Amir Flashcards
1
Q
What are monosaccharides
A
The monomers from which larger carbohydrates are made
2
Q
3 monosaccharides
A
Glucose
Galactose
Fructose
3
Q
Where is glucose commonly found
A
Food/nature
4
Q
Where is galactose commonly found
A
Milk
5
Q
Where is fructose commonly found
A
Fruit
6
Q
What are disaccharides
A
They are formed by the condensation of two monosaccharides
7
Q
What is the bond formed when two monosaccharides condense together
A
Glycosidic
8
Q
3 disaccharides
A
Maltose
Lactose
Sucrose
9
Q
What is maltose made up from
A
A glucose and A glucose
10
Q
What is sucrose made up from
A
A glucose and fructose
11
Q
What is lactose made up from
A
B glucose and galactose
12
Q
What are carbohydrates
A
The polymers formed from monomers called monosaccharides
13
Q
Carbohydrates are composed of which 3 elements
A
Carbon
Hydrogen
Oxygen
14
Q
The enzyme that digests maltose
A
Maltase
15
Q
The enzyme that digests sucrose
A
Sucrase
16
Q
The enzyme that digests lactose
A
Lactase
17
Q
Where are the enzymes that digest disaccharides made
A
Small intestine
18
Q
General formula for carbohydrates
A
Cn (H20) n
19
Q
What does the general formula for carbohydrates show
A
Twice as many hydrogen atoms as there are oxygen and carbon
20
Q
How do you name monosaccharides
A
According to the number of carbons they have e.g Triose, Tetrose, Pentose
21
Q
Monosaccharides have the same chemical formulas but
A
Different structural formulas
22
Q
Glucose exists as
A
Two structural isomers, Alpha and Beta
23
Q
What is the difference between A and B glucose
A
In A, The OH group on C1 points down
In B, the OH group on C1 points up
24
Q
What happens when two monosaccharides condense together
A
One monosaccharide loses a H atom from C1
The other loses an OH group from C4
25
What is a condensation reaction
Removing water
26
What is a hydrolysis reaction
Adding water
27
Are all monosaccharides reducing sugars
Yeah
28
Are all disaccharides reducing sugars
No, only maltose and lactose
29
What disaccharide is a non reducing sugar
Sucrose
30
Benedicts test
```
1ml of sample placed into test tube
10 drops of benedicts solution added
Heat at 90 degrees for 2-3 mins
Should be fewer 2+ Ions of copper
Use a colourimetre to measure absorbance of 2+ ions
Or observe colour change
```
31
Estimating conc of glucose in an unknown substance
Have a set of known glucose concs
Keep control variables
Use a colourimetre to measure absorbances of known concs
Produce a calibration curve
Repeat benedicts test for unknown substance
Extrapolate
Compare on calibration curve and estimate conc
32
Control variables for benedicts test
Vol of glucose
Conc of benedicts
Vol of benedicts
Time for heating
33
Benedicts test for non reducing sugars
Boil in acid to hydrolise it so water breaks the glycosidic bond
2 monosaccharides are formed
Retest new solution doing normal benedicts test
34
What are polysaccharides
Formed by the condensation of glucose units
35
3 polysaccharides
Glycogen
Starch
Cellulose
36
Starch is made from polymers of
Alpha glucose
37
Is starch soluable
No
38
Starch is made up of
Amylose and amylopectin
39
Is starch ever found in animals
No
| Only plants
40
What is amylose
Straight chain polysaccharide
41
What bonds do amylose have
1-4 glycosidic
42
Why does amylose form spirals
The spirals are held together by H bonds
| The coils are compact and store lots of glucose
43
Why is starch a good energy store
```
Insoluble
- doesn’t affect water potential and will not diffuse out
Compact
- lots of glucose stored in small space
Hydrolises into A glucose
- more easily transported
```
44
What is cellulose
A tough structural carbohydrate which is difficult to break down/digest
45
What are the chains like in cellulose
Straight and unbranched so will not coil
46
Why are chains in cellulose parallel
So H bonds can form links
| Individual H bonds are weak but many can add strength
47
How do H bonds form in cellulose
B glucose flips 180 degrees to form a H bond on C4 (every other B glucose is flipped)
48
Why is cellulose good at adding strength
Molecules form to group microfibrils which group again to form fibres
49
What is glycogen
A major carbohydrate storage product of animals (known as animal starch)
50
Where is glycogen stored
Stored as small granules in
Liver to be released into blood for widespread use
Muscles for use in muscles only
51
Where is glycogen found
Animal and bacteria cells only
52
Structure of glycogen compared to amylopectin
Glycogen has
Shorter 1-4 glycosidic bonds
Greater branching bc there are more 1-6 glycosidic bonds to allow branching
53
What structure does amylopectin have
Branched because A glucose is also linked to 1-6 glycosidic bonds
54
Why is branching good in amylopectin
Larger SA
More easily broken down
Faster hydrolysed for use
55
What bonds does amylopectin have
1-4 and 1-6 glycosidic bonds
56
Why is glycogen a good energy store
```
Insoluble
- doesn’t draw water in via osmosis
Compact
- lots stored in a small space
Highly branched
- more ends acted on by enzymes
- more quickly broken into glucose monomers for respiration
```
57
Cellulose is made from polymers of
Beta glucose
58
Glycogen is made from polymers of
Alpha glucose
59
What are lipids
Groups of molecules than can either be
Fats (solid at room temp)
Oils (liquid at room temp)
60
Fats are made from which 3 elements
Carbon
Hydrogen
Oxygen
61
How do fats differ from carbohydrates
The proportions of elements are different
There is a lower amount of oxygen
And C-H bonds are energy rich
62
Function of fats
Stores energy (subcutaneous- under skin)
Provides warmth
Protection around organs (gives shock absorption)
Was for protection (to trap pathogens and dirt)
63
What are triglycerides
Lipids consisting of
One glycerol molecule
Three fatty acid molecules
64
What are the bonds formed between the molecules in a triglyceride
Covalent
| Called Ester bonds
65
What reaction do Ester bonds form in
Condensation
66
What is a fatty acid
```
Chain of carbon atoms
The terminal (1st) one has an OOH group attatched
```
67
What is a glycerol molecule
Made up from 3 carbon atoms
| Carbon atoms attached with a hydroxyl group (OH) and H atoms occupy remaining positions
68
Glycerol is aka
Propane 123
| Because it has three OH function groups
69
How many Ester bonds would be formed in a condensation reaction of a triglyceride
3
70
Fatty acids can either be
Saturated
| Unsaturated
71
Saturated fatty acids have what bonds
No double bonds
| No C=C
72
Saturated fatty acids contain how much hydrogen
The max amount
73
Saturated fatty acids are what at room temp
Solid (fats)
74
Unsaturated fatty acids contain what bonds
One or more double bonds
One or more C=C
(1 is monounsaturated
2 or more is polyunsaturated)
75
Unsaturated fatty acids contain how much hydrogen
Less
76
Unsaturated fatty acids are usually what at room temp
Liquid (oils)
77
What are phospholipids
They contain
2 fatty acids
1 glycerol molecule
1 phosphate group
78
Phosphate head
Polar - partially charged
| Hydrophilic - attracts water
79
Fatty acid tail
Not polar - not charged
| Hydrophobic- repels water temperature
80
Why do phospholipids arrange themselves in a bilayer
Inside the membrane is water
Outside the membrane is water
The heads must point outside of the membrane and inside it
The tails must point towards each other
81
What are monomers
Repeating units which make up polymers
82
What are proteins
Polymers made up of monomers called amino acids
83
What is an amino acid made of
An anime/amino group
A side chain/R group
A carboxyl group/carboxylic acid
84
What does an amine group contain
An amino group
| An acid group
85
How do 2 amino acids join together
```
An OH is lost from a carboxyl group
A H is lost from an amino group
They form water in a condensation reaction
They from a peptide bond
This creates a dipeptide molecule
```
86
What is a primary structure
The specific order of amino acids determined by DNA in a polypeptide chain
87
How do polypeptide chains differ
Although bonded in the same way
| Each amino acid has a different R group
88
What is the secondary structure
The folding of a polypeptide chain into an alpha helix or beta pleated sheet
89
How is the secondary structure held together
Hydrogen bonds
90
How do H bonds allow the secondary structure to be held together
Oxygen is electronegative
Nitrogen is electronegative
This makes hydrogen slightly electropositive
So H bonds form between NH and C=O groups
(Opposite charges pull them together)
91
What is the tertiary structure
The folding of a polypeptide chain into a compact globular 3D structure which is unique and specific
92
What are the bonds in the tertiary structure determined by
The amino acids ‘R’ groups
Polar - hydrophilic
Non polar - hydrophobic
93
Do all proteins have a tertiary structure
Nope
| Mostly enzymes and hormones do
94
How is a disulphide bridge bond formed in the tertiary structure
Can only be formed by the amino acid cysteine
| Hydrogen is removed from both R groups to form H2 in a process called dehydrogenation
95
How is an ionic bond formed in the tertiary structure
Formed by a positive (acidic) and a negative (basic) R group
96
How is a hydrogen bond formed in the tertiary structure
By a partially positive and partially negative R group
97
What is the quaternary structure
These consist of more than 1 polypeptide chain, which could all be the same or different
98
Do many proteins have a quaternary structure
No
99
Emulsion test for lipids
Crush seed with 1cm3 of ethanol
Then add water
Shake thoroughly
If a milky white emulsion forms, ethanol is present
100
Test for protein
Add biuret solution to sample
Shake
It should turn purple/lilac/mauve
