Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

2.1.2 biological molecules > Carbohydrates - polysaccharides > Flashcards

Carbohydrates - polysaccharides Flashcards

You may prefer our related Brainscape-certified flashcards:
Organic Chemistry 101 flashcards
1
Q

what is a polysaccharide

A

polymers containing many monosaccharides linked by glycosidic bonds
they are polymers of monosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are polysaccharides mainly used as

A

energy stores and structural components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

name the energy stores

A

starch (plants) and glycogen (animals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

name the structural component

A

cellulose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is alpha glucose

A

important molecule as it is the substrate for respiration which occurs in the mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how does alpha glucose provide energy

A

enzymes break apart alpha glucose molecules which generate energy in the form of ATP which is utilised by the rest of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the equation for respiration

A

glucose + oxygen —-> carbon dioxide + water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how can you create a store of energy

A

if you join lots of glucose molecules together into polysaccharides you can create a source of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how do plants store energy

A

as starch in chloroplasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how do animals store energy

A

as glycogen in cells of muscles and livers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how are glycogen and starch compact

A

they do not occupy a large amount of space as they both occur in dense granules within the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how can glucose be used for respiration

A

polysaccharides hold glucose molecules in chains so they can be easily snipped from the ends of the chains by hydrolysis when required for respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which chains of glucose are branched and which are unbranched

A

amylose is unbranched whereas amylopectin is branched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

are branched or unbranched chains more compact.

A

branched chains are more compact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what do branched chains allow

A

they offer the chance for lots of glucose molecules to be snipped off by hydrolysis at the same time, when lots of energy is required quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why is it important to have alpha glucose as a respiratory substrate

A

excess amount of glucose in body fluids are very dangerous for cell structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is glucose a product of

A

photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is glucose a substrate of

A

respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

are polysaccharides more or less soluble in water than monosaccharides

A

less soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

why are polysaccharides less soluble

A

because of their sieze and also because regions which could hydrogen bond with water are hidden away inside the molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what would happen if glucose molecules dissolved in the cytoplasm

A

the water potential would reduce and excess water would diffuse in disrupting normal workings of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

is starch soluble in water

A

no, it is insoluble in water

23
Q

why is it important that starch doesnt doesnt dissolve in water

A

so it doesn’t affect osmosis

24
Q

how much of starch does amylose and amylopectin make up

A

20% amylose and 80% amylopectin

25
Q

what is amylose

A

long unbranched chain of alpha glucose that has a compact coiled structure. it is good for storage

26
Q

what is amylopectin

A

long branched chain of alpha glucose. glucose can be released quickly as it is easier for enzymes to get to the branches

27
Q

how does alpha glucose form amylose

A

condensation

28
Q

how does amylose break down into alpha glucose

A

hydrolysis

29
Q

what is the monomer for amylose and amylopectin

A

alpha glucose

30
Q

what type of bonding does amylose have

A

1-4 glycosidic bonding

31
Q

describe the formation of amylose

A

as it forms it coils making it compact (due to the bond angles, this is stablisied with hydrogen bonds. it isnt branched so it has few break off points.

32
Q

what makes amylose less soluble

A

hydroxyl groups on carbon 2 are situated on the inside of the coil making the molecule less soluble and allowing hydrogen bonds to form to maintain the coils structure

33
Q

what is the monomer for amylopectin

A

alpha glucose

34
Q

what type of bonding does amylopectin have

A

1-4 and 1-6 glycosidic bonding

35
Q

describe the formation of amylopectin

A

as it forms, its branched structures give more break off points (due to the bonding). it coild together into a spiral shape held together with hydrogen bonds but with branches emerging from the spirals

36
Q

how do animals store carbohydrates

A

glycogen

37
Q

what structure is glycogen similar to

A

amylopectin as it has many alpha 1-6 glycosidic bonds that produce an even more branched structure.

38
Q

how is glycogen stored

A

as small granules in the muscles and liver

39
Q

what is the difference between starch and glycogen

A

less dense and more soluble than starch and broken down more rapidly. it indicates higher metabolic requirements of animals compared with plants

40
Q

how are the bonds like in glycogen

A

1,4 glycosidic bonds between carbon 1 and 4 and branches formed by glycosidic bonds between carbon 1 and 6

41
Q

why does glycogen have less tendency to coil

A

1-4 bonded chains tend to be smaller than in amylopectin making it less likely to coil

42
Q

why does glycogen have more branches

A

it makes it more compact so makes it easier to remove monomer units as there are more ends

43
Q

describe cellulose

A

found in plants to form the cell walls. it is a tough, insoluble and fibrous substance.

44
Q

what is cellulose made of

A

from long chains of 15000 beta glucose molecules bonded together through condensation reactions to form glycosidic bonds.

45
Q

what is different about the structure and bonding of cellulose

A

its made from beta glucose. the 2nd beta glucose is rotated by 180 degrees. this is so the hydroxyl groups are more closer and bond together. the removal of water forms a glycosidic bond.

46
Q

why are cellulose chains straight

A

they lie side by side as a result of the bonding. the hydrogen and hydroxyl groups on carbon 1 are inverted in beta glucose. this means that every other beta glucose molecule chain is rotated by 180 degrees. this and the beta 1-4 glycosidic bonding help prevent the chain from spiralling.

47
Q

how are hydrogen bonds formed in cellulose chains

A

they form between rotated beta glucose molecules in each chain giving it additional strenght. the hydroxyl group on carbon 2 sticks out, enabling hydrogen bonds to be formed between chains.

48
Q

how are macrofibrils formed from microfibrils

A

when 60 to 70 cellulose chains are bound together they form microfibrils which are 10-30nm in diameter. these bundle into macrofibrils containing 400 microfibrils which are embedded into pectin to form cell walls. macrofibrils run in all directions criss crossing the wall for extra strength

49
Q

why is cellulose an excellent material for plant cell walls

A

microfibrils and macrofibrils have very high tensile strength because of the strength of the glycosidic bonds but also because of hydrogen bonds between chains.

50
Q

why is it difficult to digest cellulose

A

the glycosidic bonds between glucose molecules are less easy to break. most animals dont have an enzyme to catalyse the reaction

51
Q

what make the cell wall fully permeable

A

because plants do not have a rigid skeleton, each cell needs to have strenght to support the whole plant. there is space between macrofibrils for water and mineral ions to pass on their way into and out of cells

52
Q

what prevents the cell wall from bursting when turgid

A

the walls high tensile strength prevents plant cells from bursting when turgid. turgid cells press against each other supporting the plant and protecting the cell membrane

53
Q

what are bacteria cell walls made of

A

peptigoglycan. this is made from long polysaccharide hains that lie in parallel, cross linked by short peptide chains.

2.1.2 biological molecules (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions