Brainscape's Knowledge GenomeTM

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


See full index

A level Biology > Unit 1.4 - Biological reactions are regulated by enzymes > Flashcards

Unit 1.4 - Biological reactions are regulated by enzymes Flashcards

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

What is the shape of an enzyme and why?

A

3D spherical, globular shape
Polypeptide chain is folded back on itself

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

Which protein structure do enzymes have?

A

Tertiary

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

What causes the 3D spherical globular shape of an enzyme?

A

Polypeptide chain folding back on itself

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

What does the polypeptide chain folding back on itself cause for an enzyme?

A

Gives it its 3D spherical globular shape

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

What combines with an enzymes active site to form a product?

A

Substrate molecules

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

What do substrate molecules combine with on an enzyme to form a product?

A

Active site

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

What happens when a substrate combines with the active site of an enzyme?

A

A product forms

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

What can enzymes be described as?

A

Biological catalysts

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

What does the fact that enzymes are biological catalysts mean?

A

They speed up the rate of chemical reactions without undergoing permanent change

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

What number is high for enzymes?

A

High turnover number

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

High turnover number

A

Enzymes work efficiently to convert many substrate molecules of substrate into product per unit time

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

What does the fact that enzymes work efficiently to convert many substrate molecules of substrate into product per unit time mean?

A

They have a high turnover number

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

Why do enzyme reactions need to happen quickly?

A

To respond to changes in Environment

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

What do changes in Environment mean that enzymes have to?

A

Enzyme reactions need to happen quickly to respond to these changes

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

Where can enzymes react?

A

Inside or outside of the cell

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

Enzymes that react inside the cell

A

intracellular

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

Intercellular enzymes

A

Are synthesised and are active within the cell

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

Enzymes that act outside the cell

A

Extracellular

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

Extracellular enzymes

A

Synthesised within cells but are active outside

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

What’s similar and different between intercellular and extracellular enzymes?

A

Both - are synthesised within cells
Intercellular - are active inside the cell
Extracellular - are active outside the cell

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

Extracellular enzyme example

A

Digestive enzymes

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

What are digestive enzymes an example of?

A

Extracellular enzymes

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

Example of intercellular enzymes

A

Enzymes of respiration

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

What are enzymes of respiration examples of?

A

Intercellular enzymes

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

What is required in order for a reaction to occur?

A

Activation energy

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

What is activation energy required for?

A

A reaction to occur

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

What do enzymes enable reactions to do?

A

Occur at lower activation energies, so that they can occur at high rates even at relatively low temperatures

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

What do enzymes do to the activation energy of a reaction and what does this mean?

A

Lower the activation energy of a reaction
Chemical reactions can occur at high rates even at relatively low temperatures

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

Why is a reaction having a low activation energy good?

A

It can occur at high rates even at relatively low temperatures

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

What causes a chemical reaction to occur at high rates even at relatively low temperatures?

A

Enzymes lowering the activation energy of a reaction

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

Metabolism

A

All reactions that occur in the body

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

What’s the name for all reactions that occur in the body?

A

Metabolism

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

What do metabolism reactions occur in?

A

Sequences called metabolic pathways

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

Metabolic pathways

A

Metabolism reactions occur in these sequences

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

What are two types of metabolic reactions?

A

Anabolic
Catabolic

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

What are anabolic and catabolic reactions examples of?

A

Metabolic reactions

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

Anabolic reactions

A

Building up molecules

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

Type of reaction for building up molecules

A

Anabolic

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

Catabolic reactions

A

Molecules are broken down

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

Type of reaction when molecules are broken down

A

Catabolic

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

2 examples of anabolic reactions

A

Protein synthesis (amino acids in a chain form a polypeptide)
Condensation

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

What is protein synthesis an example of?

A

An anabolic reaction

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

What is condensation an example of?

A

An anabolic reaction

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

2 examples of catabolic reactions

A

Digestion
Hydrolysis

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

What is digestion an example of?

A

A catabolic reaction

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

What is hydrolysis an example of?

A

A catabolic reaction

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

What happens to the products of enzyme-controlled reactions?

A

Become a reactant in the next reaction

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

What is the reactant of an enzyme-controlled reaction?

A

A product of a different enzyme-controlled reaction

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

What type of reaction uses products to become reactants in the next reaction?

A

Enzyme-controlled reactions

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

Name three parts involved in a simple metabolic pathway

A

Substrate
Intermediate
Product

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

Example of a metabolic pathway

A

Glycolysis

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

What’s glycolysis an example of?

A

A metabolic pathway

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

Glycolysis

A

The start of cellular respiration - the way cells release energy

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

What’s glycolysis?

A

The start of cellular respiration - the way cells release energy
(Example of a metabolic pathway)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Which process is the start of cellular respiration - the way cells release energy?

A

Glycolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What do metabolic reactions occur as?

A

A series of small steps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What occurs in a series of small steps?

A

Metabolic reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is each step in a metabolic reaction?

A

A reaction catalysed by an enzyme due to the active site containing reactive molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Is each step of a metabolic reactions catalysed by the same enzyme?

A

No - a different enzyme (lots of different types in the cell)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What do different enzymes within a cell do?

A

Catalyse different steps within the metabolic reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What does each individual enzyme react with?

A

A particular substrate molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

How can we describe each individual enzyme?

A

Specific (to a particular substrate molecule)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What does the fact that enzymes react to a particular substrate molecule make it?

A

Specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Why are enzymes specific?

A

Each one reactions with a particular substrate molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Describe the relationship between the shape of the active site and a substrate molecule

A

Complementary (not the same!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What shape is the active site of an enzyme?

A

3D and globular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Is an active site’s shape the same as the substrate molecule?

A

No - its complementary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What’s the 3D globular shape of the active site of an enzyme maintained by?

A

Tertiary protein bonding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is maintained by tertiary bonding on an enzyme?

A

The 3D globular shape of the active site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What’s the first stage to how enzymes work?

A

Substrate and enzyme collide successfully

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What happens once a substrate has collided successfully with an enzyme?

A

Substrate fits into and binds to the active site by interactions with R groups/polar atoms of the amino acids that make up the active site to form an enzyme-substrate complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

How is an enzyme-substrate complex formed?

A

When the substrate fits into and binds to the active site of an enzyme by interactions with R groups/polar atoms of the amino acids that make up the active site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What forms when a substrate has bonded to the active site of an enzyme?

A

Enzyme-substrate complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What makes up the active site of an enzyme?

A

R groups/polar atoms of amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

How does a substrate bind to the active site of an enzyme?

A

Interactions with R groups/polar atoms of the amino acids that make up the active site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Which part of the enzyme do we call the enzyme-substrate complex?

A

The entire enzyme, with the substrate binded to it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is the ability of R groups and the substrate to form bonds affected by?

A

Temperature and pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What does temperature and pH affect the ability of?

A

R groups and the substrates ability to form bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

How are the bonds in the substrate broken in the active site of an enzyme?

A

They’re distorted, which puts strain on the bonds that are going to be broken and increase the chance that they’ll break

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What are distorted in order to put strain on the so that they break?

A

The bonds in a substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What does breaking the bonds of a substrate do?

A

Brings new atoms in the substrates closer together so that new bonds can form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

How do new bonds form within the substrate to form a product?

A

Breaking the bonds brings new atoms in the substrates closer together so that new bonds an form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What are the two theories of enzyme action?

A

Lock and key hypothesis
Induced fit model

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What does the original enzyme hypothesis suggest?

A

The lock and key hypothesis suggests there’s an exact fit between the substance and the active site of an enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Which enzyme hypothesis suggests there’s an exact fit between the substance and the active site of an enzyme?

A

Lock and key hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What’s the lock and key hypothesis supported by?

A

X-ray diffraction studies of enzyme molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What has X-ray diffraction studies of enzyme molecules supported?

A

The lock and key hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What type of metabolic reaction is an enzyme turning a substrate into a product? Why?

A

Anabolic - it involves enzyme building

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What are the two types of complex generated during an enzyme catalysing a substrate?

A
  1. Enzyme-substrate complex
  2. Enzyme-product complex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

Where does a substrate react and form a product?

A

Whilst still in the active site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

What holds the substrate molecule and why?

A

The active site of the enzyme to release activation energy and speed up the process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Anabolic enzymes

A

Build larger products from smaller substrate molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Which type of enzymes build larger products from smaller substrate molecules?

A

Anabolic enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

Catabolic enzymes

A

Break large substrate molecules into smaller products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

What type of enzymes break large substrate molecules into smaller products?

A

Catabolic enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

What happens with the induced fit model?

A

The enzyme molecule changes shape as the substrate molecules get close - the change in shape is ‘induced’ by the approaching substrate molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

What changes shape in the induced fit model and how?

A

The enzyme molecule, as it’s “induced” by the approaching substrate molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

What does the induced fit model rely on?

A

The fact that molecules are flexible because single covalent bonds are free to rotate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

Why are molecules flexible?

A

Single covalent bonds are free to rotate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

What does the induced fit model explain?

A

The ability of some enzymes that have a wide range of specificy, that can catalyse more than one substrate, due to the ability of the substrates to mould it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

What does the fact that some enzymes can catalyse more than one substrate give them?

A

A wide range of specificy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

Why do some enzymes ave a wide range of specificy?

A

They can catalyse more than one substrate due to the ability of the substrates to mould it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Two examples of enzymes with broad specificy

A

Lipase
Lysozyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

What are lipase and lysozyme examples of?

A

Enzymes with broad specificy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

Where’s lipase found?

A

saliva, stomach, pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

What’s found in the saliva, stomach and pancreas?

A

The enzyme lipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

What does the enzyme lipase do?

A

Breaks down fats in food so that they can be absorbed in the intestines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

Which enzyme breaks down fats in food so that they can be absorbed in the intestines?

A

Lipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

Where is the enzyme lysozyme found?

A

Tears
Saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

How does lysozyme work?

A

Cleaves the peptidoglycan component of bacterial cell walls
Binds to and breaks down the polysaccharide coating of a bacterial cell, leading to cell death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

Which enzyme binds to and breaks down the polysaccharide coating of a bacterial cell, leading to cell death?

A

Lysozyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

How is lysozyme an example of an enzyme with a wide range of specificy and therefore backs up the induced fit model?

A

The bacterial cells being destroyed have a wide range of cell walls and structures, so the induce fit model could explain this broad specificy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

Lysozymes break down bacteria, yet they have a wide range of cell walls and structures, so which model explains this?

A

The induced fit model, as this could explain the broad specificity of the lysozyme enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

What are the Environmental factors that effect the rate of enzyme catalysed reaction?

A

Temperature
pH
Substrate concentration
Enzyme concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

What do the environmental factors - temperature, pH, substrate concentration and enzyme concentration - effect?

A

the rate of enzyme catalysed reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

What happens between 0 degrees and optimum temperature in terms of enzyme catalysed reaction?

A

Increasing kinetic energy
Molecules move about me quickly
More collisions between them
Probability of successful collisions between the substrate and the active site of the enzyme to catalyse the reaction and form enzyme-substrate complexes/products increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

What do higher temperatures give enzymes and what does this cause?

A

Kinetic energy - molecules more about more quickly and there’s more collisions between them
The probability of successful collisions between substrate and the active site of the enzyme to catalyse the reaction and form an enzyme-substrate complex increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

What is formed following successful collision between an enzyme and a substrate?

A

An enzyme-substrate complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

What causes an enzyme-substrate complex to form?

A

Successful collisions between enzymes and substrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

What happens to the enzyme above optimum temperature?

A

High kinetic energy causes irreversible changes to the shape of the active site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

When are irreversible changes caused to the active site of an enzyme and what causes this?

A

When temperatures go above optimum for that enzyme
Kinetic energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

How is irreversible damage caused to the shape of the active site of an enzyme in temperatures above optimum?

A

High kinetic energy causes atoms to vibrate which breaks bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

At which point are irreversible changes caused to the shape of an enzyme’s active site?

A

Past optimum for that enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

How are the bonds in an enzyme’s active site broken?

A

When temperatures rise above optimum for that enzyme, and kinetic energy causes atoms to vibrate and this breaks the bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

Which bonds are broken on an enzyme’s active site when temperatures rise above optimum for that enzyme?

A

The bonds which maintain the tertiary structure of the enzyme
Hydrogen bonds, ionic bonds, disulphide bonds (covalent)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

When are the bonds which maintain the tertiary structure of an enzyme broken?

A

When temperatures rise above optimum for that enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

What happens when the bonds which maintain the tertiary structure of an enzyme are broken?

A

The substrate cannot fit into the active site (is no longer complementary) - the enzyme cannot continue to catalyse the reaction and has been denatured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

When has an enzyme been denatured?

A

When the temperatures have risen above optimum for that enzyme and the bonds which maintain the tertiary structure of the enzyme have been broken

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

What happens to a substrate molecule when approaching the active site of an enzyme that has been denatured?

A

Substrate molecule cannot fit into the active site
Enzyme cannot continue to catalyse the reaction and has been denatured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

Describe the active site of an enzyme when a substrate molecule can no longer fit into it due to it being denatured

A

No longer complementary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

What’s it important to always refer to when giving reasons for why an enzyme catalysed reaction has been effected in a certain way?

A

Kinetic energy
Collisions
Enzyme-substrate complexes/products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

What’s the order in which the bonds break in the tertiary structure of an enzyme? Why?

A

Hydrogen bonds (weakest)
Ionic bonds
Disulphide bonds (covalent - strongest)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

Which is the strongest of the bonds in the tertiary protein structure? Why?

A

Disulphide bonds, which are covalent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

Which of the bonds in the tertiary protein structure are weakest?

A

Hydrogen bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

Which enzymes tend to be more stable at high temperatures?

A

Enzymes with lots of disulphide bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

What do enzymes with lots of disulphide bonds tend to be more than other enzymes? Why?

A

More stable at higher temperatures - strongest of the bonds in tertiary protein structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

What happens in terms of enzyme catalysed reaction when the temperatures are relatively low?

A

Product is formed slowly due to low kinetic energy
Fewer vibrations of substrates and enzymes
Less frequent collisions between substrates and active sites to form enzyme-substrate complexes
Enzyme activity is low
Maximum product formation axes time to achieve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

Under which conditions does the maximum product formation take time to achieve and why?

A

Low temperatures
Low kinetic energy = fewer vibrations of substrates and enzymes
Less frequent collisions between substrates and active sites to enzyme-substrate complexes
Enzyme activity is low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

Under which conditions is enzyme activity low and why?

A

Lower temperatures - low kinetic energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

What does low kinetic energy levels due to low temperatures mean in terms of the formation of enzyme-substrate complexes? Why?

A

Less frequent collisions between substrates and active sites to form enzyme-substrate complexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

What is pepsin and what does it do?

A

An enzyme that catalyses the break down of proteins in the stomach, where pH is very acidic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

Which enzyme catalyses the break down of proteins in the stomach, where pH is very acidic?

A

Pepsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

Describe the pH of the stomach

A

Very acidic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

What is salivary amylose and what does it do?

A

A type of enzyme that digests starch to maltose in the mouth (works at a pH slightly higher than 7)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

At which pH does salivary amylose work?

A

Slightly higher than 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

Which enzyme works at a pH slightly higher than 7?

A

Salivary amylose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
147
Q

Which enzyme digests starch to maltose in the mouth?

A

Salivary amylose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
148
Q

What type of environment do enzymes always work in?

A

Solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
149
Q

Describe the pH range which enzymes have

A

Very narrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
150
Q

Do all enzymes have the same pH optima?

A

No - they all have very different pH ranges which they work in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
151
Q

What explains the fact that the digestive system has different regions?

A

All enzymes have very different pH ranges which they work in/pH optima

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
152
Q

How is the digestive system set out and why?

A

With different regions as all enzymes have different pH optima

153
Q

What do small changes in pH within the enzyme’s range do?

A

Affect the rate of reaction without affecting enzyme structure

154
Q

Which environmental change affects the rate of reaction for an enzyme but doesn’t affect its structure?

A

Small changes in pH within the enzymes range

155
Q

What do small changes outside an enzyme’s optimum range do?

A

Cause reversible changes in enzyme structure = inactivation

156
Q

Which environmental condition cause reversible changes in enzyme structure (inactivation)?

A

Small changes outside the enzyme’s pH range

157
Q

Reversible changes in enzyme structure caused by small changes outside the pH optimum range

A

Inactivation

158
Q

Inactivation

A

Reversible changes in enzyme stature due to small changes outside the pH optimum range

159
Q

What do extremes of pH do to an enzyme?

A

Can denature an enzyme

160
Q

What can denature an enzyme in terms of pH?

A

Extremes of pH

161
Q

How can we keep pH within a range?

A

Use chemicals which maintain a certain pH = Buffers

162
Q

What are buffers?

A

Chemicals which maintain a certain pH in order to keep it in suitable range

163
Q

How is an enzyme-substrate complex formed in terms of charges?

A

Charges on the amino acid side chains of the active site must attract charges on the substrate molecule

164
Q

Which charges must attract each other in order to form an enzyme-substrate complex?

A

Charges on the amino acid side chains of the active site and the charges on the substrate molecule

165
Q

What happens when the charges on the amino acid side chains of the active site attract the charges on the substrate molecule?

A

An enzyme-substrate complex forms

166
Q

What are the charges on an enzyme’s active site affected by?

A

Free hydrogen (H+) and hydroxyl (OH-) ions

167
Q

What do free hydrogen (H+) and hydroxyl (OH-) ions affect?

A

The charges of the enzyme’s active site

168
Q

Hydrogen and hydroxyl ions symbols

A

(H+) and (OH-)

169
Q

What may happen if the medium in which an enzyme and a substrate is in is too acidic?

A

Active site and substrate may end up with the same charge and repel one another
Slow down and eventually stop enzyme-substrate complexes from forming

170
Q

What would cause a substance to be too acidic in terms on ions?

A

Too many H+ ions

171
Q

What would too many H+ ions cause a substance to be?

A

Too acidic

172
Q

What would cause an active site and a substrate to have the same charge as one another?

A

Too many H+ ions (too acidic)

173
Q

What would stop being formed in a solution that’s too acidic and why?

A

Enzyme-substrate complexes
The active site and the substrate may end up with the same charge and would repel one another instead of attract one another

174
Q

In which situation would the active site of an enzyme and a substrate molecule repel one another?

A

When they’re ended up with the same charge, perhaps in a solution that’s too acidic

175
Q

What would an enzyme and a substrate do if they had the same charge, for example, from being in a solution that’s too acidic?

A

Repel one another, stopping enzyme-substrate complexes from being able to be formed

176
Q

Describe the graph that shows the affect of temperature on the rate of enzyme catalysed reaction?

A

Goes up quickly, slows down a little and then drops down to zero

177
Q

Vmax meaning

A

The maximum rate of reaction

178
Q

The maximum rate of reaction symbol

A

Vmax

179
Q

Describe the graph that demonstrates the affect of substrate concentration on enzyme catalysed reactions

A

Up steadily before flattening off

180
Q

What is the limiting factor at the start of a ‘substrate concentration’ vs ‘rate of reaction’ graph?

A

Substrate concentration

181
Q

What is the limiting factor at the end of a ‘substrate concentration’ vs ‘rate of reaction’ graph?

A

Enzyme concentration/number of active sites

182
Q

On which part of a ‘substrate concentration’ vs ‘rate of reaction’ graph is substrate concentration the limiting factor?

A

The start

183
Q

On which part of a ‘substrate concentration’ vs ‘rate of reaction’ graph is enzyme/active site concentration the limiting factor?

A

The end

184
Q

Something that limits the rate of reaction

A

Limiting factor

185
Q

Limiting factors

A

Something that limits the rate of reaction

186
Q

What happens to the rate of reaction in terms of the substrate concentration as long as the enzyme concentration remains constant?

A

The rate of reaction will increase as the substrate concentration increases

187
Q

What has to remain constant for the rate of reaction to increase as the substrate concentration increases?

A

Enzyme concnetration

188
Q

Why does the rate of reaction increase as the substrate concentration increases?

A

Plenty of free active sites - more likely for a collision between an active site and a substrate to form an enzyme-substrate complex

189
Q

What happens as the substrate concentration increases and why?

A

the rate of reaction increases (as long as the enzyme concentration remains constant)
Plenty of free active sites, making it more likely for a collision between an active site and a substrate to form an enzyme-substrate complex

190
Q

What happens to the rate of reaction after a certain point in terms of substrate concentration and why?

A

Reaction levels off once all of the active sites are simultaneously occupied - they’re saturated with substrate molecules without free active sites.
Rate of reaction stops increasing - the number of active sites has become a limiting factor.

191
Q

What’s the phrase for the active sites being simultaneously occupied at higher substrate concentrations?

A

Saturated with substrate molecules

192
Q

What are the active sites of enzymes at higher substrate concentrations and what’s the phrase for this?

A

Simultaneously occupied - saturated with substrate molecules

193
Q

What becomes a limiting factor after a certain point in terms of substrate concentration and why?

A

The number of active sites - saturated with substrate molecules

194
Q

How does the fact that there’s less available active sites at higher substrate concentrations affect the rate of reaction?

A

Stops increasing, as the probability of a substrate and enzyme colliding to form an enzyme-substrate complex decreases

195
Q

How does enzyme concentration affect the rate of reaction?

A

As long as the substrate concentration is in excess and temperature and pH are kept close to optimum, the rate of reaction is in direct proportion to the concentration of enzyme

196
Q

What would a graph showing ‘enzyme concentration’ vs ‘rate of reaction’ show and why?

A

A straight line through the axis, as they’re in direct proportion

197
Q

Which factor is in direct proportion to the rate of reaction of enzymes?

A

Enzyme concentration

198
Q

Which conditions have to occur for enzyme concentration to be directly proportional to the rate of reaction?

A

Temperature and pH close to optimum

199
Q

Why do higher enzyme concentrations increase the rate of reaction?

A

The more enzymes, the more free active sites available - higher probability of substrate molecules colliding with them to form enzyme-substrate complexes

200
Q

Initial rat of reaction

A

Instantaneous rate at the start of the reaction (t=0)
Factors such as substrate concentration haven’t had time to change

201
Q

What would we see on a ‘product concentration’ vs ‘time’ graph and why?

A

Steeper curve at the beginning which levels off
The initial rate of reaction is higher, with the substrate being turned into enzyme-substrate complexes
Less substrate available over time
Probability of successful collisions between enzymes and substrates decreases
Less product forms, due to a reduced rate of enzyme catalysed reaction

202
Q

What happens to product concentration in terms of enzyme reactions over time and why?

A

Decreases as less substrate is available over time, so the probability of successful collisions between enzymes and substrates decreases, so less product forms due to a reduced rate of enzyme catalysed reaction

203
Q

What happens to substrate concentration as a reaction progresses and why?

A

Falls - it’s converted into product

204
Q

What happens to the rate of product formation in an enzyme catalysed reaction over time and why?

A

Decreases as the substrate is used up

205
Q

What do inhibitors do?

A

Reduce or even stop the catalytic activity of enzymes in biochemical reactions

206
Q

What reduce or even stop the catalytic activity of enzymes in biochemical reactions?

A

Inhibitors

207
Q

What type of reactions do inhibitors stop catalytic activity within?

A

Biochemical

208
Q

What type of enzyme activity do inhibitors reduce or stop in biochemical reactions?

A

Catalytic activity of enzymes

209
Q

How do inhibitors inhibit enzyme reactions?

A

Block or distort (change the shape) of the active site

210
Q

What blocks or distorts the shape of an active site on an enzyme?

A

Inhibitors

211
Q

What are the two types of inhibitors?

A

Competitive inhibitors
Non-competitive inhibitors

212
Q

Competitive inhibitors

A

Occupy active sites and prevent substrate molecules from binding to active sites (“compete” with substrates for active sites)

213
Q

What occupy active sites and prevent substrate molecules from binding to enzymes?

A

Competitive inhibitors
(“Compete” with substrates for active sites)

214
Q

Non-competitive inhibitors

A

Attach to other parts (not the active site) of an enzyme molecule, perhaps distorting its shape

215
Q

What attach to other parts (not the active site) of an enzyme molecule, perhaps distorting its shape?

A

Non-competitive inhibitors

216
Q

Is the inhibitor within the active site of an enzyme permanent?

A

No, only a temporary situation

217
Q

Describe the situation in which a competitive inhibitor is within the active site of an enzyme?

A

Only temporary

218
Q

How can a competitive inhibitor enter the active site of an enzyme?

A

Has a complementary shape

219
Q

How does a competitive inhibitor reduce or stop the catalytic activity of an enzyme?

A

Has a complementary shape to the active site, allowing it to block it and prevent reactions from happening and enzyme-substrate complexes from forming

220
Q

What are prevented from forming as a result of competitive inhibitors?

A

Enzyme-substrate complexes

221
Q

What’s the similarity between a competitive inhibitor and a substrate molecule?

A

Structurally similar

222
Q

What’s the competitive inhibitor structurally similar to?

A

The substrate molecule that would fit in the enzyme’s active site

223
Q

What’s the probability of a substrate or an inhibitor entering the active site of an enzyme when their concentrations are equal?

A

50:50

224
Q

Which type of inhibitor has a 50:50 chance of entering the active site against the substrate?

A

Competitive inhibitors

225
Q

What has to be kept equal in order for the probability of a substrate and competitive inhibitor to enter an active site to be equal?

A

Their concentrations

226
Q

What would an increased concentration of substrate molecules mean for the probability of entering the active site with the presence of competitive inhibitors?

A

Increased probability of entering the active site

227
Q

What’s the name of the site the non-competitive inhibitor enters?

A

Allosteric site

228
Q

Allosteric site

A

The site on an enzyme a non-competitive inhibitor enters instead of the active site

229
Q

Where does a non-competitive inhibitor bind to an enzyme?

A

Not the active site, but the Allosteric site

230
Q

How do non-competitive inhibitors reduce or stop the catalytic activity of enzymes in biochemical reactions?

A

When they bind to the Allosteric site, it prevents the binding of the substrate by changing the shape of the active site

231
Q

What happen to the active site with non-competitive inhibitors and why?

A

Changes shape so the substrate in unable to bind with it as the inhibitor combines to the Allosteric site

232
Q

How can competitive inhibition be reversed?

A

Increasing the concentration of substrates

233
Q

Which type of inhibition is reversible?

A

Both types, but not always non-competitive inhibition

234
Q

Is non-competitive inhibition reversible?

A

Usually, not always

235
Q

What depends on non-competitive inhibition being reversible?

A

The concentration of inhibitor and substrate

236
Q

How could the affects of non-competitive inhibition be reversed?

A

Inhibitor detaches, allowing the enzyme to return to its normal shape for the reaction to continue

237
Q

If a non-competitive inhibitor detached itself from the enzyme, what would happen?

A

The enzyme would return to its normal shape and the reaction would be reversed and would be able to continue

238
Q

Example of non-competitive inhibitors causing damage

A

Compounds containing heavy metals such as lead, mercury, copper or silver are poisonous, as ions of these metals are non-competitive inhibitors for several enzymes - would affect enzymes in the cells, affecting metabolism in the process

239
Q

Name 4 compounds containing heavy metals

A

Lead
Mercury
Copper
Silver

240
Q

What do lead, mercury, copper and silver all have in common?

A

All compounds containing heavy metals, which are poisonous as their ions are non-competitive inhibitors for several enzymes

241
Q

Why are some heavy metal poisonous?

A

Their ions are non-competitive inhibitors for several enzymes, and therefore affect certain enzymes in the cell and metabolism too

242
Q

What type of inhibitors are the ions of some of the poisonous heavy metals?

A

Non-competitive inhibitors

243
Q

Give two examples of non-competitive inhibitors

A

-Heavy metals (e.g - lead, mercury, copper, silver)
-Cyanide

244
Q

What type of inhibitor is cyanide?

A

Respiratory non-competitive inhibitor

245
Q

Why is it bad that cyanide is a non-competitive respiratory inhibitor?

A

Stops someone from being able to produce ATP = stops metabolic activity in the cell

246
Q

Why would not being able to product ATP be bad?

A

Stops metabolic activity in the cell

247
Q

What would stop metabolic activity in a cell?

A

Not being able to produce ATP
(Perhaps from a respiratory non-competitive inhibitor like cyanide…)

248
Q

Describe the lines on a graph showing the effect of increasing substrate concentration on enzyme inhibition

A

Without inhibitor - steepest, reaches the maximum rate of reaction
With competitive inhibitor - less steep, but reaches the same maximum rate of reaction
With non-competitive inhibitor - least steep, doesn’t reach the maximum rate of reaction

249
Q

How come that the rate of reaction without an inhibitor and with a competitive inhibitor reaches the maximum rate as the substrate concentration increases for both?

A

All active sites are saturated

250
Q

Which two enzyme inhibition scenarios both reach the maximum rate of reaction as the substrate concentration increases and why?

A

Without inhibitor and with competitive inhibitor as all active sites are saturated

251
Q

What happens to the rate of reaction to a competitive inhibitor as the substrate concentration increases?

A

Increases, but is lower than without an inhibitor as they interfere

252
Q

Why does the non-competitive inhibitor have a lower rate of reaction and doesn’t reach the maximum rate of reaction as the substrate concentration increases compared to without an inhibitor and with a competitive inhibitor?

A

A certain proportion of enzyme molecules will be attached to a non-competitive inhibitor at a given time, decreasing the amount of available active sites for the substance - active sites are all saturated with substrate at a lower level

253
Q

Which inhibitor condition has the lowest rate of reaction as the substrate concentration increases and why?

A

With a non-competitive inhibitor
The active sites are all saturated with substance at a lower level

254
Q

Why does the rate of reaction not reach maximum with a non-competitive inhibitor as the substrate concentration increases?

A

As a certain proportion of enzyme molecules will be attached to a non-competitive inhibitor at a given time, decreasing the amount of available active sites for the substance

255
Q

Which inhibitor condition doesn’t reach the maximum rate of reaction as the substrate concentration increases and why?

A

With a non-competitive inhibitor
Active sites are all saturated with a substance at a lower level

256
Q

What does increasing the substrate concentration do to the affect of the competitive inhibitor and why?

A

Decreases its affect as the enzyme is more likely to collide with a substrate molecule and form a successful enzyme-substrate complex

257
Q

What condition decreases the effect of a competitive-inhibitor and why?

A

Increasing the substrate concentration as the enzyme is more likely to collide with a substrate molecule and form a successful enzyme-substrate complex

258
Q

How does increasing the substrate affect the rate of reaction in the case of the non-competitive inhibitor and why?

A

Doesn’t increase the rate of reaction as the substrate can no longer fit in the enzyme’s active site

259
Q

In which case will increasing the substrate concentration to increase the rat of reaction and why?

A

Non-competitive inhibitors
The substrate can no longer fit into the enzyme’s active site

260
Q

What does end-product inhibition occur in?

A

Some metabolic reactions

261
Q

What’s a risk that can occur in some metabolic pathways?

A

The end-product may build up in the cell and reach toxic concentrations if the reaction continues

262
Q

When could toxic concentrations occur in metabolic pathways?

A

When the end product builds up

263
Q

What can happen in some metabolic pathways if the end product builds up?

A

Toxic concentrations may be reached in the cell

264
Q

In which processes can end-product inhibition occur?

A

Some metabolic reactions

265
Q

End-product inhibition

A

The molecule formed at the end of a metabolic pathway acts as a competitive inhibitor to one of the enzymes in the pathway

266
Q

What’s it called when the molecule formed at the end of a metabolic pathway acts as a competitive inhibitor to one of the enzymes in the pathway?

A

End-product inhibition

267
Q

What type of inhibitor does the end product act as in the metabolic pathway during end-product inhibition?

A

A competitive inhibitor

268
Q

What does end-product inhibition do?

A

Slows down or inhibits the reactions in a metabolic pathway so that the end product doesn’t reach toxic concentrations in the cell

269
Q

How does end-product inhibition ensure that conditions in a cell don’t reach toxic concentrations?

A

Slows down or inhibits the reaction in a metabolic pathway so that the end product doesn’t build up too much

270
Q

What build up to cause toxic concentration within a cell?

A

The end-product of a metabolic pathway

271
Q

Which process stops toxic concentrations=t ions from Ewing reached within a cell?

A

End-product inhibition

272
Q

What must be ensured for end-product inhibition to work?

A

Part of the molecule must have a shape that’s complementary to the active site of the first enzyme to compete with the substrate for it

273
Q

The shape of which active site must the end-product molecule be complementary to to compete with a substrate for it?

A

The first enzyme in the metabolic pathway

274
Q

What’s significant about the first enzyme in a metabolic pathway?

A

The end-product molecule must have a shape that’s complementary to its active site in order to compete with a substrate molecule for it for end-product inhibition

275
Q

Which industries are enzymes used in?

A

Food, pharmaceutical and agrochemical

276
Q

What type of enzymes in particular are used on an industrial scale?

A

Immobilised

277
Q

What are immobilised enzymes often used on?

A

An industrial scale

278
Q

Immobilised enzymes

A

Enzymes that have been immobilised (fixed, bound or trapped) by being put in an inert/non-reactive support matrix

279
Q

Immobilise

A

Fix, bound or trap

280
Q

Word for fixing, bounding or trapping an enzyme

A

Immobilising

281
Q

How are enzymes immobilised?

A

They’re put in an inert/non-reactive support matrix

282
Q

Describe the support matrix that enzymes are put in in order to be immobilised

A

Inert/non-reactive
Solid or semi-solid

283
Q

4 examples of immobilisation of enzymes

A

Adsorption
Encapsulation
Entrapment
Covalent bonding

284
Q

What are Adsorption, encapsulation, entrapment and covalent bonding all examples of?

A

Emobilising enzymes

285
Q

What does asorption immobilisation use?

A

Charged polar glass to attract enzymes

286
Q

Which type of enzyme immobilisation uses charged polar glass?

A

Adsorption

287
Q

What does encapsulation for the emmobilisation of enzymes require?

A

A permeable membrane (e.g -nylon)

288
Q

Permeable membrane example

A

Nylon

289
Q

What is nylon an example of?

A

A permeable membrane

290
Q

Which type of enzyme emmobilisation requires a permeable membrane?

A

Encapsulation

291
Q

How does entrapment emmobilisation of enzymes work?

A

Use a gel (e.g - alginate) that form long, thin polymer units, where the substrate can easily enter but the enzymes are too big to exit the matrix of the gel

292
Q

How can substrates enter the matrix of an emmobilised enzyme?

A

Easily

293
Q

Can emmobilised enzymes exit their matrix? Why?

A

No - they’re too big

294
Q

Example of a gel used for the entrapment emmobilisation of enzymes

A

Alginate

295
Q

Alginate

A

Type of gel from seaweed used for the entrapment of emmobilised enzymes in a matrix

296
Q

Which type of enzyme emmobilisation uses a gel to form a matrix?

A

Entrapment

297
Q

What does the alginate gel form during the entrapment emmobilisation of enzymes?

A

Long, thin polymer units

298
Q

What are the long, thin polymer units of the matrix in the entrapment emmobilisation of enzymes?

A

Gel, such as alginate

299
Q

With covalent bonding emmobilisation of enzymes, what is required?

A

Support (e.g - cellulose)

300
Q

Which type of enzyme emmobilisation requires support?

A

Covalent bonding

301
Q

What’s an example of a support system for covalent bonding emmobilisation of enzymes?

A

Cellulose

302
Q

What does cellulose do in terms of emmobilised enzymes?

A

Supports covalent bonding emmobilised enzymes

303
Q

Name a type of immobilised enzyme which has an industrial use

A

Alginate beads

304
Q

What are the majority of the world intolerant to - what is this and why?

A

Lactose (milk sugar)
They don’t produce the enzyme that digests it

305
Q

Why are the majority of the world lactose intolerant?

A

They don’t produce the enzyme that digests it

306
Q

Milk sugar

A

Lactose

307
Q

How can lactose content in milk be decreased?

A

Using the enzyme lactase

308
Q

What can the enzyme lactase be used for?

A

Reducing lactose content in milk

309
Q

How does lactase reduce lactose?

A

Breaks the disaccharide into glucose and galactose

310
Q

How is the disaccharide lactose broken down into glucose and galactose?

A

Using the enzyme lactase

311
Q

Describe the process of reducing the lactose content in milk with alginate beads

A

Continuous

312
Q

Name a continuous process

A

Reducing the lactose content in milk with alginate beads

313
Q

What are the alginate beads with the immobilised enzymes contained within for reducing the lactose content in milk?

A

A wide glass tube

314
Q

What’s at the bottom of the wide glass tube that contains alginate beads for reducing the lactose content in milk?

A

A tap to regulate flow rate where the products come out

315
Q

What happens as milk flows through the column containing immobilised enzymes?

A

The substrate (lactose) diffuses into the alginate matrix and forms an enzyme-substrate complex with the lactase enzyme

316
Q

What’s our substrate in the case of using alginate beads to reduce the lactose content in milk?

A

Lactose

317
Q

What does lactose act as when reducing its content in milk?

A

A substrate

318
Q

What are the products from the formation of enzyme-substrate complexes within the alginate matrix to reduce lactose content in milk?

A

Monosaccharides glucose and galactose

319
Q

What do glucose and galactose (our products) do after being formed from the enzyme catalysed reaction within the alginate beads?

A

Diffuse out of the alginate beads and leave the column with the rest of the milk

320
Q

What diffuses out of the column when catalysing lactose to reduce its content in milk?

A

The monosaccharide products - glucose and galactose

321
Q

How can more successful enzyme-substrate complexes be formed within the wide glass tube when reducing the lactose content in milk? Why?

A

Reduce the flow rate of the milk, allowing more contact time between enzyme and substrate, allowing more successful enzyme-substrate complexes to be formed

322
Q

How can we make diffusion take place quicker within the wide glass tube for reducing lactose content in milk? Why?

A

Smaller beads, as this increases the surface area

323
Q

How can we make diffusion take place quicker when reducing lactose content in milk?

A

Use smaller beads, as it increases the surface area

324
Q

What would decreasing the flow rate of milk do when reducing lactose content in milk?

A

Allows more contact time between enzyme and substrate, allowing more successful enzyme-substrate complexes to form

325
Q

Name 8 advantaged of using immobilised enzymes

A
  1. Greater control over the process
  2. The enzyme does not contaminate the product
  3. The immobilised enzymes can be recovered and reused
  4. They can be used in a continuous process
  5. Only a small quantity of enzyme is needed
  6. The enzymes have greater stability and denature at higher temperatures compared to enzymes free in solution
  7. Immobilised enzymes can catalyse reactions over a wider range of pH
  8. More than 1 enzyme can be used -enzymes can be added or removed
326
Q

Example of immobilised enzymes not contaminating our product

A

Milk stays within the beads when reducing its lactose content

327
Q

What does adding immobilised enzymes do to the process?

A

Speeds it up

328
Q

What does removing immobilised enzymes do to a process?

A

Slows it down

329
Q

How do we speed up a process involving immobilised enzymes?

A

Add more immobilised enzymes

330
Q

How do we slow down a process involving immobilised enzymes?

A

Remove immobilised enzymes

331
Q

Two examples of uses of immobilised enzymes

A
  1. In alginate beads to reduce lactose content in milk
  2. Biosensors
332
Q

Biosensor

A

A device for measuring the concentration of a specific molecule in a mixture by converting a chemical reaction into an electrical signal

333
Q

A device for measuring the concentration of a specific molecule in a mixture by converting a chemical reaction into an electrical signal

A

Biosensor

334
Q

What do biosensors measure?

A

The concentration of a specific molecule

335
Q

How does a biosensor measure the concentration of a specific molecule?

A

Converts a chemical reaction into an electrical signal

336
Q

Why are immobilised enzymes used in biosensors?

A

Only react with their substrate (are specific)

337
Q

What would a higher concentration of a substrate in a mixture do to the strength of the reaction?

A

The higher the concentration, the stronger the reaction

338
Q

What happens within the biosensor as the concentration of a substrate increases?

A

Higher concentration of substrate - higher strength of electrical signal

339
Q

What happens if the concentration of substrate is high within the mixture in a biosensor?

A

Stronger reaction —> higher signal from the electrode —> converted to a higher electrical signal

340
Q

How would we get a higher electrical signal within a biosensor?

A

Higher signal from the electrode due to the stronger reaction from a higher concentration of the substrate in the mixture

341
Q

What does a higher electrical signal within a biosensor mean?

A

A higher concentration of the substrate

342
Q

What’s the first step within a biosensor?

A

Sample hits the immobilised enzymes to form enzyme-substrate complexes and form products

343
Q

What happens when products are formed within a biosensor?

A

Detector/electrode detects the presence of H202
high concentration = higher signal from electrode

344
Q

What happens within a biosensor when the electrode has generated a signal?

A

This is converted into an electrical signal

345
Q

What happens within a biosensor when an electrical signal has been generated by the electrode?

A

Electrical signal to an amplifier then a computer to be put on display

346
Q

What’s the unit used on a biosensor?

A

ppm

347
Q

Example of a sample that we could measure its substrate concentration in a biosensor

A

Glucose

348
Q

What’s the immobilised enzyme that would catalyse glucose?

A

Glucose oxidase

349
Q

Glucose oxidase

A

Immobilised enzyme that catalyses glucose

350
Q

What’s the product of reacting glucose oxidase with glucose?

A

Hydrogen peroxide

351
Q

What happens to amino groups of enzymes in acidic solutions?

A

Gain hydrogen atoms, giving it a positive charge

352
Q

When do the amino groups of an enzyme become positively charged?

A

When gaining hydrogen atoms in acidic solution

353
Q

What happens to the carboxyl group of an enzyme in alkaline solution?

A

Becomes negatively charged as it loses hydrogen ions

354
Q

When does the carboxyl group of an enzyme become negatively charged?

A

When in alkaline solution as it loses hydrogen ions

355
Q

Draw and label a graph showing a reaction occurring in terms of energy

A

(Check notes - under catalysis)

356
Q

Is the shape of the active site permanent following the substrate ‘inducing’ it its fit?

A

No - it’s unchanged by the reaction and can be re-used

357
Q

Can induced fit enzymes be reused?

A

Yes

358
Q

How do you calculate a rate when the dependant variable is the time?

A

1
——
Time

359
Q

How do you calculate a rate when the dependant variable is quantity?

A

Quantity
————
Time

360
Q

What’s the relationship between time and a rate?

A

The shorter the time, the higher the rate

361
Q

How do we work out optimum temperature or pH?

A

The shortest time or the highest rate

362
Q

What does the shortest time or the highest rate represent?

A

Optimum pH/temperature

363
Q

What does 1/time calculate?

A

A rate

364
Q

What does quantity/time calculate?

A

A rate

365
Q

Unit of rate

A

s-1

366
Q

Give an example of an important immobilised enzyme in a biosensor for diabetics

A

Glucose oxidase, to help detect glucose levels in the blood sample

367
Q

Which group of people can benefit from biosensors and why?

A

Diabetics, as using the immobilised enzyme glucose oxidase allows them to detect the amount of glucose in their blood

368
Q

what’s the difference between an inactivated and a denatured enzyme?

A

denatured - permanent change
inactivated - reversible

369
Q

how does inactivation and denaturing of an enzyme in terms of pH vary?

A

inactivation - occur either side of optimum pH, charges on active site repel the substrate
denatured - more at the extremes, ionic bonds broken in the active site

370
Q

Why do immobilised enzymes work at their maximum rates over a wider temperature than free enzymes?

A

More energy required to overcome weak bonds
Protection from higher temperatures
Shapes of active sites are maintained at higher temperatures

371
Q

Which react fastest at lower temperatures - immobilised enzymes or non-immobilised enzymes? Why?

A

Non-immobilised
More kinetic energy and free to move

372
Q

What are the key words to use in all enzyme questions?

A

Complementary
Specific
Enzyme-substrate complex

373
Q

What do we discuss in “difference in rate” questions with a graph?

A

Limiting factors at different points

374
Q

Why does an immobilised enzyme work at its maximum rate over a wider range of temperatures?

A

Stability from higher temperatures
More energy required to overcome weak bonds
Shape of active site is maintained at higher temperatures

375
Q

Why must a instance used to immobilise an enzyme be inert?

A

Must not affect the shape of the active site by reacting with the enzyme

376
Q

How does an enzyme actually catalyse a reaction?

A

When the substrate is in the active site, it puts strain o the bonds that are going to be broken in the substrate

377
Q

Why do the products of enzyme reactions leave?

A

They’re no longer complementary to the active site

378
Q

What do we always need to refer to when there’s an enzyme question based on temperature?

A

Kinetic energy

A level Biology (26 decks)

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