Brainscape's Knowledge GenomeTM

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


See full index

OCR Biology AS H020 > Biological Molecules > Flashcards

Biological Molecules Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is a polar molecule?

A

A molecule that contains unsymmetrical bonds where there is a difference in electronegativity leading to dipoles with positive and negative charges.

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

Water is a ______ molecule and forms ______ bonds…

A

Polar, hydrogen.

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

What is the bonding angle in water?

A

104.5

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

Why does water have a unusually large BP?

A

The hydrogen bonds require large amounts of energy to break.

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

Why is ice less dense than water?

A

The molecules spread out forming 4 hydrogen bonds creating a giant, rigid but open structure.

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

Water has cohesive/adhesive properties, explain what this means…

A

Cohesion - the sticking together of particles of the same substance.
Adhesion - the action or process of adhering to a surface or object.

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

Give an example of waters cohesive properties…

A

In the xylem.

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

What property of water allows pond skaters’ to walk on it’s surface?

A

Surface tension.

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

State 2 ways that water is useful as a solvent…

A

Transport medium, reaction medium.

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

The effects of cohesion and adhesion means water can exhibit the property of _____ ?

A

Capillary action.

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

What is capillary action?

A

Water can rise up a narrow tube against the force of gravity.

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

What term describes water ‘buffering temperature changes’?

A

Coolant.

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

Why is it important that water has a high SHC?

A

Maintains a stable constant environment.

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

When water freezes it forms an insulating layer above, why is this important?

A

It prevents further freezing and insulates life below.

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

What is a monosaccharide?

A

A single sugar unit.

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

What is a carbohydrate?

A

Molecules that only contain the elements carbon, hydrogen and oxygen, the literal meaning is ‘hydrated carbon’.

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

What is the general formula of a carbohydrate?

A

Cx(H20)y

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

Name 4 monosaccharides…

A

Glucose, fructose, ribose, galactose.

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

Name 2 disaccharides…

A

Lactose, sucrose.

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

Name 3 polysaccharides…

A

Glycogen, cellulose, starch.

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

What is the molecular formula of glucose?

A

C6H12O6.

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

Why is glucose considered a hexose monosaccharide?

A

It is a single sugar unit with 6 carbons in it’s structure.

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

How are carbons numbered in carbohydrates?

A

Clockwise beginning with the carbon to the right of the oxygen in the ring.

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

Where is the OH (hydroxyl) group in alpha glucose?

A

Below.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where is the OH (hydroxyl) group in beta glucose?

A

Above.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In a glucose molecule, from carbon 2 onwards, what is the placement of OH groups?

A

BAB.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

In a glucose molecule what is the extra group?

A

CH2OH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Glucose + Fructose =

A

Sucrose + H20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Galactose + Glucose =

A

Lactose + H20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What type of bond is formed between two monosaccharides?

A

Glycosidic bond.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What type of bond is formed between two glucose monomers?

A

1,4 glycosidic bond.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What type of reaction takes place when two monosaccharides join?

A

Condensation reaction producing water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Glucose + Glucose =

A

Maltose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Place the following sugars in order of sweetness (glucose, galactose, fructose)…

A

Fructose, glucose, galactose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Give 2 examples of pentose monosaccharides…

A

Ribose, deoxyribose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is starch made up of?

A

Alpha glucose monomers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the two forms of starch?

A

Amylose and amylopectin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How is amylose formed?

A

A condensation reaction between alpha glucose molecules forming 1,4 glycosidic bonds ONLY.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Describe the structure of amylose…

A

The chain twists to forma helix which is stabilised by hydrogen bonds, it is unbranched.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Name two properties of glucose molecules and why they are important…

A

Polar and soluble in water, can be dissolved in the cytosol of cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Explain the properties of amylose…

A

The helix makes the polymer more compact and less soluble.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How is amylopectin formed?

A

A condensation reaction between alpha glucose molecules forming 1,4 glycosidic bonds and branched 1,6 glycosidic bonds every 25 subunits.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are the properties of amylopectin?

A

Amylopectin is branched, insoluable and compact. Glucose can be stored or released quickly by hydrolysis due to an abundance of free ends.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

How are carbohydrates broken down?

A

Hydrolysis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the equivalent energy store to starch in animals and fungi?

A

Glycogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the difference between amylopectin and glycogen?

A

Glycogen has more branches so is more compact wich is important and animals are mobile.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

How is cellulose formed?

A

Alternate beta glucose molecules turned upside down form 1,4 glycosidic bonds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Why is hydrolysis of carbohydrates important?

A

Respiratory demands.

49
Q

Describe the structure of cellulose…

A

Straight chain, unbranched.

50
Q

What is formed when cellulose molecules form hydrogen bonds with one another?

A

Microfibrils.

51
Q

Microfibrils form _____ ?

A

Macrofibrils.

52
Q

Macrofibrils form _____ ?

A

Fibres.

53
Q

What are the properties of cellulose fibres?

A

Strong and insoluable.

54
Q

What are cellulose fibres used for?

A

Making cell walls.

55
Q

In our diet, what does cellulose fibre do?

A

Form roughage necessary for a healthy digestive system.

56
Q

What is a reducing sugar?

A

A monosaccharide (sometimes di) that donate electrons/reduce molecules.

57
Q

What is Benedict’s reagent?

A

Alkaline aq solution of Copper (II) Sulfate.

58
Q

Describe Benedict’s test for reducing sugars…

A

Grind up sample and blend with water in not liquid. Add an equal volume of BR. Heat the mixture gently in a water bath for 5 minutes.

59
Q

What happens in a +ve Benedict’s test?

A

Blue Cu2+ ions are reduced to brick red Cu+ ions forming a precipitate.

60
Q

Describe the colour changes and how they represent the % of reducing sugar during Benedict’s test… (qualitativity)

A 
Blue - None
Green - Very low
Yellow - Low
Orange - Medium
Red - High
61
Q

How can a non-reducing sugar show a +ve result in Benedict’s test?

A

Boil it with HCl (hydrolyse it) first.

62
Q

What is the iodine test?

A

Used to detect the presence of starch. Iodine dissolved in potassium iodide is mixed with a sample. A colour change from yellow/brown to purple/black indicate the presence of starch.

63
Q

What are reagent strips used for?

A

Test for the presence of reducing sugars, they use a colour coded chart to measure the concentration.

64
Q

What elements do lipids contains?

A

Carbon, hydrogen, oxygen and phosphorus.

65
Q

Fats are ____ and oils are ____ at RTP?

A

Solid, liquid.

66
Q

Lipids are large complex molecules known as?

A

Macromolecules.

67
Q

What are the properties of lipids?

A

Non polar and insoluble in water.

68
Q

What is a triglyceride made up of?

A

1 glycerol (alcohol) molecule and 3 fatty acids (carboxylic acids).

69
Q

What us the functional group of a carboxylic acid?

A

-COOH

70
Q

How are triglycerides formed?

A

3 OH groups from the glycerol molecule react with the COOH groups from 3 carboxylic acids forming 3 ester bonds and 3 water molecules during esterification.

71
Q

Esterification is an example of what type of reaction?

A

Condensation.

72
Q

What is a saturated fatty acid?

A

No C=C double bonds present.

73
Q

What is an unsaturated fatty acid?

A

A fatty acid that contains one (monounsaturated) or more (polyunsaturated) C=C double bonds in it’s chain.

74
Q

What effect does a C=C double bond have on a fatty acid chain?

A

It causes a kink in the chain so they cannot pack as closely together leading to the fatty acid being liquid at RTP (oil not fat).

75
Q

What are phospholipids?

A

Modified triglycerides containing a phosphate group (PO4 3-) instead of a fatty acid.

76
Q

Explain the charges on a phospholipid…

A

A -ve charged head and a non charged tail.

77
Q

Why are phospholipids are hydrophobic?

A

Their non-polar tails are repelled by water.

78
Q

Why are phospholipids hydrophilic?

A

The charged heads interact and are attracted to water.

79
Q

Name 2 structures phospholipids can form…

A

Bilayers and monolayers.

80
Q

Why are phospholipids described as surfactants (surface active agents?

A

They form monolayers with their hydrophilic heads in the water and hydrophobic tails out of the water.

81
Q

Sterols are also known as?

A

Steroid alcohols.

82
Q

Explain a property of sterols…

A

Dual hydrophobic/philic characteristics. OH group is polar hence hydrophilic and the rest of the molecule is hydrophobic.

83
Q

What structure are sterols based on?

A

4 carbon ring structure with a OH group at one end.

84
Q

Name a sterol…

A

Cholesterol.

85
Q

Where is cholesterol primarily manufactured?

A

Liver and intestines.

86
Q

What role does cholesterol play in cell membranes?

A

Adds stability and regulates their fluidity.

87
Q

Give 3 things manufactured using cholesterol…

A

Bile, vitamin D and steroid hormones.

88
Q

What are the 8 biological roles of lipids?

A

Membrane formation, hormone production, electrical insulation, waterproofing, thermal insulation, cushioning, buoyancy and energy stores.

89
Q

How does the emulsion test work?

A

The sample is mixed with ethanol then water and shaken. If a white emulsion forms a lipid is present.

90
Q

Describe the 3 groups coming off a carbon atom in an amino acid.

A

Hydrogen, carboxyl group, amine group, R group.

91
Q

What are peptides?

A

Polymers made up of amino acid molecules.

92
Q

What are proteins?

A

One or more polypeptides arranged as complex macromolecules.

93
Q

What elements do proteins contain?

A

CHON

94
Q

How many amino acids are there?

A

20

95
Q

How many essential amino acids are there?

A

9

96
Q

How many non-essential amino acids are there?

A

5

97
Q

How many conditionally essential amino acids are there?

A

6

98
Q

How do amino acids join to form a dipeptide?

A

A peptide bond is formed between the carboxyl (OH) and amine groups (H) producing water.

99
Q

What type of reaction is the formation of a dipeptide?

A

Condensation.

100
Q

What is the primary structure?

A

The amino acid sequence.

101
Q

What bonds are involved in the primary sequence?

A

Peptide bonds.

102
Q

What determines the primary sequence?

A

DNA

103
Q

What bonds are involved in the secondary structure?

A

Hydrogen bonds

104
Q

What structures can be formed in the secondary structure?

A

Alpha helix and beta pleated sheet.

105
Q

What bonds are involved in the tertiary structure?

A

Hydrophobic/philic interactions between polar/non-polar R groups. Hydrogen bonds. Ionic bonds, Disulfide bridges.

106
Q

What is the quaternary structure?

A

The association of individual proteins (subunits)

107
Q

Give 3 examples of quaternary proteins…

A

Haemoglobin, insulin, enzymes.

108
Q

Describe globular proteins…

A

Compact, water soluble, spherical proteins with hydrophobic groups on the inside.

109
Q

Give an example of a globular protein…

A

Insulin, a blood glucose concentration hormone, it is transported in the bloodstream and has a specific shape that fits receptors on cell surface membranes.

110
Q

What are conjugated proteins?

A

Globular proteins with prosthetic groups (cofactors).

111
Q

What is an example of a prosthetic group?

A

Haem (Fe2+) in haemoglobin and catalase.

112
Q

Elaborate on the structure of haemoglobin and how it relates to it’s function.

A

Made of 4 subunits, 2 alpha, 2 beta. There are 4 haem groups which enable O2 to be picked up.

113
Q

State 2 conjugated proteins…

A

Haemoglobin and catalase.

114
Q

Elaborate on the structure of catalase…

A

A quaternary protein with 4 haem groups allowing it to interact with H2O2 and speed up it’s breakdown as it is a toxic by product of metabolism.

115
Q

What are the properties of fibrous proteins?

A

Formed from long, insoluble molecules as many R groups are hydrophobic. They contain a limited range of R groups which are usually small, the amino acid sequence is repetitive, they are strong,

116
Q

Name 3 fibrous proteins…

A

Keratin, elastin and collagen.

117
Q

Describe the fibrous protein keratin…

A

High sulphur (cyestine) content forming strong disulfide bridges resulting in strong, inflexible, insoluble molecules. The degree of bridges determines the flexability.

118
Q

Describe the fibrous protein elastin…

A

Quaternary protein made from stretchy tropoelastin molecules, they are present in elastic fires.

119
Q

Describe the fibrous protein collagen…

A

A connective tissue found in skin, tendons, ligaments and the nervous system. Made up of 3 polypeptides wound like a rope giving it flexibility.

OCR Biology AS H020 (10 decks)

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