Carbohydrates,lipids Flashcards
1
Q
What elements do carbohydrates contain?
A
C, H, O
2
Q
The general formula for carbohydrates
A
Cx(H20)y
3
Q
Other names for carbohydrates
A
Saccharides, sugars
4
Q
What is a single sugar unit called?
A
Monosaccharide’s
5
Q
Examples of monosaccharides
A
Glucose
Fructose
Ribose
6
Q
Carbohydrates are the…
A
Source of all energy
7
Q
Where does glucose come from?
A
Comes from the sun- plants photosynthesise
8
Q
Formula for glucose
A
C6 H12 06
9
Q
What is a disaccharide?
A
2 monosaccharide’s joined together
10
Q
Example of a disaccharide?
A
Lactose, sucrose
11
Q
What is a polysaccharide?
A
When 2 or more monosaccharide’s join together to form a polymer
12
Q
Examples of a polyssccharide?
A
Glycogen, starch and cellulose
13
Q
What are the main monomers of a biologically important large carbohydrate?
A
Glucose
14
Q
Describe glucose?
A
Glucose is a monosaccharide built of six carbons therefore a hexose monosaccharide
15
Q
Which way are the carbons numbered in a molecular structure diagram?
A
Clockwise
16
Q
What is the difference between alpha glucose and beta glucose?
A
The OH group on carbon 1 is in the opposite position in beta, its been flipped
17
Q
Glucose molecules are…. +- and soluble in….
A
Polar
water
18
Q
Why are glucose molecules soluble in water and polar
A
This is from the hydrogen bonds that form in the OH group and water molecules.
19
Q
Why is it important glucose dissolves in water?
A
It is able to dissolve in the cytosol and be transported to where it is needed
20
Q
How do 2 glucose molecule join together
A
When the two alpha glucose molecules are side by side the two hydroxyl groups interact. This happens when bonds are broken and new bonds reform at carbons 1 and 4 on the glucose molecules- molecules now joined and created maltose
21
Q
What is removed when two alpha glucose molecules join together?
A
Two hydrogen atoms and an oxygen atom are removed from the glucose monomers and join to form water.
22
Q
What reaction takes place when two alpha glucoses join together?
A
condensation reaction as water is gained
23
Q
What covalent bond is formed between two glucose molecules?
A
Glycosidic bond
24
Q
What is a condensation reaction?
A
Where a water molecule is formed from one of the products reactions
25
What glycosidic bond does two glucose molecules make?1
1,4 glycosidic bond
26
What is maltose an example of?
Disaccharide
27
Name some hexose monosaccharides?
Fructose
| galactose
28
Describe fructose
Found in fruits, sweeter than glucose
29
what does
| fructose+ glucose make
Sucrose- cane sugar
30
What does galactose +glucose make
Lactose
31
Where is lactose found?
In milk and milk products
32
Fructose, glucose and galactose
| Sweetest to sweet
Fructose
Glucose
galactose
33
What are pentose monosaccharides
Sugars that contain 5 carbon atoms.
34
Name two important pentose sugars
Ribose in RNA nucleotides
| Deoxyribose in DNA nucleotides
35
What is starch made up of?
Many alpha glucose molecules that are joined together by glycosidic bonds to form the polysaccharide- starch
36
Where is glucose made and what is it stored as?
In plants as starch
37
Name two polysaccharides found in starch?
Amylose
| Amylopectin
38
Describe amylose
Formed by alpha glucose molecules joined together by 1-4 glycosidic bond
Long chains that twists to form a helix which is stablised by hydrogen bonds.
Therefore compact, less soluble
39
Describe Amylopectin
Made from a 1,4 glycosidic bond between alpha molecules but glycosidic bonds also seen on 1,6 carbons on two glucose molecules
Branching structure
insoluble
40
What is the energy storage molecule in starch?
Glycogen
41
Describe glycogen
Branches = more compact and less space is needed for storing it, which is important for mobile animals
compact
insoluble
42
What make glycogen compact?
The coiling of the polysaccharides
43
What benefit does glycogen have that speeds up adding or removal of molecules?
The free ends allows for molecules to be added, which speeds process up
44
Similarities of glycogen and amylopectin
Insoluble
branched
compact
45
What is glucose stored as in plants?
Starch
46
What is glucose stored as in animals/fungi?
Glycogen
47
Why do animals need glucose?
For respiration
48
How is glucose released after it has been stored as starch?
Undergoes hydrolysis reactions
49
What does hydrolysis require
Water
50
Beta glucose molecules are unable to join. Whys this?
The 1 and 4 carbon are too far from eachother to react
51
What do beta glucose molecules doso they can react?
Turns the alternative beta molecule upside down
52
Limitation from 2 beta glucose molecules joining together?
They are unable to coil = form straight chain
53
What straight chain does two beta glucose molecules make?
Cellulose
54
What bonds do hydrogen bonds make when forming cellulose
Microfibrils
55
What sugars are reducing sugars
Disaccharides and monosaccharide's
56
What does the term 'reducing sugar' mean?
Means it can donate electrons or reduce another chemical/molecule
57
What chemical test is used for a reducing sugar?
Benedicts test
58
How is the benedicts test carried out?
- Place sample in boiling tube (grind if not liquid)
- Add an equal amount of benedicts regeant
- Heat mixture gently in boiling water for 5 minutes
- if reducing sugar turns red
59
How do reducing sugars react with benedicts regeant?
reducing sugars react with copper ions in the benedicts reagent.
addition of electrons to the blue Cu+ ions, reducing them to red Cu+ ions.
60
What colour indicates a reducing sugar in the benedicts test?
Red precipitate
61
What doesn't react in the benedicts test?
reducing sugars- stays blue
62
What is a common non reducing sugar?
Sucrose
63
How do they get sucrose to be able to undergoes the benedicts test?
boil with hydrochloric acid and then warmed with benedicts solution. This is because the sucrose has been hydrolysed by the acid to glucose and fructose- which are reducing sugars
64
What is the iodine test for?
Starch
65
How do you carry the iodine test out?
Add a few drops of iodine, dissolved in potassium iodide solution= mixed with a sample. If solution changes the colour from yellow to purple, starch is present.
66
What colour does the solution change in the iodine test if theres starch
From yellow to purple
67
What are reagent strips used for?
testing for the presence of reducing sugars
68
Benefits of using reagent strips?
Also see concentration of sample from the colour coded chart
69
What is a colorimeter?
piece of equipment that quantitatively measures the absorbance of light by a coloured solution. The more concentrated the solution the less light will be transmitted
70
How is a colorimeter experiment carried out?
- Filter placed in colorimeter
- calibrated with water
- Benedicts test carried out
- resulting solutions filtered to remove precipitate
- % of each solution of glucose measured using the colorimeter
- Calibration curve plotted
71
What are biosensors?
use biological components to determine the presence and concentration of molecules like glucose
72
What is a lipid?
Molecules containing C,H,O
| Fats and oils
73
Describe a lipids polarity?
Non-polar molecules as the electrons on the outer shell that form the bonds are more evenly distributed than in polar molecules
Meaning there are no positive or negative areas
74
By lipids being non polar, what does this affect?
Insoluble in water
75
What are lipids also known as?
Macromolecules
76
How is a triglyceride made?
Combining a glycerol molecule with three fatty acids
77
What is a glycerol?
member of the group- alcohols
78
What group do fatty acids belong to?
Carboxylic acids, consisting of a carboxyl group and a hydrocarbon chain
79
Explain the reaction within a triglyceride
The hydroxyl group react,forming three water molecules and bonds between the fatty acids and the glycerol molecule. known as ester bonds-esterification
80
What bonds form between a glycerol and three fatty acids?
Ester bonds as esterification occurs
81
What is needed to break down a triglyceride?
Three water molecules so hydrolysis reaction can take place
82
What is a saturated fat
no double bonds present between carbon atoms
83
Example of a saturated fat?
Fatty acid chains
84
What is a unsaturated fat?
One or more double bond between carbon atoms
85
What is a mono-unsaturated
Only one double bond present
86
What is a polyunsaturated
More than one double bond present
87
What happens to the molecule if it is unsaturated?
Kinks/bends therefore cant be compact
| making it liquid
88
What type of triglyceride do plants contain?
Unsaturated
89
Benefits of unsaturated triglycerides
More healthy as normally in oils
90
What are the disadvantages to saturated fats
lead to coronary heart disease
| obesity
91
What are phosopholipids?
Modified triglycerides
92
What elements do phospholipids contain?
inorganic Phosphorus, C,H,O
93
Where is the inorganic phosphate found in the phospholipid
cytoplasm
94
Why are phospholipids soluble in water
As the phosphate ions have extra electrons therefore negatively charged = making it soluble
95
2/3 fatty acid chains only appear in the phospholipid, what replaces one of the chains
Phosphate group
96
Describe the structure of the phospholipid
Hydrophilic head
| Hydrophobic tail
97
How does a phospholipid react with water?
Form on rhe surface with the phosphate head in the water and the hydrophobic tail sticking out of the water- from this called surfactants
Also form a phospholipid bilayer-hydrophobic tail points in , protected from the water by the outer hydrophilic head.
98
what is a sterol
A type of lipid
99
What is the structure of a sterol?
Complex alcohol molecule
4 carbon rings structure with a hydroxyl group at one end.
dual hydro-philic/phobic characteristics
100
Describe the polarity of a sterol
Hydroxyl group is polar, therefore hydrophilic
| rest of the molecule hydrophobic
101
Example of a sterol/
Cholesterol
102
Where does the body manufacture cholesterol
Liver and intestines
103
What is the role of cholesterol
Formation of cell membrane
becoming positioned between phospholipids with the hydroxyl group at the periphery of the membrane -adding stability to membrane and regulates the fluid by keep temperatures low
104
What is manufactured by cholesterol
Vitamin D
Bile
Steroid hormones
105
As lipids are non-polar, what are their biological roles?
Membrane formation
hormone formation
Electrical insulation
Waterproofing-e.g. birds feathers
106
Lipids- triglycerides are good at what?
storing energy
107
In terms of energy, where are lipids stored
Under the skin
108
What are the advantages of lipids like triglycerides, being stored under the skin
thermal insulation
cushioning to protect vital organs
Buoyancy
109
What test is use to identify lipids?
Emulsion test
110
How is the emulsion test for lipids carried out?
Sample mixed with ethanol
mixed with water then shaken
If white emulsion forms on top= lipid present
if stays clear no lipid
