position does ketose have in the chain

Answer 16

in the middle/centre of the chain

Question 17

what are some features of monosaccharides

Answer 17

colourless, crystalline solids, very soluble in water

Question 18

what are the most abundant sugars

Answer 18

hexoses

Question 19

what is the formula for hexoses

Answer 19

C6H12O6

Question 20

what happens to a straight chain form hexose when in an aqueous environment

Answer 20

they fold into rings due to a reaction of the functional group with a hydroxyl group

Question 21

what are the two pathways that can happen to the hydroxyl group during ring formation

Answer 21

it can be trapped in either alpha or beta form.

Question 22

what position is alpha form

Answer 22

when the hydroxyl group is down (opposite sides to the CH2OH group)

Question 23

what position is the beta form in

Answer 23

when the hydroxyl group is up (same side as the CH2OH group)

Question 24

what happens to the O from the carbonyl group when the reaction to form the ring takes place?

Answer 24

the O becomes a hydroxyl group and goes into either alpha or beta formation

Question 25

give an example of a hexose

Answer 25

fructose, glucose, galactose

Question 26

what is an isomer?

Answer 26

molecule with the same chemical formula but with a different arrangement of atoms

Question 27

what is a stereoisomer

Answer 27

atoms of a molecule bonded together in the same order but the have a different 3D organisation of atoms around one of their asymmetric carbons i.e glucose and galactose

Question 28

give two examples of pentoses

Answer 28

ribose and deoxyribose

Question 29

what is the bond formed between two monosaccharides after a condensation dehydration reaction

Answer 29

glycosidic linkage

Question 30

explain how a glycosidic linkage occurs

Answer 30

the hydroxyl group of one monosaccharide combines with the hydrogen of another, releasing a water molecule and forming a covalent bond

Question 31

what does a 1-4 linkage mean?

Answer 31

carbon 1 linking with carbon 4

Question 32

name 3 common disaccharides

Answer 32

lactose, maltose, sucrose

Question 33

can polysaccharides pass out of cells

Answer 33

no

Question 34

are polysaccharides easily soluble in water

Answer 34

no

Question 35

give 3 examples of polysaccharides

Answer 35

starch, glycogen, cellulose

Question 36

give an example of a modified polysaccharide

Answer 36

chitin

Question 37

give the two types of starch

Answer 37

amylose and amylopectin

Question 38

write down the function of starch, glycogen, cellulose and chitin

Answer 38

energy storage, energy storage, structural role and structural role

Question 39

true or false starch is a mixture of two polysaccharides

Answer 39

true amylose and amylopectin

Question 40

how is excess glucose stored in plants

Answer 40

stored as starch in roots and seeds

Question 41

are the glucose monomoers in the alpha or beta form in starch

Answer 41

alpha

Question 42

what do the chains of amylose look like? branched/unbranched, helical/pleated

Answer 42

unbranched helical structure

Question 43

what linkage takes place in amylose?

Answer 43

1-4 linkage

Question 44

what do the chains of amylopectin look like? branched/unbranched, alpha or beta

Answer 44

branched helical alpha

Question 45

what linkages take place in amylopectin?

Answer 45

1-4 in the main chains and 1-6 in the branches

Question 46

how spaced apart are the branches in amylopectin

Answer 46

every 30th monomer there is a short side chain

Question 47

what is glycogen

Answer 47

the stored form of glucose in humans + other vertebraes

Question 48

are there more branches in glycogen or amylopectin

Answer 48

glycogenwh

Question 49

where is glycogen typically stored

Answer 49

liver + muscle cells

Question 50

whenever blood glucose levels decreas, glycogen is broken down via hydrolysis- what is hydrolysis

Answer 50

the opposite of a condensation reaction. it is a catabolic reaction, where a water molecule is added to break down larger molecules into smaller ones

Question 51

define glycogenolysis

Answer 51

when glycogen is broken down into glucose when energy is needed

Question 52

is cellulose branched/unbranched and alpha or beta

Answer 52

unbranched Beta

Question 53

what linkage takes place in cellulose?

Answer 53

1-4 linkage

Question 54

are there side chains in cellulose

Answer 54

no- so the molecules lie close together

Question 55

why is cellulose so rigid/stiff

Answer 55

hydrogen bonds form between the chains

Question 56

what form are the glucose monomers in cellulose

Answer 56

B form

Question 57

can the B glycosidic linkages be broken down by human digestive enzymes

Answer 57

no, we do not have the enzymes to do so

Question 58

where can chitin be found in nature

Answer 58

arthropods i.e insects and crustaceans

Question 59

how does chitin differ from regular carbohydrates

Answer 59

it has modified glucose molecules that have a nitrogen-containing functional group

Question 60

what is glucosamine

Answer 60

glucose modified by addition of amino groups