Enzymes Flashcards
1
Q
_________ is also called as Biological catalysts
A
Enzymes
2
Q
Enzymes increases the rate of reactions by a factor between ____ to ______ times
A
10^6, 10^12
3
Q
most enzymes are ________
A
Proteins
4
Q
It is nomenclature
A
Enzymes
5
Q
______ is not used up in reactions
A
Enzymes
6
Q
Enzymes is highly ______
A
Specific
7
Q
Enzymes is chemically recognize, it _____and ______
A
Bind, modify substrates
8
Q
Enzymes is high ______ weight compounds made up principally of chains of ______ linked together by _____ bonds
A
Molecular, amino acids, peptide
9
Q
Enzymes can be ______ and _____ with salts, solvents and other Reagents
A
Denatured, Precipitated
10
Q
Enzymes can be denatured and precipitated with _____, _____ and ____
A
Salt, solvents, other Reagents
11
Q
Enzymes require the presence of other compound- ______ before their _______ activity can be exerted
A
Cofactor, catalytic
12
Q
What are the different types of enzymes classes
A
Oxidoreductases
Transferases
Hydrolases
Lyases
Isomerases
Ligases
13
Q
Is a class of enzyme that transfer electrons (hydride ions or H atoms)
A
Oxidoreductases
14
Q
Is a class of enzyme that is involved in group transfer reactions
A
Transferases
15
Q
Is a class of enzyme that involved in hydrolysis of reactions (transfer of functional group to water)
A
Hydrolases
16
Q
In Hydrolases it involves the transfer of _____ groups to _____
A
Functional, water
17
Q
Is a class of enzyme which form double bonds by removal of groups
A
Lyases
18
Q
Is a class of enzyme that transfer of groups within the molecules to yield isomeric forms
A
Isomerases
19
Q
Is a class of enzyme that form C-C, C-S, C-O and C-N bonds by condensation reactions coupled to ATP cleavage.
A
Ligases
20
Q
In Ligases, enzyme that form C-C, C-S, C-O and C-N bonds by _____ reactions coupled to ____ cleavage.
A
Condensation, ATP
21
Q
In Ligases what bonds is formed due to condensation reaction
A
C-C
C-S
C-O
C-N
22
Q
Enzymes are highly ______ : they catalyze only ____ reaction, having a specific substrate. This specificity results from an enzymes specific three dimensional shape.
A
Specific, one
23
Q
The specificity of enzymes results to form what shape
A
Specific 3 dimensional shape
24
Q
What do you call to a part of enzyme that binds to the substrate
A
Active site
25
The three dimensional shape of the molecule to be reacted is called
Substrate
26
What is formed when the substrate and enzyme bind temporarily
Enzyme-substrate complex
27
The activation energy needed for the reaction to occur is ____
Reduced
28
After the reaction is _____ the substrate has formed a new ______ and enzyme is _____ to be _____
Complete, product, released, reused
29
What are the two main reasons why an enzyme is regulated
•it is a waste of energy if the cell continues sleep produce a large amount of enzyme even when the amount of substrate is very low
•if the amount of product from the enzyme catalyzed reaction is already more than what the cell needs
30
The enzyme must be turned ___ to be regulated
Off
31
What are the two enzyme action
Lock and key model
Induced fit model
32
It is a type of enzyme action that the substrate molecule has a specific 3 dimensional shape that allows it to fit of an enzymes active site.
Lock and key model
33
A type of enzyme action that interaction between the enzyme and substrate induces or changes the shape of the molecule to produce a suitable fit
Induced fit model
34
In induced fit model enzymes lower the free _____ of the transition state by stabilizing the ______
Energy, transition state
35
It is a non protein organic substance which dialyzable and thermostable and loosely attached to the protein part
Coenzymes
36
An organic substance which is dialyzable and thermostable which is firmly attached to the protein or apoenzyme portion
Prosthetic group
37
This include K+, Fe2+, Fe3+, Cu2+, Co2+, Zn2+, Mn2+, Mg2+, Ca2+ and Mo3+
Metal ion activator
38
An inactive enzyme is usually termed as _______ or ______
Zymogen, proenzymes
39
What are the activity that affect enzyme
Temperature
pH
Enzyme concentration
Substrate concentration
Covalent modification or phosphorylation or methylation
Inhibition
Allosteric effects
40
It is an inactive form
Proenzymes or zymogens
41
In order to activate this enzyme a small part of their polypeptide chain must be removed
Proenzyme (zymogens)
42
It is produced rather in its active form to avoid random reactions in body
Proenzyme or zymogens
43
In order to activate the proenzyme a ______ part of their _______ chain must be ________
Small, polypeptide, removed
44
Proenzyme are produced rather in its ______form to avoid random reactions in the body
Active
45
What are the examples of proenzyme or zymogens
Trypsinogen
Pepsinogen
Procaspase
Prolipase
46
This regulation happens when substance binds to a certain part of the enzyme (but not on its active site) and changes the shape of its active site
Allosterism
47
What do you call the enzyme that regulated in allosterism
Allosteric enzymes
48
The substance that attaches to the allosteric enzyme is called a _____ and the site to which it binds is called the _____
Regulator, regulatory site
49
A regulator that may inhibit the enzyme action
Negative modulation
50
Regulator may stimulate the enzyme action
Positive modulation
51
The attachment of the regulator to the enzyme is ______ and ______
Noncovalent, reversible
52
What are the two kinetic states in allosteric enzyme
R form (relaxed form)
T form (taut form)
53
A type of kinetic states that more active form of the enzyme
R form
54
The kinetic state that is less active form of the enzyme
T form
55
A ______ group is usually added to the apoenzyme changing the primary structure of the enzyme
Chemical
56
Addition or removal of the chemical group may cause the ______ or ____ of an enzyme
Activation, inhibition
57
Typical example of protein modification or covalent modification
Phosphorylation
Dephosphorylation
58
Is the process of adding phosphate group
Phosphorylation
59
An enzyme that catalyzes the breakdown of glycogen to glucose and is activated by addition of phosphate group
Glycogen phosphorylase
60
The enzyme involved in glycogen synthesise is deactivated by the presence of phosphate groups
Glycogen synthase
61
Is the removal of phosphate group
Dephosphorylation
62
This type of modulation takes place when the same enzyme catalyzing the same substrate appear in different tissue but in different form
Isoenzyme
63
What structure is formed when the same enzyme appears in different location with a different combination of subunits
Quaternary Structure
64
_______ Allow very specific metabolic reactions to meet the particular needs of a given tissue or developmental stage
Isoenzyme
65
What is the example of isoenzyme
Lactate dehydrogenase (LDH)
66
What are the two isoenzyme in LDH
H4
M4
67
The _____ isoenzyme is found in the heart
H4
68
An isoenzyme that can be found in skeletal muscle
M4
69
H4 isoenzymes functions in ______ condition
Aerobic
70
M4 isoenzyme function in ______ condition
Anaerobic
71
What are the different types of enzyme inhibitors
Reversible competitive inhibitor
Reversible non competitive inhibitor
Irreversible inhibitor
Uncompetitive inhibitor
72
A molecule that has same shape and charge distribution as the enzyme substrates
Reversible competitive inhibitor
73
It competes for occupancy at the binding site
Reversible competitive inhibitor
74
When the inhibitor is attached to the enzyme no reaction occurs this results to the ______ in enzyme activity
Decrease
75
When the complex breaks, the inhibitor _____ the active site. The enzyme is then _____ and ready to use
Leaves, free
76
What competes for the active site
Substrate and inhibitor
77
Increasing the substrate concentration will ______ the inhibitory effect
Decrease
78
A molecule that binds the enzyme other than the active site
Reversible non competitive inhibitor
79
Prevents the enzyme from performing its catalytic action
Reversible non competitive inhibitor
80
Non-competitive inhibitor changes the ______ of the enzyme but not the ______
Confirmation, active site
81
A molecule that forms strong covalent bond with the active site
Irreversible inhibitor
82
Binds to the enzyme substrate complex but not to a free enzyme complex
Uncompetitive inhibitor
83
They are generally activated by the substrate of the pathway and inhibited by the product of the pathway does allly turning the pathway on when it is needed
Allosteric regulation
84
Allosteric regulation is also known as
Feedback inhibition
85
Reversibly bind and dissociates from enzyme activity of enzyme recovered on removal of inhibitor usually non covalent in nature
Reversible inhibition
86
The characteristic of an enzyme that is acts on the one and only one substance
Absolute specificity
87
The characteristic of an enzyme that is acts on several structurally related substances
Relative specificity
88
The characteristic of an enzyme that is able to distinguish between stereoisomers
Stereochemical specificity
89
The substance that undergoes a chemical change catalyzed by an enzyme
Substrate
90
A non protein molecule or ion required by an enzyme for catalytic activity
Cofactor
91
An organic molecule required by enzyme for catalytic activity
Coenzyme
92
A catalytically inactive protein formed by removal of cofactor from an active enzyme
Apoenzyme
93
The location of an enzyme where a substrate is bound and catalysus occurs
Active site
94
The rate at which an enzyme catalyzes a reaction
Enzyme activity
95
The number of molecules of substrate acted on by one molecule of enzyme per minute
Turnover number
96
A quantity of enzyme that catalyzes the conversion of 1 umol of substrate per minute under specified condition
Enzyme international unit (IU)
97
The temperature at which enzyme activity is highest
Optimum temperature
98
The ph at which enzyme activity is highest
Optimum pH
99
A substance that decreases the activity of an enzyme
Enzyme inhibitor
100
A substance that binds to an enzyme at allocation other than the active site and alters the catalytic activity
Modulator
101
Allosteric enzyme has _____ structure whose activity is changed by the binding of ______
Quaternary, modulator
102
A substance that binds to an allosteric enzyme and increases its activity
Activator
103
A process in which the end product of a sequence of enzyme catalyzed reaction inhibits an earlier stop in the process
Feedback inhibition
104
The synthesis of an enzyme in response to a cellular need
Enzyme induction
105
pH optimum of pepsin
1-2 gastric
106
pH optimum of trypsin
8-9 intestinal
