Week 4 Flashcards
(127 cards)
1
Q
What are the general functions of carbohydrates and lipids?
A
Energy stores
Metabolic intermediates
Help form DNA and RNA
Form structural elements of bacterial and plant cell walls
2
Q
Draw the structure of 2-Deoxyribose
A
-
3
Q
Draw the structure of Ribose
A
-
4
Q
What is the numerical formula of a carbohydrate ?
A
(CH2O)n where n is 3 or greater.
5
Q
What is the simplest unit of a carbohydrate called?
A
Monosaccharide
6
Q
What is a monosaccharide?
A
The simplest unit of a carbohydrate and the simplest form of a sugar. Only one unit
7
Q
Name the 3 monosaccharides.
A
Glucose
Fructose
Galactose
8
Q
How many hydroxyl groups must monosaccharides contain at least ?
A
2
9
Q
Describe the taste of monosaccharides
A
Sweet
10
Q
How are monosaccharides classified?
A
They are classified into Aldoses or Ketoses depending on whether contain a aldehyde or ketone group
11
Q
What are the 2 classes of monosaccharides?
A
Aldoses
Ketoses
12
Q
What are the most simple types of monosaccharides and how many carbons do they contain?
A
Trioses
3
13
Q
What is an oligosaccharide ?
A
A carbohydrate chain which contains 2 to 20 monosaccharides.
14
Q
What is a polysaccharide ?
A
A carbohydrate chain which contains more than 20 monosaccharides.
15
Q
What are carbohydrates often called?
A
Glycans
16
Q
What are Glycans?
A
Carbohydrate chains
17
Q
What are the 2 types of Glycan carbohydrate chain?
A
Homoglycan
Heteroglycan
18
Q
What is a homoglycan carbohydrate chain?
A
Carbohydrate polymer with identical sugar subunits
19
Q
What is a heteroglycan carbohydrate chain?
A
A carbohydrate polymer made up of different sugar (monosaccharide) units.
20
Q
What are aldoses in terms of carbohydrates?
A
Sugars containing an aldehyde group and at least 2 hydroxyl groups.
21
Q
What is the simplest also carbohydrate?
A
Glyceraldehyde
22
Q
What are ketoses in terms of carbohydrates?
A
Sugars that contain a ketone group and at least 2 hydroxyl groups.
23
Q
What is the simplest ketoses carbohydrate?
A
Dihydroxyacetone
24
Q
What is the general formula for aldehydes ?
A
RCHO
25
What is the general formula for ketones?
RCOR'
26
What group do both aldehydes and ketones contain?
Carbonyl
27
Draw the general structure of a ketone group
-
28
Draw the general structure of an aldehyde group
-
29
What type of monosaccharides have stereoisomers?
Chiral monosaccharides
30
What types of monosaccharides can cyclise?
Any group of monosaccharides with 4 or more carbon atoms.
31
How many carbon atoms must be present in a monosaccharide group for it to cyclise?
4
32
How do groups of monosaccharides cyclise?
The aldehyde or ketone group of one sugar reacts with the hydroxy group of another sugar to form a closed ring.
33
What are disaccharides ?
2 monosaccharides joined by a glycosidic bond.
34
What 2 monosaccharides form maltose disaccharide?
2 x alpha glucose
35
What 2 monosaccharides form Sucrose disaccharide?
Glucose and Fructose
36
What 2 monosaccharides form Lactose?
Galactose and Glucose
37
What are the 2 forms of a glycosidic bond?
Alpha and beta
38
What is a glucoside?
A glycoside derived from glucose only.
39
What is a glycoside ?
Any group of sugar derivatives, which on hydrolysis produces a sugar and one or more other substances.
40
Name some important polysaccharides.
Glycogen
Starch
Dextran
Cellulose
41
What is the main function of glycogen as a polysaccharide?
It aids glucose storage in mammals.
42
Where is alot of glycogen present in the body?
Liver and muscle cells
43
Describe the structure of Glycogen.
Large, branched, 1-4 alpha glycosidic bonds, approximately every 10 units a branch chain occurs due to 1-6 alpha glycosidic bonds.
44
What type of glycosidic bonds are present in glycogen?
1-4 alpha
| 1-6 alpha
45
What is the main purpose of starch?
Stores energy in plants
46
What are the 2 forms of starch?
Amylose and amylopectin
47
What is the main difference between the structures of amylose and amylopectin?
Amylose is straight chained and amylopectin is branched.
48
What is the main purpose of dextran?
It is used to treat hypovolemia by restoring blood plasma lost through severe bleeding.
49
What is hypovolemia?
A decrease in the volume of blood plasma due to excessive bleeding.
50
What is the main purpose of cellulose?
Helps structure the cell walls of plans.
51
Describe the solubility of cellulose.
Insoluble in water
52
Is cellulose branched?
No
53
What type of glycosidic bonds does cellulose contain?
1-6 glycosidic bonds
54
Which form of starch is more abundant in plants?
Amylopectin
55
What type of glycosidic bonds does amylose contain?
1-4 alpha
56
What type of glycosidic bonds does amylopectin contain?
1-4 alpha
| 1-6 alpha
57
What enzymes can be used to hydrolyse amylose completely ?
a amylase and b amylase hydrolyse amylose fully.
58
What enzymes can be used to hydrolyse amylopectin?
a amylase and b amylase can only partially hydrolyse amylopectin.
59
What colour does amylose appear when stained with iodine?
Dark blue / black
60
What colour does amylopectin appear when stained with iodine?
Reddish brown
61
Is amylose or amylopectin more soluble in water?
Amylopectin
62
Does amylose or amylopectin form a gel when hot water is added?
Amylopectin
63
What are Glycoconjugates?
Carbohydrate derivatives which are linked to proteins or peptides.
64
What are proteoglycans?
Complexes of proteins and glycosaminoglycans found in the connective tissue of mammals.
65
Where are proteoglycans found?
The connective tissue of mammals
66
What are peptidoglycan?
Polysaccharides linked to small peptides.
67
Describe the solubility of lipids in water.
Water insoluble
68
When are lipids sometimes soluble?
In non-polar, organic solvents.
69
Describe the hydrophobicity/ hydrophilicity of all lipids.
They are either hydrophobic or amphipathic.
70
What are the simplest form of lipids called?
Fatty acids
71
What is the general formula for fatty acids?
RCOOH
| Where R is a simple hydrocarbon chain.
72
What does the 'R' mean in the general formula for fatty acids.
A simple hydrocarbon chain
73
What is the terminal group of all fatty acids?
Carboxyl group
74
What are the main uses of fatty acids?
They are used as fuel in specific cell types during starvation, following exercise and in diabetes mellitus.
They act as precursors to signalling molecules.
75
What are saturated fatty acids.
Only single bonds present.
76
Describe the state of saturated fatty acids at 22 degrees Celsius.
Waxy solid
77
What are monounsaturated fatty acids.
Contain one double bond
78
Describe the state of unsaturated fatty acids at 22 degrees celsius.
Liquid
79
What are polyunsaturated fatty acids?
They contain more than one double bonds.
80
What is a cis unsaturated fatty acid?
Surrounding the carbon carbon double bond, both hydrogen molecules are on the same side. (Above or below).
81
What is a trans unsaturated fatty acid?
Surrounding the carbon carbon double bond, the hydrogen molecules are on opposite sides of the bond ( one above and one below).
82
How does the saturation of a fatty acid affects its melting point?
The more saturated a fatty acid, the greater its melting point.
83
How does the length of a fatty acid affect its melting point?
The longer a fatty acid, the higher its melting point.
84
What are the key roles of Triacylglycerols?
They store fatty acids in the adipose tissue.
Insulation.
Transport dietary and synthesised fatty acids around the body via protein complexes.
85
Describe the polarity of each section of a phospholipid.
Fatty acid tails are hydrophobic and therefore non-polar.
Phosphate heads are polar and therefore hydrophilic
86
What is the importance of labelling carbons in a sugar with a number?
These helps identify the direction of the sugar phosphate backbone of a molecule and therefore helps find its function.
87
How can sugars be identified by their names?
They frequently have names which end in -ose.
88
What is the functional groups of Aldehydes?
-RCHO
89
What is the functional groups of ketones?
-RCOR'
90
What is R' in terms of a molecules structure?
A second variable region (attached to the central carbon molecule).
91
What causes glyceraldehyde to be chiral?
It has a single asymmetric carbon.
92
What are FISHER projections used for?
They show a 3D molecule in a 2D representation.
93
In cyclisation of monosaccharides, what bonding occurs and where to form the ring structure?
The hydroxyl group of the second to last carbon undergoes an intramolecular reaction with the carbonyl group of the aldehyde or ketone of the monosaccharide.
94
What is the produce of aldose cyclisation ?
Hemiacetal
95
What is a hemiacetal?
A ring structure formed by the cyclisation of an aldose monsaccharide.
The addition of an alcohol to an aldehyde.
96
What is the product of ketone cyclisation?
Hemiketal
97
What is a hemiketal?
The ring product formed by cyclisation of a ketose monosaccharide.
An alcohol is added to a ton.
98
What type of glycosidic bonds does Lactose have?
1-4
99
What orientation type does lactose have?
Beta
100
What type of glycosidic bonds does maltose have?
1-4
101
What type of orientation does Maltose have?
Alpha
102
What type of glycosidic bonds does sucrose have?
1-2
103
What orientation type does sucrose have?
Alpha
104
How can an alpha (glucose) molecule be identfied?
OH below H
105
How can a beta (glucose) molecule be identified?
OH above H
106
What groups must a hemiacetal group contain?
A carbon atom with a hydroxyl group and an alkyl group attached.
107
In what type of sugars is a hemiacetal group present?
Cyclic sugars
108
What bonds join monosaccharide units?
Glycosidic
109
What are the 4 different distinct polymers that Glucose can form?
Amylose, Amylopectin, Cellulose, Glycogen
110
What % of plant starch is Amylose?
20%
111
What % of plant starch is Amylopectin?
80%
112
what enzyme is used to break starch down into glucose in the saliva?
Amylase
113
What type of organisms can break down cellulose?
Ruminants such as cows
114
What are ruminant animals?
A mammal whose digestion works by chewing partly digested foods a second time in order to soften them.
115
What food groups must be eaten by humans and contains alot of cellulose?
Fibre
116
What is meant by 'fibre rich' foods?
Food that contain alot of cellulose
117
What is the purpose of cellulose in the human body?
It helps ensure functional digestion is occurring and therefore helps avoid constipation.
118
What is type 1 diabetes?
Insulin isn't produced by the body
119
What is type 2 diabetes?
Too little insulin is produced to meet the demand to remove high levels of glucose in the blood plasma
120
What is the general purpose of insulin in the body?
To stimulate the transport of Glucose out of the blood plasma to be stored as Glycogen in the liver and muscle cells when blood glucose levels are too high.
121
What is hyperglycaemia?
Elevated blood Glucose levels
122
What are the symptoms f hyperglycaemia ?
Thirst, frequent urination, blurred vision, heart disease, kidney damage, circulation problems, nerve damage to feet.
123
Why can diabetes often cause blurred vision ?
The high blood pressure can change the shape of the lenses of the eyes.
124
Why can prolonged hyperglycaemia lead to weight loss?
The body tries to remove excess glucose via the urine.
125
Name the main cause of Type 1 diabetes.
Auto-immune disease
126
What are the main causes of type 2 diabetes?
Obesity
| Ethnic origin
127
How does an auto-immune disease cause diabetes type 1?
The bodies immune system attacks the beta cells of the islets of langerhans of the pancreas so no insulin can be produced.
