2.2 biological molecules Flashcards Preview

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1

nutrients are broken down by

digestion

2

anabolic reactions are where

products of digestion are digested into the blood stream and used to make larger molecules

3

metabolism is

the sum of all chemical reactions taking place in an organism

4

why is carbon so abundant in biomols

it can form 4 strong covalent bonds, it is very versatile

5

in condensation reactions, - join together to form a -

monomers join together to form a polymer

6

a water molecule is released in

condensation reactions

7

a covalent bond is made in

condensation reactions

8

a water molecule is used in

hydrolysis reactions

9

a covalent bond is broken in

hydrolysis reactions

10

hydrolysis reactions split - into -

polymers into monomers

11

carbohydrates monomer is

monosaccharides

12

carbohydrates polymer is

polysaccharides

13

proteins monomer is

amino acids

14

proteins polymer is

polypeptides

15

nucleic acids monomer is

nucleotides

16

nucleic acids polymer is

DNA and RNA

17

water is a - molecule

polar

18

bonds in water are

hydrogen bonds

19

the density of water is

997kg/m3

20

water is most dense at

4 degrees c

21

the density of water makes it a good...

habitat, as ice floats on its surface

22

what are adhesive properties

molecules are highly attracted to other molecules

23

does water have adhesive properties

yes

24

water's adhesive properties make it a good... because...

transport medium, they create a pull on the water column, which plants use to transport water from roots to leaves

25

water has a surface tension of - at room temperature

72mN/m

26

the high surface tension of water makes it a good - because...

habitat, insects can float on the surface and carry out actions there

27

water has a - latent heat of vaporisation

high

28

the high latent heat of vaporisation of water makes it a good- because...

means of temperature regulation because it means it can be used in humans for their sweat without it vaporising too easily, causing excessive sweating

29

water has a specific heat capacity of...

4200J/kg c

30

water has a - specific heat capacity

high

31

water's high specific heat capacity means it is useful in
1. because...
2. because ...

1. means of temperature regulation, heat can be stored in water and then used to regulate the temperature of nearby land at the coastline
2. transport medium, it can retain heat and then distribute it through warm blooded animals

32

water molecules have a - arrangement of - and - atoms

polar, hydrogen and oxygen

33

hydrogen is - charged, so attracts things which are -

positively, negative

34

oxygen is - charged, so attracts things which are -

negatively, positive

35

water being a polar molecule makes it a good - because...

solvent, it can strongly attract other molecules, disrupting the forces of attraction between molecules and dissolving them

36

water has a - latent heat of fusion

high

37

does water freeze easily?

no

38

water's high latent heat of fusion makes it a good - because...

habitat, it doesn't freeze too easily

39

water's appearance is...

clear and colourless

40

water's appearance makes it a good - because...

habitat, light can reach organisms living in the water

41

water is very - so can...

viscous, slide easily

42

waters viscosity makes it a good - because

means of transport because structures can easily move through it to transport materials

43

carbohydrates role in the body

energy in respiration

44

proteins role in the body

growth and repair, enzymes, antibodies, hormones

45

lipids role in the body

insulation, fatty cell membranes, electrical insulation

46

vitamins and minerals role in the body

coenzymes and activators, form parts of larger molecules

47

nucleic acids role in the body

carry the genetic code

48

water role in the body

keep cells turgid, provide a site for chemical reactions

49

what is a covalent bond

a strong bond made between 2 atoms formed by the sharing of electrons

50

what type of bonding is present within a water molecule?

covalent

51

what type of bonding is present between water molecules?

hydrogen

52

what 3 types of substance dissolve easily in water

1. soluble substances
2. polar molecules
3. hydrophilic materials

53

monosaccharides general formula

Cn (H2O)n

54

how many carbon atoms in a triose sugar

3

55

how many carbon atoms in a pentose sugar

5

56

how many carbon atoms in a hexose sugar

6

57

the monosaccharides found in DNA and RNA are - sugars

pentose

58

all monosaccharides are - sugars

reducing

59

monosaccharides can reduce - in - to-

blue cu2+ ions in Benedict's reagent to red cu+ ions

60

properties of monosaccharides are...

sweet, water soluble, form crystals

61

glucose molecules contain many bonds which can be - during - to -

broken down, respiration, release energy

62

energy released from glucose is used to

make ATP

63

break down of glucose in living organisms occurs in a series of

enzyme controlled steps

64

if the hydroxyl group is below, it is

alpha glucose

65

is the hydroxyl group is above, it is

beta glucose

66

which type of glucose can be used in respiration

alpha glucose

67

why can't animals use beta glucose?

because they have enzymes which can only break down the shape of alpha glucose

68

what do you use to test for reducing sugars

Benedict's reagent

69

if glucose is present, Benedict's reagent goes from

blue to red or blue- green- yellow- orange- red

70

monosaccharides join together in - reactions to form - then -

condensation, disaccharides, polysaccharides

71

when monosaccharides join together in condensation reactions, they form a - and - is produced

glycosidic bond, water

72

maltose and lactose are

reducing sugars

73

sucrose is a

non reducing sugar

74

examples of disaccharides are

maltose, lactose, sucrose

75

can sucrose reduce the Cu2+ in Benedict's reagent?

no

76

for sucrose to reduce the Cu2+ in Benedict's reagent, it must first be...

hydrolysed by acid

77

maltose is - with Benedict's reagent

positive

78

lactose is - with Benedict's reagent

positive

79

sucrose is initially - with Benedict's reagent

negative

80

sucrose is - with Benedict's reagent once it has been hydrolysed by acid

positive

81

glucose + glucose --->

maltose

82

glucose + fructose --->

sucrose

83

maltose has a - bond

alpha 1-4 glycosidic

84

sucrose has a - bond

alpha 1-2 glycosidic

85

what are polysaccharides?

polymers containing many monosaccharides

86

polysaccharides contain - bonds

glycosidic

87

polysaccharides are formed by - reactions

condensation

88

all polysaccharides are -, so make good...

insoluble, storage molecules and building materials

89

starch function

energy storage in plants

90

starch is a

heteropolysaccharide

91

starch is a mixture of the 2 polysaccharides

amylose and amylopectin

92

amylose contains - bonds

alpha 1-4 glycosidic

93

amylose is a chain of

alpha glucose monomers

94

amylose coils to form a…

Compact helical structure

95

In amylose - bonds are holding its shape

Hydrogen

96

In amylose, the - groups on the outside can form - bonds with water, so amylose is

OH, H, soluble

97

Amylopectin has faster reactions as…

it has more ends to be hydrolysed

98

Amylopectin is made from

Glucose monomers

99

Amylopectin is branched because

It contains both 1-4 and 1-6 glycosidic bonds

100

How do you test for starch?

Iodine

101

When starch is present, iodine goes from - to-

Brown - blue/ black

102

Glycogen function

Energy storage in animals

103

Glycogen is made from

Alpha glucose monomers

104

Glycogen is similar in structure to

Amylopectin

105

glycogen is a

polysaccharide

106

glycogen contains more - bonds than amylopectin

1-6 glycosidic

107

does glycogen leave the cell? why?

no, it is too large

108

is glycogen soluble

no

109

glycogen does not affect

osmotic potential

110

cellulose is found in

plant cell walls

111

cellulose is made from

beta glucose monomers

112

cellulose contains - bonds

hydrogen

113

the bonds in cellulose are WEAK or STRONG

strong

114

in cellulose, glucose monomers alternate their - by

orientation, 180 degrees

115

in cellulose, - is removed

H2O

116

cellulose is - because there are no - groups present to from - bonds with

insoluble, OH, hydrogen

117

cellulose have strong linear chains which form layered - which are crossed together by more - bonds to form -

microfibrils, hydrogen, macrofibres

118

the strong structure of cellulose is used to...

give the plant strength, structural support and rigidity

119

the basic monomer unit of proteins is

amino acids

120

- reactions link amino acids together into a - by forming a -- bond and releasing -

condensation, dipeptide, covalent peptide, water

121

the addition of another amino acid to a dipeptide creates a -

polypeptide

122

how many R groups are there

20

123

what is the carboxyl group in proteins

OH

124

in amino acids, the only thing that separates them is the -

R group

125

some R groups can be - or -

charged or hydrophilic/ hydrophobic

126

define amphoteric

something with both acidic and basic properties

127

which amino acid has sulfur in its R group?

cysteine

128

how do we test for proteins

with biuret reagent

129

plants can manufacture all of their amino acids using - from -

nitrogen from the soil

130

animals can only make some amino acids, so they need to get some from their -

diets

131

can animals store excess amino acids?

no

132

animals can't store excess amino acids because...

their amino groups make them toxic

133

what is deamination

when the amino group is removed from amino acids

134

amino acids are converted to - and excreted via the -

urea, kidney

135

peptide bonds are between - and -

carbon and nitrogen

136

biuret's reagent goes from - to - if protein is present

pale blue to purple

137

protein reduces the - ions in biurets to - ions

cu2+ to cu+

138

covalent peptide bonds are broken down by

protease enzymes

139

formation and breakage of peptide bonds in organisms is controlled by

enzymes

140

what digests protein in the stomach

peptin

141

proteases regulate the breakdown of - so that their effects are not permanent

protein hormones

142

what 2 groups make an amino acid amtopheric?

basic amino group and acidic carboxyl group

143

the amino group has - and -

hydrogen and nitrogen

144

insulin function

controls blood glucose levels

145

haemoglobin fuction

transferring oxygen from the lungs to the tissues

146

Catalase function

Neutralisation of hydrogen peroxide through decomposition

147

name three globular proteins

insulin, haemoglobin, catalase

148

insulin structure

A protein composed of two chains (an A and B chain) linked together by Sulphur atoms

149

haemoglobin structure

Haemoglobin is composed of four polypeptides – two alpha, two beta

150

catalase structure

It is a tetrameric enzyme, consisting of four, identical tetrahedrally arranged subunits of 60 kDa (way of expressing molecular mass).

151

how does catalase's structure help its function

The presence of of the iron II atoms in the prosthetic groups allow catalase to interact with hydrogen peroxide and speed up its breakdown.

152

how does insulin's structure help its function

allows it to be soluble, which means it can travel in the bloodstream

153

how does haemoglobin's structure help its function

the Fe2+ ions present in the structure can each combine reversibly with an oxygen molecule, allowing it to transport oxygen around the body.

154

insulin specific groups

Rapid-acting insulin.
Short-acting insulin.
Intermediate-acting Insulin.
Mixed insulin.
Long-acting insulin.

155

haemoglobin specific groups

Haemoglobin S
Haemoglobin C
Haemoglobin E
Haemoglobin D

156

catalase specific groups

Monofunctional
heme-containing catalases
Heme-containing catalase-peroxidases
Manganese-containing catalases

157

name the 3 fibrous proteins

keratin, collagen, elastin

158

collagen function

a connective tissue found in the skin, tendons, ligaments and the nervous system

159

keratin function

providing flexibility in hair and nails, found on the lining of tissues

160

elastin function

allows heart vessels and alveoli to stretch under high pressure and then return to their regular shape

161

collagen structure

- triple helix of 3 tightly wound chains
- proline, hydroxyproline and glycine

162

elastin structure

- cross-linked strands with hydrophobic regions

163

level of protein structure of globular proteins

quarternary

164

elastin level of protein structure

quarternary

165

keratin structure

four alpha helical segments cross-linked by 3 beta chains

166

collagen role of structure in function

the tightly wound chains of amino acid create strong, long and thin fibrils which can be used to provide elasticity to the skin and to protect softer tissues.

167

elastin role of structure in function

the hydrophobic areas associate, causing elastin molecules to group together. When stretched these strands move apart but remain attached at the crosslinks. After stretching, the elastin molecules reassociate, springing back together.

168

keratin role of structure in function

cysteine in keratin is used to form disulphide bonds- these are strong covalent bonds. This helps as it makes keratin strong.

169

the sequence of amino acids in a polypeptide is called the

primary structure

170

the 2 secondary structures are...

alpha helix and beta pleated sheet

171

the tertiary structure is...

the secondary structures coiled together

172

the bonds responsible for holding the tertiary structure can be

disulfide bonds, ionic bonds, hydrogen bonds and hyrophobic and hydrophillic interactions

173

a quarternary structure is where

a protein is made from more than one polypeptide

174

state some functions of lipids

energy, insulation in blubber, hormones as steroids, hibernation for energy and warmth, electrical insulation in the myelin sheath, membranes as phospholipids

175

lipids are all made from -, - and - atoms

C, H and O

176

lipids are soluble in - but insoluble in -

organic solvents, water

177

lipids are all called - because they are made from at least 2 different molecules

macromolecules

178

lipids make up -% of the organic matter in a cell

5%

179

triglycerides are made from a - reaction between 1 - molecule and 3 - molecules

condensation, glycerol, fatty acid

180

triglycerides are more/ less dense than water

less

181

are triglycerides polar?

no they are non-polar

182

because triglycerides are non polar, they are - and -

hydrophobic and insoluble

183

glycerol is a simple molecule made from - joined to -

3 carbon atoms, 3 hydroxyl groups

184

saturated acids have - double bonds

0

185

unsaturated acids have - double bonds

1 or more

186

fatty acids contain an acidic - group

carboxyl group

187

fatty acids carboxyl group

CO2H

188

fatty acids have a general formula of - where R is a -

R.COOH, hydrocarbon tail

189

most naturally occurring fatty acids have - to - carbon atoms

14 to 22

190

phospholipids are produced when

an OH group of the glycerol combines with a phosphoric acids

191

phospholipids have a - head with 2 - tails

phosphate, fatty acid hydrocarbon

192

in phospholipids the fatty acid chains are -

hydrophobic

193

in phospholipids the phosphate head is - and -

polar and hydrophilic

194

cholesterol is made of - - rings

4 carbon

195

cholesterol is found in all ...

biological membranes

196

cholesterol is - and -

small and hydrophobic

197

cholesterol is made in the

liver

198

which type of fatty acid can bend

unsaturated

199

which type of fatty acid melts at a higher temperature

saturated

200

which type of fatty acid is solid at room temperature

saturated

201

excess cholesterol clumps in bile to form

gall stones

202

what is familial hypercholesterolemia?

a genetic disorder where the signal to stop cholesterol production fails, causing heart attacks at very young ages

203

how do you test for lipids

emulsion test
1. mix sample with ethanol
2. add solution to water
3. shake

204

if lipids are present, the emulsion test will show

a white emulsion layer formed at the top

205

to make the emulsion test semi quantitative, we can...

measure the density of a well mixed sample in a colorimeter

206

what are bisensors

an analytical device for the quantitative measurement of a biological response

207

ca2+ role

bone structure, muscle contraction, amylase cofactor, synaptic transmission

208

is anion positive or negative

negative

209

is cation positive or negative

positive

210

na+ role

nerve transmission, in LOH/CD, counter current multiplier

211

k+ role

nerve transmission, guard cell opening

212

h+ role

H bonds, blood pH, ETC in respiration

213

NH+4 role

formed from deamination of amino acids

214

NO-3 role

N source for plants to build up amino acids

215

HCO-3 role

CO2 transport, plasma buffer

216

Cl- role

amylase cofactor

217

PO-3,4 role

in phospholipids, ATP and nucleic acids

218

OH- role

involved in bonds

219

TESTING FOR REDUCING SUGARS qualitative method

1. add 10cm3 of benedicts to sample
2. place in 100 degrees c water bath for 15 mins
3. goes from blue- brick red if sugars present

220

TESTING FOR NON-REDUCING SUGARS qualitative method

1. hydrolyse the sugar in acid
2. add 10cm3 of benedicts to sample
3. place in 100 degrees c water bath for 15 mins
4. goes from blue- brick red if sugars present

221

TESTING FOR REDUCING SUGARS quantitative method

1. create glucose dilution series of 1%, 0.5%, 0.25%, 0.13%, 0.06% and UNKNOWN in beakers
2. place 2cm3 in boiling tubes
3. add 10cm3 of benedicts
4. place in 100 degrees c water bath for 15 mins
5. place in centrifuge tubes and centrifuge for 2 mins each
6. take supernatant and pipette into cuvettes
7. calibrate colorimeter with water in cuvette, should read 100% (red, transmission)
8. put cuvettes into colorimeter and record readings
9. create calibration curve on graph paper and use to determine unknown glucose concentration.