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Flashcards in Biological molecules Deck (106):
1

Bases in DNA

Cytosine
Guanine
Thymine
Adenine

2

Bases in RNA

Cytosine
Guanine
Uracil
Adenine

3

What are pyrimidines?

Smaller
1 carbon ring
C &; T/U

4

What are purines

Larger
2 carbon ring
G & A

5

Describe a nucleic acid

A large polymer

6

Describe a nucleotide

A monomer

7

Differences between DNA and RNA

DNA-
Long double strand (helix)
Deoxyribose sugar
A, C, G & T

RNA-
Single short strand
Ribose sugar
A, C, G & U

8

Similarities of DNA and RNA

Pentose sugars
Polymers
Made of nucleotides (monomers)

9

What are the complementary base pairings?

A & T/U = 2 hydrogen bonds
C & G = 3 hydrogen bonds

10

What bond is present in DNA?

Phosphodiester bond

11

What carbon do the phosphate groups attach?

Number 5

12

Covalent bond

Two atoms share a pair of electrons

13

What bond forms between glucose molecules

Glycosidic bond

14

What makes maltose

2 Glucose alpha
(1,4)

15

What makes lactose

Glucose beta and galactose
(1,4)

16

What makes sucrose

Glucose alpha and fructose
(1,5)

17

Another name for glucose molecules

Monosaccharide

18

Another name for maltose/sucrose etc. Molecules

Disaccharides

19

What makes cellulose

2x alpha beta
(1,4)

20

Properties of water

Temp constant- coolant (hydrogen bonds)
Transport medium
Minerals soluble in water
Transparent to light
Cohesion
Polar

21

What makes up amylose

Alpha glucose
(1,4)
(Helical)

22

What makes up amylopectin

Alpha glucose
(1,4) and (1,6)
(Branched)

23

What makes up glycogen

Alpha glucose
(1,4) and (1,6) every 25
(Branched and helical)

24

Another name for glycogen/amylose/amylopectin/cellulose

Polysaccharides

25

Bond in lipids?

Ester bond

26

What is a triglyceride molecule made up of?

A glycerol molecule
3 fatty acids

27

What is a phospholipid made up of

Phosphate Group
Glycerol
Fatty acids

28

What is the reaction forming lipids called

Esterification

29

Test for lipids

Emulsion test
Add ethanol- white emulsion forms

30

What are polysaccharides

Polymers made of monosaccharides

31

Joining together of lots of glucose molecules creates what?

A store of energy

32

What are characteristics of glycogen

1-4 and 1-6 carbon bonds
Chain formation with branches
Less tendency to coil
Easier to remove monomer units as has more ends

33

What are polysaccharides good energy stores?

Compact
Less soluble than monosaccharides

34

Why is it important that polysaccharides are less double in water

If they dissolved it would disrupt the cells water potential

35

Why are polysaccharides less soluble

Because of their size (larger)

36

Through what reaction are glycosidic bonds formed

Condensation

37

When bonded together what form does cellulose take

Straight chain

38

What prevents spiralling in cellulose

The alternate invention of the beta glucose molecules

39

What bonds prevent spiralling

Hydrogen bonds between rotated beta glucose molecules

40

What are micro fibrils made up of

Beta glucose molecules

41

What are macro fibrils made of

Microfibrils

42

Why is cellulose hard to digest

The glycosidic bonds are hard to break

43

Define lipids

A group of substances that are soluble in alcohol rather than water

44

Define macromolecule

Large biological molecule

45

Define phospholipid

A molecule consisting of glycerol, two fatty acids and a phosphate group

46

Characteristics of a lipid

Contain large amount of carbon and hydrogen and a small amount of oxygen
Insoluble in water
Soluble in alcohol

47

what do fatty acids contain

A carboxyl group at one end
Hydrocarbon tail

48

Why are fatty acids, acids?

The carboxyl group can ionise hydrogen therefore it is an acid and can produce free H+ ions

49

What does the carbon bond in an unsaturated fatty acid inhibit

Hydrogen atoms can't bond to the molecule

50

What do double bonds do

Provide a kink making the molecule more fluid

51

When does an ester bond appear

During the condensation reaction the water is given off creating a covalent bond between the glycerol and fatty acids

52

Five functions of lipids

Energy source
Energy store
Insulation
Buoyancy
Protection

53

What is different in the structure of a phospholipid to a triglyceride?

One of the fatty acids is replaced with a phosphate group

54

What part of a phospholipid is hydrophillic

Head

55

Why are fatty acids hydrophobic

They are non polar

56

What describes the properties of phospholipids in water

Amphiphatic

57

In a phospholipid bilayer where are the heads and tails

Tails in heads out

58

Cholesterol is what

A steroid alcohol or sterol
A type of lipid made without fattyacids or glycerol

59

Where is cholesterol found

Within the phospholipid bilayer

60

Define amino acids

Monomers of all proteins

61

Define peptide bond

A covalenf bond formed when two amino acids are joined by a condensation reaction

62

What are proteins

Large polymers consisting of long chains of amino acids

63

Three functions of proteins

Form structural components
Tendency to adopt specific shapes and make into enzymes
Act as carriers in membrane

64

Structure of an amino acid

Amino group at one end
R group and an added hydrogen in the middle
Carboxyl group on the end

65

What enzyme breaks down peptide bonds

Protease

66

When two amino acids bond what is it called

Dipeptide

67

When a long chain of amino acids join together what is it called

Polypeptide

68

What is used to test for starch

Iodine

69

What colour change happens if starch present

Blue/black

70

What is used to test for reducing sugars

Benedicts reagent

71

Colour change if reducing sugars present

Red

72

Define a reducing sugar

Sugar which gives electrons to other molecules

73

What test for non reducing sugars

Benedicts solution

74

Colour change for non reducing sugars (low to high)

Blue
Green
Yellow
Orange
Red

75

Test for proteins

Biurent reagent
Light blue to lilac

76

What are glycosidic bonds

Formed between monosaccharides by a hydrolysis reaction

77

Characteristics of monosaccharides

Soluble in water

78

Quaternary structure

Protein consists of more than one polypeptide chain

79

Secondary structure

Coiling or folding of an amino acids chain

80

Main forms of secondary structure

Helix and beta pleated sheet

81

Main forms of secondary structure

Helix and beta pleated sheet

82

Tertiary structure

3D shape of a protein molecule

83

If a protein adopts a supercoiled shape what is this called

Fibrous protein

84

If a protein adopts a spherical shape what is this called

Globular protein

85

Where are disulphide links

Between the R groups

86

What is a fibrous protein

Thin long structure
Insoluble in water

87

What is a globular protein

Molecules with spherical shape
Soluble in water

88

Prosthetic group

Non protein component

89

Describe a fibrous protein

Regular repetitive sequences of amino acids
Insoluble in water

90

What do fibrous proteins do

Form fibres which form a structural role

91

Characteristics of amylose

Coils into spiral shape
Binds on carbons 1 and 4
Hydroxyl group on carbon 2 for hydrogen bonds

92

Globular proteins tend to fold up into what shape

Sphere

93

Two enzymes that carry out dna replication

DNA helicase
DNA polymerase

94

What is a nucleotide made up of

Pentose monosaccharide
Phosphate Group
Base

95

How many hydrogen bonds does A & T form

2

96

How many hydrogen bonds can C & G/U make

3

97

What is Adenosine triphosphate made up of

Base
Pentose sugar (ribose)
3 phosphate groups

98

Releasing energy through ATP is what reaction

Hydrolysis

99

Storing energy through ATP is what reaction

Condensation

100

DNA vs RNA

differences- dna 2 long strands vs 1 short strand
Deoxyribose vs ribose
A,C, G & T vs A, C, G &U

101

Define transcription

Copying of the genetic code from DNA into mRNA

102

Define translation

Assembly of a polypeptide from the genetic code on the mRNA

103

Where is the codon and anti codon

Codon on ribosome
Anticodon on tRNA

104

What is the triplet code

Sequence of 3 based- the codon

105

Sense strand

Runs from 5’ to 3’

106

Antisense strand

Acts as template strand
Runs from 3’ to 5’