Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

jc1 biology > carbohydrates > Flashcards

carbohydrates Flashcards

(69 cards)

Start Studying
1
Q

what are carbohydrates?

A

carbohydrates are organic compounds made up of carbon, hydrogen and oxygen atoms
there are usually twice as many hydrogen atoms as oxygen atoms, in the ratio of 2:1

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

general formula of carbohydrates

A

Cₓ(H₂O)ᵧ

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

all carbohydrates contain several

A

-OH groups, one attached to every carbon in the skeleton except for the carbonyl group (C=O)

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

different classes of carbohydrates + their corresponding no. of sugar units

A

monosaccharides (reducing) - 1
disaccharide - 2
oligosaccharides - 3-10
polysaccharides - >10-1000s

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

which classes of carbohydrates are considered sugars?

A

monosaccharides and disaccharides

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

general formula of monosaccharides

A

(CH₂O)ₙ , where 3 ≤ n ≤9

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

different classifications of monosaccharides + their corresponding no. of carbon atoms

A

(the stuff on the right side dont need memorise)

triose (3C) - e.g. glyceraldehyde
tetrose (4C) - rare
pentose (5C) - e.g. ribose, deoxyribose
hexose (6C) - e.g. glucose, fructose, galactose
heptose (7C)

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

molecular formula of hexoses (6C sugars)

A

C₆H₁₂O₆

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

What functional group does the 1st carbon (¹C) of glucose contain?

A

an aldehyde group (-CHO)

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

What functional group is found on carbons ²C to ⁵C of glucose?

A

Hydroxyl groups (–OH)

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

In what forms can glucose molecules exist?

A

Open chain form and stable ring structure

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

What structure do glucose molecules easily form?

A

A stable ring structure (like most hexoses and pentoses)

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

how is the stable ring structure formed?

A

¹C (with the aldehyde group) reacts favourably with the oxygen atom on ⁵C to form a 6-sided ring structure called a pyranose ring.

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

what are the two possible ring forms (isomers) of glucose

A

α-glucose and β-glucose

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

how to differentiate between α-glucose and β-glucose?

A

look at the OH group of C1. OH group of alpha is below, OH group of beta is above

ABBA: Alpha below Beta above

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

common hexose sugars

A

glucose, galactose, fructose

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

general formula of disaccharides

A

C₁₂H₂₂O₁₁

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

common disaccharides

A

maltose, lactose, sucrose

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

a disaccharide consists of

A

two monosaccharides joined by a glycosidic bond.

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

formation of a glycosidic bond

A

A glycosidic bond is formed by a polymerisation reaction called condensation reaction between two monosaccharide units (usually hexoses) combining with the elimination of a molecule of water.

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

what is a α(1->4) glycosidic bond

A

a glycosidic bond formed between carbon 1 of one monosaccharide and carbon 4 of the other

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

describe the breakage of a glycosidic bond

A

The addition of water, under suitable conditions, is necessary if the disaccharide is to be split into its constituent monosaccharides; this process is known as hydrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

the location (animal/plant) of maltose, lactose and sucrose:

A

maltose: animals and plants
lactose: animals
sucrose: plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

monosaccharide constituents of maltose, lactose and sucrose

A

maltose: 2 glucose molecules
lactose: glucose and galactose
sucrose: glucose and fructose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
is maltose/lactose/sucrose a reducing sugar?
maltose: yes lactose: yes sucrose: no
26
general formula of polysaccharides
(C₆H₁₀O₅)ₙ where n = no. of hexose units linked together in the polysaccharides.
27
common polysaccharides
starch, glycogen, cellulose
28
what are polysaccharides?
polymers of a few hundred or thousand monosaccharides.
29
what is a polymer?
(just understanding is enough, no need exact wording) a substance of large, relative molecular mass and is formed as a result of joining together a large number of basically similar smaller molecules (monomers) in an enzyme-mediated condensation reaction
30
structure of starch
A polymer of α glucose units. It has two main components, namely amylose and amylopectin.
31
what are the monomers of amylose?
α glucoses
32
bonds in amylose
α(1->4) glycosidic bonds
33
structure of amylose
- Is unbranched helical chain with six glucose residues for every complete turn of the helix. - Helical chain is formed as a result of intra-chain hydrogen bonding between hydroxyl groups of glucose.
34
how is amylose hydrolysed?
α(1->4) glycosidic bonds break by amylase.
35
solubility of amylose in water
insoluble
36
why is amylose insoluble in water?
due to: - its bulky size (macromolecule) - many -OH groups are protected within the helical regions of the molecule and are unavailable for water molecules to hydrogen bond with.
37
monomers of amylopectin
α glucoses
38
bonds in amylopectin
α(1->4) glycosidic bonds and α(1->6) glycosidic bonds
39
structure of amylopectin
- Is helical chains which are highly branched and thus more compact. - branch points are formed by α(1->6) glycosidic bonds.
40
hydrolysis of amylopectin
α(1->6) glycosidic bonds break by de-branching enzyme (-> more linear chains for higher rate of hydrolysis by amylase)
41
solubility of amylopectin in water
insoluble
42
why is amylopectin insoluble in water?
(basically same as amylose) due to: - its bulky size (macromolecule) - many -OH groups are protected within the helical regions of the molecule and are unavailable for water molecules to hydrogen bond with.
43
how does starch being composed of thousands of α glucose linked by α(1->4) glycosidic bonds relate to its function?
- Stores large amount of energy - α(1->4) glycosidic bonds can be broken by amylase, hydrolysing starch into glucose -> glucose for respiration since it is the main respiratory substrate
44
how does amylose chains being helical in shape, maintained by intra-chain hydrogen bonding between hydroxyl groups of glucoses, relate to its function?
compact, ideal for storage
45
how does amylopectin being highly branched due to branch points maintained by α(1->6) glycosidic bonds relate to its function?
- compact, ideal for storage - Debranching enzymes break α(1->6) glycosidic bonds, this converts the branched structure of amylopectin into a more linear structure, increases the accessibility of the remaining linear chains to amylase, thus increases the rate of hydrolysis.
46
how does -OH groups of glucose being occupied in intra-chain hydrogen bonding relate to its function?
unavailable for interaction with water molecules -> *insoluble*, therefore osmotically inactive -> Will not affect osmotic concentration in cells -> water cannot be absorbed into the cells, and the cells will not swell.
47
monomer of glycogen
α glucose
48
how is the molecular structure of glycogen similar/different to amylopectin?
its molecular structure is similar to amylopectin, but it is larger and much more highly branched
49
how does glycogen being more highly branched than amylopectin affect how easily hydrolysed it is?
glycogen is more easily hydrolysed to α glucose
50
how is glycogen hydrolysed?
by: -> Debranching enzymes which break α(1->6) glycosidic bonds. -> Glycogen phosphorylase which breaks α(1->4) glycosidic bonds.
51
why is glycogen is more highly branched and larger than amylopectin?
because animals' energy requirements are higher than plants
52
what is the function of glycogen?
energy storage in animals
53
primary function of cellulose
provide strength, rigidity, and structural support to plant cells
54
functions of cellulose, apart from primary function
protect plant cells and cytoplasm from damage and mechanical injuries
55
how permeable is the cellulose cell wall to water and solutes?
fully permeable
56
monomers of cellulose
β glucose
57
bonds in cellulose
β(1->4) glycosidic bonds
58
formation of β(1->4) glycosidic bonds in cellulose requires the ___ of ___ glucose residues
180° rotation of alternating glucose residues
59
is cellulose straight chains or branched?
straight chains
60
describe the cross-linking between chains in cellulose
Hydroxyl groups (-OH) (at carbon atom 2) project outwards, alternately from both sides of each chain, allowing for the formation of hydrogen bonds between adjacent chains, thus establishing a rigid cross-linking between the chains. Thus many unbranched linear chains run parallel to each other.
61
what are numerous cellulose chains bonded together called
microfibrils
62
what are numerous microfibrils together called
macrofibril
63
what are macrofibrils coiled into large bundles called
fibers
64
how does cellulose being composed of thousands of β glucose linked by β(1->4) glycosidic bonds relate to its function
- Stores large amount of energy - ꞵ(1->4) glycosidic bonds can be broken by cellulase, hydrolysing cellulose into glucose -> glucose for respiration since it is the main respiratory substrate
65
how does the 180° rotation of alternate β glucose residues in cellulose relate to its structure and function
Result in long straight chains of cellulose which allow for the formation of stable microfibrils
66
how does microfibrils further bundling together to form macrofibrils and then fibers in cellulose relate to its function
- The bundling of chains and inter-chain hydrogen bonding between adjacent cellulose chains contribute to the strength and rigidity of these microfibrils. - Resulting in *high tensile strength and mechanical strength in the cell wall - Thus protect the plant cell from mechanical damage.
67
how does -OH groups are projected outward of cellulose chains due to the rotation of every alternate glucose relate to the structure and function of cellulose
- Allow inter-chain hydrogen bond to be formed between adjacent chains - Such cross-linkages increase tensile strength. - The lack of free –OH groups in this large molecule mean that it does not interact with water molecules, hence it is *insoluble in water. - Being *insoluble make cellulose a good material for forming structural support.
68
how does spaces between the macrofibrils in cellulose relate to its structure and function
Makes it a *fully permeable structure, hence cell wall does not restrict movement of substance in and out of cell.
69
where is starch, glycogen and cellulose found respectively
starch - plant glycogen - animal cellulose - plant cell wall

jc1 biology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions