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YEAR 12- biology a-level > biological molecules > Flashcards

biological molecules Flashcards

1
Q

what is a monomer

A

repeating units that join together to form polymers

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2
Q

what is a polymer

A

chains of many repeating units/ monomers

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3
Q

what is a condensation reaction

A

joining 2 monomers together by creating a chemical bond and removing water

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4
Q

what is a hydrolysis reaction

A

splitting up of polymers by breaking a glycosidic chemical bond by adding water

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5
Q

what type of bond is formed between 2 monosaccharides

A

glycosidic

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6
Q

what type of energy do simple sugars provide

A

short term energy release

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7
Q

what type of energy does complex carbohydrates provide

A

long term energy release

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8
Q

functions of carbohydrates

A

provide structure in plant cell walls
provide energy
regulates blood glucose

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9
Q

what are the monomers of carbohydrates

A

monosaccharides

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10
Q

what are the 3 main monosaccharides

A

glucose, fructose, galactose

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11
Q

what elements are carbohydrates made up of

A

carbon hydrogen oxygen

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12
Q

glucose + glucose —>

A

maltose

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13
Q

glucose + fructose —>

A

sucrose

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14
Q

glucose + galactose —>

A

lactose

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15
Q

what is the equation of a condensation reaction

A

monosaccharide + monosaccharide —> polysaccharide + water

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16
Q

what is the polymer starch made up of

A

repeating units of glucose

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17
Q

what is the equasion for a hydrolysis reaction

A

polysaccharide + water —> monosaccharide + monosaccharide

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18
Q

what do lipids do in living things

A

part of a cell membrane and provides insulation and energy

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19
Q

what does starch do

A

breaks down into glucose for energy

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20
Q

what are monosaccharides

A

single sugars

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21
Q

examples of monosaccharides

A

glucose fructose galactose

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22
Q

what polymer is made up of repeating units of alpha glucose

A

starch and glycogen

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23
Q

example of disaccharides

A

lactose sucrose maltose

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24
Q

what is the main function of starch

A

long term slow energy release

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25
Q

why is it helpful for starch to be insoluble

A

so osmosis can’t take place as cells would rupture without. cell membrane in high concentration

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26
Q

why is it helpful for starch to be coiled

A

more glucose molecules fits into a smaller space as its compact

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27
Q

what is an isomer

A

molecules with the same molecular formula but different structures

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28
Q

what are the 2 isomers of glucose

A

alpha and beta

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29
Q

what is the difference between alpha and beta glucose

A

the OH is below on the alpha glucose but on beta it is above

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30
Q

why can alpha glucose easily form polysaccharides

A

by condensation reactions and the OH is next to another one on the next monosaccharide

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31
Q

polymer of alpha glucose

A

starch and glycogen

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32
Q

polymer of beta glucose

A

cellulose

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33
Q

what is another name for starch

A

amylose

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34
Q

what are the features of starch

A

helical/ coiled structure
large
too big to escape cell membranes
compact
insoluble
many branches

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35
Q

what does glucose turn into in the liver

A

glycogen

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36
Q

what is glycogen

A

polymer of alpha glucose, stores energy in animals

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37
Q

features of glycogen

A

not coiled
has tons of branches for faster energy release
many ends
insoluble

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38
Q

similarities between starch and glycogen

A

starch and glycogen are both:
insoluble
branched
polysaccharides- alpha glucose
made up of carbon hydrogen and oxygen
long term energy stores

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39
Q

differences between starch and glycogen

A

glycogen isn’t coiled but starch is
glycogen has more branches than starch
glycogen is produced in animals but starch is in plants

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40
Q

why is it harder for beta glucose to form polymers than alpha glucose

A

one molecule needs to rotate upside down to have 2 OH’s next to eachother

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41
Q

why does each monomer of beta glucose need to be flipped

A

the H and OH are flipped so every other monomer must be flipped too, this gives strength for plant cell walls

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42
Q

what are the features of cellulose

A

unbranched chains called fibrils
chains don’t coil
strong intermolecular forces due to length (hydrogen bonds)
hard to seperate
strong and rigid

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43
Q

what are the structural similarities between starch and cellulose

A

both have glycosidic bonds
both are made up of carbon hydrogen and oxygen
both are poly saccharides of glucose

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44
Q

what are the structural differences between starch and cellulose

A

starch has branched ends whereas cellulose is unbranched chains
starch doesn’t have hydrogen bonds but cellulose does
starch is a polymer of alpha glucose, cellulose is a polymer of beta glucose
starch is helical, cellulose is straight

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45
Q

examples of polysaccharides

A

starch cellulose glycogen

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46
Q

examples of polysaccharides

A

starch cellulose glycogen

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47
Q

what are carbs proteins and nucleic acids examples of

A

polymers

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48
Q

what colour does benefits turn when testing for reducing sugar

A

blue > brick red

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49
Q

what colour does iodine turn when testing for starch

A

orange > blue/ black

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50
Q

what type of test is the starch test

A

qualitative (present or absent not a set number)

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51
Q

what is the function of a lipid

A

insulation
surround and protect organs
energy source
hormones

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52
Q

what is the structure of a triglyceride

A

1 glycerol molecule and 3 fatty acid molecules

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53
Q

what is the long hydrocarbon chain split into

A

acid group and R group

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54
Q

if lipids contain less oxygen than carbohydrates what does that lead to

A

less energy produced by lipids

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55
Q

what are the 2 groups of fatty acids

A

saturated
unsaturated

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56
Q

what does saturated mean

A

full of hydrogen

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57
Q

what does unsaturated mean

A

fewer hydrogen molecules and have atleast 1 double carbon bond

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58
Q

what is the structure of a lipid

A

contains fatty acids and glycerol

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59
Q

what type of bond forms in a triglyceride

A

ester bond

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60
Q

formation of spherical triglyceride droplets

A

hydrophobic fatty acids point inwards to avoid water and hydrophilic glycerols point outwards to attract water and form a circle

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61
Q

what are phospholipids made of

A

a phosphate ion and 2 fatty acid chains

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62
Q

what structure does a phospholipid make

A

a phosphate ion forms a strongly hydrophilic head and the tails are hydrophobic as they are uncharged

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63
Q

what form does phospholipids naturally form

A

a bilayer

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64
Q

what are the similarities between triglycerides and phospholipids

A

have fatty acids
made of c, h and o
form ester bonds
hydrophobic + philic
made by condensation

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65
Q

what are the differences between triglycerides and phospholipids

A

P has phosphorus, T doesnt
T have 3 fatty acids, P has 2
T form monolayer/ droplet, P forms a bilayer

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66
Q

what is the test for lipids

A

emulsion test

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67
Q

describe the emulsion test

A

add sample to test tube
add ethanol then equal amounts of water
(to dissolve fats then form a layer of lipids)
shake vigorously- white emulsion forms

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68
Q

name 3 organelles found in some bacterial cells

A

slime capsule
plasmid
flagellum

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69
Q

how many fatty acids are in a triglyceride

A

3

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70
Q

what organelle produces triglycerides

A

SER

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71
Q

structural difference between starch and cellulose

A

OH group is different
starch - A
cellulose- B

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72
Q

adaptations of cellulose for plant cells

A

straight fibrils with hydrogen bonds-
makes them strong and rigid for cell wall structure

73
Q

unsaturated

A

contain a double c=c bond

74
Q

why can’t triglycerides form a bilayer but phospholipids can

A

P- are equally hydrophilic and phobic and attract water
T- are mainly hydrophobic and form a droplet to keep water away as much as possible

75
Q

why are triglycerides mainly hydrophobic

A

triglyceride head is smaller than the tails so hydrophobic is dominant

76
Q

what elements are in all amino acids

A

nitrogen, oxygen, carbon, hydrogen

77
Q

give examples of a protein

A

enzymes
some hormones
antibodies

78
Q

what is the monomer of a protein

A

amino acid

79
Q

what 3 groups make up an amino acid

A

amino acid group
R/ variable group
carboxylic acid group

80
Q

what is the equation for a dipeptide formation

A

amino acid + amino acid = dipeptide + water

81
Q

how is a dipeptide and bond formed

A

by a condensation reaction between 2 amino acids, 1 H2O molecule is removed and a peptide bond is formed between the monomers

82
Q

2 ways in which all peptides are similar

A

have a carboxylic acid group
have an amino acid group

83
Q

1 difference between all dipeptides

A

different variable group

84
Q

what does the variable group of an amino acid determine

A

shape of a protein

by the amino acids it’s made of, and chemical bonds

85
Q

what is a protein made up of

A

more than 1 polypeptide

86
Q

what is determined by the shape of a protein

A

its function

87
Q

name the 4 factors that affect protein structure

A

primary
secondary
tertiary
quaternary

88
Q

describe what is the primary structure

A

determined by the sequence of amino acids that are joined by peptide bonds

89
Q

describe what is the secondary structure

A

H atoms of amino acids join to O atoms of other amino acids and form hydrogen bonds
causing the polypeptide to fold

creates alpha helix and beta sheet

90
Q

describe what the tertiary structure is

A

R groups of amino acids interact to form ionic bonds (due to + and - charges), hydrogen bonds and disulfide bridges,

these bonds cause the polypeptide to form 3D shapes

91
Q

describe what the quaternary structure is

A

polypeptides interact with other polypeptides and form proteins

92
Q

what is the definition of an enzyme

A

biological catalysts which speeds up the rate of reaction by lowering activation energy without being used up

93
Q

what are the limitations of enzymes

A

denature in high temperatures and ph, low temperatures cause the enzyme to work slower as they have less kinetic energy

94
Q

what is the main function of an enzyme

A

hydrolysis of larger molecules into smaller molecules

95
Q

how does the induced fit model of an enzyme work

A

enzymes active site and substrate shape isn’t complimentary at first

once binded= enzyme substrate complex
and active site changes shape to be complimentary to the substrate

forces substrate to bend and put a strain on the bonds

lowers activation energy= substrate is easier to break apart into products

96
Q

how does high/ low pH affect rate of reaction in enzymes

A

active site changes shape and denatures so it’s not complimentary
less enzyme substrate complexes are formed
slow rate of reaction

97
Q

how does high temperature affect rate of reaction in enzymes

A

active site denatures and is no longer complimentary
less enzyme substrate complexes are formed
slow rate of reaction

98
Q

how does low temperature affect rate of reaction in enzymes

A

active site doesn’t denature but slows down due to less kinetic energy
slow rate of reaction

99
Q

how does low temperature affect rate of reaction in enzymes

A

active site doesn’t denature but slows down due to less kinetic energy
slow rate of reaction

100
Q

how does enzyme concentration affect rate of reaction

A

substrate complex is limited
high concentration= more collisions
more enzyme substrate complexes
slower rate of reaction

101
Q

how is ATP synthesised (equasion)

A

ADP + Pi -> ATP + H2O

102
Q

how does substrate concentration affect rate of reaction

A

high= more collisions more enzyme substrate complexes
eventually rate slows down as enzyme concentration is a limiting factor

103
Q

how does competitive inhibitors affect the rate of reaction

A

inhibitor binds to the enzymes active site so the substrate can’t bind to the enzyme, less enzyme substrate complexes
slows rate of reaction as less substrates are broken down

104
Q

how does a non competitive inhibitor affect rate of reaction

A

bonds to an area away from the active site- (allosteric site) so the active site changes shape, less enzyme substrate complexes, slower rate of reaction

105
Q

how do you calculate rate of reaction

A

1/ mean(time taken)

106
Q

how do you calculate overall rate of reaction

A

total volume of product cm3/ total time taken s

107
Q

how does rate of reaction change over time

A

decreases and starts to slow down as there are less enzyme substrate complexes and collisions as the concentrations of enzymes and substrates decrease

108
Q

how do you calculate instantaneous rate of reaction

A

draw a tangent and calculate gradient
change in y/ change in x

109
Q

what is the test for proteins

A

buiret test
buiret reagent= sodium hydroxide+ copper sulfate
positive= purple
negative= blue

110
Q

how is ATP synthesised

A

created in a condensation reaction during respiration and photosynthesis using a ATP synthase enzyme, ADP + Pi

111
Q

how many ATP molecules are produced for each molecule of glucose breaking down

A

33

112
Q

what is the equation for breaking down ATP

A

ATP + H2O > ADP + Pi

113
Q

how is ATP broken down

A

ATP is hydrolysed - bonds break to release energy - when energy is required, by the enzyme ATP hydrolase

114
Q

what does adding a phosphate ion do to something

A

make it more likely to do chemical reactions to change is shape and make it change shape to be complimentary

115
Q

name and describe what is the process to produce energy

A

respiration- break down glucose using oxygen to produce energy, water and carbon dioxide forming an ATP molecule

116
Q

what is the structure of ATP

A

3 phosphate ions
ribose pentose sugar
nitrogenous base A

117
Q

give 2 ways the hydrolysis of ATP is used in cells

A

provide energy
make substances more reactive

118
Q

where do non competitive inhibitors bind to enzymes

A

allosteric site away from the active site

119
Q

what shapes do polypeptides fold into in the secondary structure

A

alpha helix
beta sheet

120
Q

where is dna found in a eukaryote and prokaryote

A

eukaryote- nucleus
prokaryote- plasmid and circular dna

121
Q

RNA has an extra what?

A

base ( U )

122
Q

what is dna made from

A

nucleotides

123
Q

wheee can dna be found in a virus

A

capsid

124
Q

what does dna do

A

code for a sequence of amino acids - polypeptides

125
Q

what is the structure of a nucleotide

A

1 phosphate ion
deoxyribose pentose sugar
nitrogenous base ATCG

126
Q

what are the differences between a nucleotide and ATP molecule

A

ATP has 3 phosphate ions, N has 1
ATP is always the adenine base, N can be any
ATP has ribose, N has deoxyribose

127
Q

what are the similarities between ATP and nucleotide molecules

A

same pentose sugar
have a nitrogenous base
contain a phosphate ion

128
Q

what is the condensation reaction for nucleotides

A

mononucleotide + mononucleotide > polynucleotide + water

129
Q

what is the name of the bond that forms between sugar and phosphate

A

phosphodiester bond ( phosphorous , 2 oxygen , carbon )

130
Q

what is complimentary base pairing

A

c + g
a + t

131
Q

what is one molecule of dna made up from

A

2 polynucleotide strands joined by hydrogen bonds between nitrogenous bases

132
Q

how is dna a polymer

A

made up of many repeating nucleotides

133
Q

describe semi conservative DNA replication

A
  1. parental dna gets copies
  2. strand splits, hydrogen bonds break by “dna helicase” enzyme
  3. free floating nucleotides line against complimentary bases, form hydrogen bonds
  4. nucleotides join to complimentary bases, for phosphodiester bonds by “dna polymerase”
  5. 2 dna molecules formed, identical to parental dna
134
Q

what does semi conservative mean

A

keeping half of the dna as a template

135
Q

what does dna helicase do

A

break down hydrogen bonds to seperate dna strands

136
Q

what does dna polymerase do

A

forms phosphodiester bonds during a condensation reaction, removing a water molecule and joining 2 complimentary base pairings

137
Q

where are free nucleotides found in the cell

A

nucleus

138
Q

what is the substrate and product of dna helicase

A

substrate- dna molecule
product- 2 seperate dna strands

139
Q

when does dna replication occur

A

interphase

140
Q

what elements are found in all nucleotides

A

h, c, o, n, p

141
Q

how long does it take for 1 piece of dna to replicate

A

1 hour

142
Q

what biological molecule is RNA

A

a polynucleotide

143
Q

what is the functions of RNA

A

transfer genetic information during protein synthesis
forms part of a ribosome

144
Q

structure of RNA

A

phosphate ion
ribose pentose sugar
nitrogenous base EXCEPT thymine
uracil

145
Q

name the 4 nitrogenous bases of RNA

A

adenine
cytosine
guanine
uracil

146
Q

how is DNA and RNA similar

A

both have:
phosphate ion
pentose sugar
nitrogenous bases
phosphodiester bonds

147
Q

how is DNA and RNA different

A

DNA has no oxygen, RNA has oxygen

DNA contains thymine, RNA doesn’t

DNA is double stranded, RNA is single stranded

DNA has paired bases, RNA doesn’t

DNA has no uracil, RNA has uracil

148
Q

what sugar is found in dna

A

deoxyribose

149
Q

what are the key properties of water

A

metabolite in chemical reactions
solvent
high specific heat capacity
high latent heat
cohesive

150
Q

why is water being a metabolite a key property?

A

it is used in chemical reactions such as condensation/ hydrolysis

151
Q

why is water being a solvent a key property?

A

it’s a solvent for polar molecules so reactions can occur, charged molecules dissolve

152
Q

why does water have a high specific heat capacity

A

takes a lot of energy to break hydrogen honds

153
Q

why is water having a high specific heat capacity a key property

A

allows temperature buffering so it stays at the same temeperature, enzymes don’t denature

154
Q

why does water having a high latent heat of evaporation a key property

A

allows cooling through evaporation

155
Q

why is cohesion of water important

A

produces surface tension for small organisms so they can float

156
Q

what are all of the properties of water a result of

A

hydrogen bonds

157
Q

what is the formula of a hydrogen ion

A

H+

158
Q

what is the formula of a iron ion

A

Fe 2+

159
Q

what is the formula of a sodium ion

A

Na+

160
Q

what is the formula of a phosphate ion

A

Po4 3-

161
Q

what is the formula of a calcium ion

A

Ca2+

162
Q

what is the role of hydrogen

A

controls Ph in fluids
used in respiration and photosynthesis

163
Q

what is the importance of hydrogen

A

affects enzyme controlled reactions by controlling ph

164
Q

what is the role of iron

A

bonds oxygen to red blood cells using haemoglobin

165
Q

what do the importance of iron

A

haemoglobin transports oxygen around the body and reach cells for aerobic respiration

166
Q

what is the importance of sodium

A

allows glucose to get to cells for respiration

167
Q

what is the role of sodium

A

involved in the process of glucose from food to blood

168
Q

what is the role of phosphate

A

forms sugar phosphate backbone in dna
phospholipids
atp
dna
rna

169
Q

what is the importance of phosphate in phospholipids

A

forms cell membrane

170
Q

what is the importance of phosphate in atp

A

energy release

171
Q

what is the importance of phosphate in dna

A

holds genetic information, codes for sequence of amino acids

172
Q

what is the role of calcium

A

stimulates muscle contraction

173
Q

what is the importance of calcium

A

movement by muscle contraction

174
Q

what is an ion

A

charged particle formed by losing or gaining an electron

175
Q

how is maltose produced

A

condensation reaction between 2 glucose molecules by removing 1 water molecule

176
Q

how is sucrose produced

A

condensation reaction between 1 glucose and 1 fructose molecule by removing 1 water molecule

177
Q

how is lactose produced

A

condensation reaction between 1 glucose and 1 galactose molecule by removing 1 water molecule

178
Q

what is the main property of all inorganic ions

A

don’t contain carbon atoms and found in cytoplasm

YEAR 12- biology a-level (6 decks)

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