Brainscape's Knowledge GenomeTM

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


See full index

Biology > 1a. BIOLOGICAL MOLECULES > Flashcards

1a. BIOLOGICAL MOLECULES Flashcards

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

Define polarity

A

An uneven distribution of electrons in a covalent bond

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

Describe the polarity in a water molecule

A

The hydrogen atoms are polar positive and the oxygen atom is polar negative

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

Describe how hydrogen bonds are created between water molecules

A

The polar positive hydrogen atoms in one molecule are attracted to the polar negative oxygen atoms in another molecule.

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

Recall the five properties of water that make it important for living things

A

High specific heat capacity
High latent heat
Metabolite
Universal solvent
Cohesive

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

Explain how having a high latent heat of vaporisation makes water important for organisms

A

It provides a cooling effect through evaporation

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

Explain how being a metabolite makes water important for organisms

A

It acts as a metabolite in condensation and hydrolysis reactions

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

Explain how being a universal solvent makes water important for organisms

A

It transports substances and allows reactions to occur

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

Explain how being cohesive makes water important for organisms

A

It supports columns of water

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

Explain how having a high specific heat capacity makes water important for organisms

A

Because water can buffer changes in temperature

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

Explain how water acts as a temperature buffer in cells

A

Water has a high specific heat capacity therefore it absorbs a lot of energy before the temperature increases

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

Why are biological molecules able to dissolve in aqueous solutions?

A

Most biological molecules are also polar

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

Explain how water moves as a continuous stream in transport vessels

A

Water is cohesive therefore the water molecules are attracted to each other

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

Which ion reduces pH in living organisms?

A

H+

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

Which ion is a component in Haemoglobin?

A

Fe2+

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

Which ion is involved in the co-transport of glucose and amino acids?

A

Na+

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

Which ion is a component of DNA and RNA?

A

PO4 3-

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

What is a nucleotide?

A

The basic building block of nucleic acids

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

Describe the three-part structure of a nucleotide

A

All nucleotides are made up of phosphate, a sugar and a nitrogenous base

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

Describe the structure of ATP

A

One ribose sugar, adenine, and three phosphtes

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

Which type of reaction occurs when phosphate groups are removed from ATP?

A

Hydrolysis

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

Which type of reaction occurs when phosphate groups are added to ADP?

A

Condensation

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

Why is ATP not a good long term energy store?

A

It is unstable over long periods of time

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

How ATP not being a good long term energy store overcome?

A

Your body uses large molecules as stores of energy, e.g. lipids and carbohydrates

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

Name five energy requiring processes that use ATP

A

Metabolic processes
Movement
Active transport
Secretion
Activation of molecules

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

Explain why its important that ATP only releases energy in small amounts

A

If large amounts of energy were released at once, it would increase the temperature of the cell and denature proteins

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

Describe four ways ATP is adapted for its function

A

It is small & dissolves in aqueous solutions
It releases energy instantaneously and in small amounts
It’s easily reformed from ADP
Pi can phosphorylate other molecules

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

Explain why ATP being small and dissolving in aqueous solutions helps it carry out its function

A

It means it’s easily transported

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

Explain the function of Pi phosphorylating another molecule

A

The Pi changes the molecule’s shape and lowers it’s activation energy

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

Define metabolism

A

The sum of all chemical reactions in the organism

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

Recall the two types of metabolism

A

Anabolic and catabolic

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

Define anabolic reactions

A

Reactions that build up smaller molecules into larger molecules, which requires energy

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

Give an example of anabolic reactions

A

Photosynthesis

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

Define catabolic reactions

A

Reactions that break down larger molecules into smaller molecules, which releases energy

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

Give an example of catabolic reactions

A

Respiration, protein synthesis

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

State the four most common elements in biological molecules

A

Carbon
Hydrogen
Oxygen
Nitrogen

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

State how many bonds each comment element in biological molecules makes

A

Carbon = 4
Hydrogen = 1
Oxygen = 2
Nitrogen = 3

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

Recall the five types of interactions within biological molecules

A

Ionic, covalent, disulphide bridges, hydrophilic/hydrophobic interactions, hydrogen bonds

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

Describe ionic bonding

A

Electrostatic attraction between a metal and a non-metal

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

Describe covalent bonding

A

The sharing of electrons between two non-metal elements

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

Describe disulphide bridges

A

Bonding between two sulphur atoms

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

Describe Hydrogen bonding

A

The polar positive hydrogen atoms in one molecule are attracted to the polar negative atoms in another molecule.

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

Describe hydrophilic / hydrophobic interactions

A

Hydrophilic groups dissolve in aqueous solutions, hydrophobic groups dissolve in organic solutions

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

Define a condensation reaction

A

Joining 2 molecules, creating a chemical bond and removing a molecule of water

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

Define a hydrolysis reaction

A

Breaking a chemical bond between 2 water molecules and involving the use of a water molecule

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

Recall the general formula for carbohydrates

A

(CH2O)n

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

Describe how to number the carbons within a monosaccharide

A

Clockwise, starting with the carbon after the oxygen in the ring

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

Name three hexose monasaccharides

A

Glucose, fructose and galactose

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

Name two pentose monasaccharides

A

Ribose and deoxyribose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Name the two structural forms of glucose

A

Alpha and beta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Explain the difference between alpha and beta glucose

A

In alpha glucose, the OH group on carbon 1 is pointing down, whereas in beta glucose, the OH group on carbon 1 is pointing up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Draw a molecule of alpha glucose

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Draw a molecule of beta glucose

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Name the type of bond within a di/polysaccharide

A

Glycosidic bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Describe how a 1, 4 - glycosidic bond is formed between two glucose molecules

A

OH from one glucose and the adjacent H from another are removed as a molecule of water. A bond forms between carbon 1 and carbon 4 with an oxygen atom in between

55
Q

Name the disaccharide containing two alpha glucose

A

Maltose

56
Q

Name the disaccharide containing glucose and fructose

A

Sucrose

57
Q

Name the disaccharide containing galactose and glucose

A

Lactose

58
Q

Recall the formula for disaccharides

A

C12H22O11

59
Q

Draw a molecule of maltose

A
60
Q

Recall the three polysaccharides

A

Starch, glycogen and cellulose

61
Q

Describe the function of starch

A

Storage of glucose in plants

62
Q

Describe the structure of starch

A

A polymer of many alpha glucose monomers joined with 1,4 glycosidic bonds in a chain, with branches formed by 1,6 glycosidic bonds. It is coiled.

63
Q

Describe the function of glycogen

A

Storage of glucose in animals

64
Q

Describe the structure of glycogen

A

A polymer of many alpha glucose monomers, joined with 1,4 glycosidic bonds, many branches formed by 1,6 glycosidic bonds. It is coiled.

65
Q

Explain why glycogen is more branched than starch

A

Animals move therefore they need a faster release of glucose for respiration. Many branches means more free ends, so more glucose can be removed at once for respiration

66
Q

Explain why the coiled structure of starch and glycogen important for their function?

A

It makes them compact, this means that many glucose molecules can be stored in a small area

67
Q

Why is it important for starch and glycogen to be insoluble?

A

So they do not affect the water potential of the cell

68
Q

Why is it important for starch and glycogen to be large molecules?

A

So they cannot cross the cell membrane

69
Q

State which monosaccharides cellulose is made from

A

Beta glucose

70
Q

Describe the structure of one cellulose chain

A

Long straight chain of beta glucose with every other beta glucose is inverted. No branches.

71
Q

Describe the structure of a cellulose fibre

A

Chains of cellulose join by many hydrogen bonds to form a microfibril, many microfibrils join with crosslinks to make a macrofibril, many macrofibrils join with crosslinks to form a fibre

72
Q

Describe the function of cellulose

A

To strengthen cell walls in plants

73
Q

Describe the properties of cellulose

A

Insoluble, strong, difficult to break down

74
Q

Describe the importance of hydrogen bonds in cellulose

A

One hydrogen bond alone is weak, many hydrogen bonds together are very strong. This strengthens cell walls

75
Q

Define a lipid

A

Any molecule that is soluble in an organic solvent (e.g. alcohol)​

76
Q

Name the two main types of lipid

A

Triglycerides and phospholipids

77
Q

Recall the five uses of lipids in the body

A

Formation of membranes​
Source of energy​
Waterproofing​
Insulation​
Protection

78
Q

Name the two types of membranes lipids are used to create

A

Cell surface membranes and organelle membranes

79
Q

Give two examples of how lipids are used for waterproofing in organisms

A

A leaf’s waxy cuticle and skin oils

80
Q

Give two ways lipids are used for insulation in organisms

A

Thermal insulation and electrical insulation around neurones

81
Q

Describe how lipids are used for protection in organisms

A

They are stored around delicate organs

82
Q

Describe the structure of a triglyceride

A

One glycerol and three fatty acids held together by three ester bonds

83
Q

Draw a triglyceride (the tails can be any length greater than three carbons long)

A
84
Q

Name the reaction that creates a triglyceride

A

Esterification (& condensation)

85
Q

How many molecules of water are produced when one triglyceride is formed?

A

Three

86
Q

Why are fatty acids called carboxylic acids?

A

Because they contain a COOH (carboxyl) group

87
Q

Describe the structure of a phospholipid

A

A phosphate head and two fatty acid chains

88
Q

State which part of a phospholipid is hydrophilic and hydrophobic

A

Head (phosphate) is hydrophilic, tails (fatty acids) are hydrophobic

89
Q

Describe the structure of a phospholipid bilayer

A

Many phospholipids sit next to one another in a layer. There are two layers. The hydrophobic tails face towards each other, and the hydrophilic heads dissolve in the surrounding aqueous solutions.

90
Q

Explain the purpose of a phospholipid bilayer

A

Separate two aqueous environments

91
Q

Name the two types of fatty acid chain found in lipids

A

Saturated and unsaturated

92
Q

Describe the difference in structure between saturated and unsaturated fatty acids

A

Saturated fatty acids have only single C-C bonds (so are straight chains), unsaturated fats have one or more double C-C bonds (are therefore kinked/bent)

93
Q

What state of matter are fats and oils at room temperature?

A

Fats are solid at room temperature and oils are liquid at room temperature

94
Q

Do fats contain saturated or unsaturated fatty acid chains?

A

Saturated

95
Q

Do oils contain saturated or unsaturated fatty acid chains?

A

Unsaturated

96
Q

Explain why fats are solid at room temperature

A

The fatty acids are saturated and are therefore straight chains. There are stronger intermolecular forces beween triglyceride molecules. Therefore more energy is required to break them.

97
Q

Explain why oils are liquid at room temperature

A

The fatty acids are unsaturated and are therefore kinked chains. There are weaker intermolecular forces beween triglyceride molecules. Therefore less energy is required to break them.

98
Q

Explain why lipids are an excellent store of energy

A

They contain a high number of carbon to hydrogen bonds, therefore a lot of energy is released when the bonds are broken​.

99
Q

Why can lipids store a lot of energy in a small space?

A

They have a low mass to energy ratio

100
Q

Why do lipids not affect the water potential of a cell?

A

They are insoluble

101
Q

How many naturally occurring amino acids are there?

A

20

102
Q

Describe how amino acids give us indirect evidence for evolution

A

Proteins in all living organisms are made up of the same 20 amino acids

103
Q

Describe the basic structure of an amino acid

A

Amino group (NH2), carboxyl group (COOH), R group (varies), Hydrogen

104
Q

Draw the general structure of an amino acid

A
105
Q

Describe, referring to the groups, how two amino acids bond to make a dipeptide

A

The amine group on one amino acid bonds to the carboxyl group on the other amino acid. OH from carboxyl group and H from the amino group are removed (to form one water molecule) then the carbon and nitrogen join to form a peptide bond.

106
Q

Draw a dipeptide

A
107
Q

Name the four levels of protein structure

A

Primary, secondary, tertiary, quaternary

108
Q

Describe primary protein structure

A

The sequence of amino acids in a polypeptide chain

109
Q

State the bonds in the primary protein structure

A

Peptide bonds

110
Q

How is the sequence of amino acids in a polypeptide chain determined?

A

By the sequence of bases in the gene that codes for it

111
Q

Describe secondary protein structure

A

Alpha helices joined by hydrogen bonds

112
Q

Describe where hydrogen bonds form between alpha helices

A

Between NH+ (amine group) and CO- (carboxyl group) (NOT R GROUPS)

113
Q

Describe the tertiary structure of a protein

A

Alpha helices are folded into a 3-D shape

114
Q

State the bonds/interactions that can occur within a tertiary protein

A

Hydrogen bonds, disulphide bridges, ionic bonds, covalent bonds

115
Q

Explain how the 3D structure of a protein is determined

A

The tertiary structure depends on the sequence of amino acids because this determines the type and position of the bonds between R groups.

116
Q

Describe the quaternary structure of a protein

A

When two or more subunits (polypeptides) bond together.

117
Q

State the bonds/interactions that can occur within a quaternary protein

A

Hydrogen bonds, disulphide bridges, ionic bonds, covalent bonds

118
Q

Describe why the 3D shape of an enzyme is important to its function

A

The 3D shape of the active site must be complementary to the substrate

119
Q

Describe why the 3D shape of a hormone is important to its function

A

The 3D shape of the hormone must be complimentary to the receptor.

120
Q

Describe the reaction that breaks down polypeptides

A

One molecule of water is removed to break the peptide bond between amino acids

121
Q

Name the two main groups of proteins

A

Fibrous (structural) and globular (functional)

122
Q

Give three examples of structural proteins

A

Keratin, collagen, elastin

123
Q

Give three examples of functional proteins

A

Haemoglobin, insulin, any enzyme or hormone

124
Q

Why is it important for globular proteins to be soluble in water?

A

So they can dissolve in the blood and be transported through the body.

125
Q

Describe the structure of collagen

A

Three polypeptide chains, wound into a rope like shape. Crosslinks between chains.

126
Q

Describe the function of collagen

A

Provide strength and flexibility to connective tissue (e.g. tendons & ligaments)

127
Q

Name the food test for reducing sugars, and state a positive result

A

Benedict’s solution. A positive result - brick red precipitate will form

128
Q

Describe how to carry out the test for reducing sugars

A

Add Benedicts solution and heat.

129
Q

Describe how to carry out the test for non-reducing sugars

A

Test using Benedict’s solution, and you’ll get a negative result. Boil the sample with acid, and neutralise with alkali. Test again with Benedict’s solution, and a brick red precipitate will form (a positive result).

130
Q

Describe and explain the positive result for the test for non-reducing sugars

A

Non-reducing sugars are converted into reducing sugars, so Benedict’s solution turns brick red

131
Q

Name the food test for proteins, and a positive result

A

Biuret reagent. Positive result - purple

132
Q

Name the food test for lipids, and state a positive result

A

Emulsion test (ethanol). Positive result - a cloudy emulsion

133
Q

Describe how to carry out the emulsion test

A

Add ethanol, then distilled water and shake.

Biology (26 decks)

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