Enzymes Flashcards
(87 cards)
1
Q
These are biological polymers that catalyzes different chemical reactions, specifically in the human body.
A
Enzymes
2
Q
Enzymes are made of (a)______. However, some enzymes are made of (b)_______.
A
- (a) protein
- (b) lipid
3
Q
The ________ is composed of different types of cells, tissues, and other complex organs.
A
human body
4
Q
For efficient functioning of our body, it releases some ________ to accelerate biological processes like breathing or respiration, digestion of food, excretion or elimination of food products, and a few other metabolic activities in order for a human to sustain a healthy life.
A
chemicals
5
Q
________ are very important in all living entities, not only in human beings, which govern all the biological processes.
- It is a protein with catalytic properties due to its power of specific activation.
- They catalyze nearly all the chemical reactions taking place in the cells of the body.
A
Enzymes
6
Q
The name of an enzyme identifies the reacting substance which usually ends in what?
A
-ase
7
Q
Enzymes are a _____ chain of amino acids or protein which give rise to a 3-dimensional structure.
A
linear
8
Q
The sequence of __________ specifies the structure which in turn identifies the catalytic activity of the enzyme.
A
amino acids
9
Q
Upon heating, the enzyme structure _________, resulting in the loss of enzyme activity which typically is associated with the temperature of the environment.
A
denatures
10
Q
CHARACTERISTICS OF ENZYMES
- Have a _______ degree of specificity for their substrate.
A. Low
B. High
A
B. High
11
Q
CHARACTERISTICS OF ENZYMES
- They are __________. They can only alter the rate of reaction, not the position of the equilibrium.
A
regulatory
12
Q
CHARACTERISTICS OF ENZYMES
- They work under very ______ condition of temperature and pH.
A. Mild
B. Extreme
A
A. Mild
13
Q
CHARACTERISTICS OF ENZYMES
- They are _____ in the reactions they catalyze.
A. consumed
B. not consumed
Note: consumed means used up
A
B. not consumed
14
Q
ENZYME STRUCTURE
- Enzymes are (a)_______.
- They have a (b)________ shape.
- A complex (c)________ structure.
Example: Human pancreatic amylase
A
- (a) proteins
- (b) globular
- (c) 3-D
15
Q
HOW DO ENZYMES WORK?
- Each enzyme has a unique 3-D shape, including a surface groove called an ____________.
A
ACTIVE SITE
16
Q
HOW DO ENZYMES WORK?
- The enzyme works by binding a specific chemical reactant __________ to its active site, causing the substrate to become unstable and react.
A
SUBSTRATE
17
Q
HOW DO ENZYMES WORK?
- The resulting ________ is then released from the active site.
A
PRODUCT(s)
18
Q
HOW DO ENZYMES WORK?
- Enzymes catalyze reactions by weakening chemical bonds, which ______ activation energy.
A. LOWERS
B. HIGHER
A
A. LOWERS
19
Q
When an enzyme is interacting with its substrate, during the chemical reactions, together they are referred to as _____________.
ENZYME + SUBSTRATE
A
Enzyme - Substrate Complex (ESC)
20
Q
The basic mechanism of enzyme action is to _______ the chemical reactions which begins with the binding of the substrate with the active site of the enzymes.
A
catalyze
21
Q
The indented part of the enzyme is called what?
This is a specific area that combines the substrate.
- A region within an enzyme that fits the shape of substrate molecules.
- Products are released when the reaction is complete (they no longer fit well in the active site).
- Shape and chemical environment of the it permits chemical reactions to proceed more easily.
A
Active site
22
Q
THE SUBSTRATE
- The substrate of an enzyme are the ______ that are activated by the enzyme.
A
reactants
23
Q
THE SUBSTRATE
- Enzymes are ______ to their substrates.
A. specific
B. general
A
A. specific
24
Q
THE SUBSTRATE
- The specificity is determined by the ______
A. active site
B. enzyme
A
A. active site
25
__________ such as zinc, iron, copper, vitamins are sometimes need for proper enzymatic activity.
Common example of it is **Ribolyse**. Considered as an enzyme also.
**Non-protein substances**
NOTE:
Cofactors and Coenzyme are non-protein substances
26
It is more general term. Includes **both inorganic and organic** molecules.
Cofactors
27
It is a type of cofactor, but specifically **organic** molecules.
Coenzyme
28
Enzymes have varying degrees of ______ for substrates.
specificity
29
Enzymes may recognize and catalyze as:
* a (a)_______ substrate
* a (b)_______ of similar substrates
* a particular (c)_______
* (a) single
* (b) group
* (c) type of bond
30
Typically, enzyme activities are accelerated with ________ temperatures.
**increasing**
Note: When the temperature of the environment of enzymes increases, the activity accelerates.
31
As enzymes are functional in cells, the feasible condition for nearly all enzymes are temperatures that are _______.
**moderate**
Note: Although there are some enzymes that can stand in higher temperatures, but as much as possible, all enzyme temperature should be in moderate or normal.
32
At higher temperatures given at specific point, there is a drastic _______ in their activity.
For example:
* In denaturation of enzyme, in diluted solutions, purified enzymes denature quickly compared to enzymes in crude extracts.
**decrease**
Note: So denaturation of enzymes can also takes place when enzymes are incubated or placed in hot temperature for long durations. So more appropriate is to utilize a shorter time duration when it comes to incubation time to gauge the starting velocities of such enzyme reactions.
33
There are instances, like the active site of enzymes, there is a cleft or a pocket produced by the amino acids which take part in the catalysis and substrate binding. The amino acids forming an enzyme active site is not continuous along the sequence of the amino acid. So the active site amino acids are assembled to a cluster in the right conformation by the 3-dimensional folding of the primary amino acid sequence.
So the most frequent active site that amino acid residues out of the 20 amino acid forming the protein are the polar amino acids. What are these?
* **G**lutamine
* **C**ysteine
* **A**spartic Acid
* **S**erine
* **H**istidine
Others: **T**hreonine, **A**sparagine, **T**yrosine
*REMEMBER **GCASH-TAT***
34
The 3 essential amino acid residue that is actually involved in causing the formation of the products are what?
They also serve as proton acceptor or donor in Enzyme-substrate complex.
* Histidine
* Asparagine
* Glutamine
*Remember the acronym **HAG***
35
In this model of enzyme action,
* The active site has a rigid shape.
* Only substrates with the matching shape can fit.
* The substrate is a key that fits the lock of the active site.
**Lock-and-Key model**
Note: This is an older model, however, it does not work for all enzymes.
36
What are the 3 Types of Enzyme Specificity?
* Linkage
* Absolute
* Group
*Remember the acronym **LAG***
37
TYPES OF ENZYME SPECIFICITY
* Catalyze one type of reaction for a **specific type of bond**.
Example: **Chymotrypsin** catalyzes the hydrolysis of peptide bonds.
Linkage
38
TYPES OF ENZYME SPECIFICITY
* Catalyze one type of reaction for a **single substrate**.
Example: **Urease** catalyzes only the hydrolysis of urea.
Absolute
39
TYPES OF ENZYME SPECIFICITY
* Catalyze one type of reaction for **similar substrate**.
Example: **Hexokinase** adds a phosphate group to hexoses.
Group
40
In this model of enzyme action,
* The active site is flexible, not rigid.
* The shapes of the enzyme, active site, and substrate adjust to maximize the fit, which improves catalysis.
* There is a greater range of substrate specificity.
This model is more consistent with a wider range of enzymes.
Induced-fit model
41
It is a phenomenon by which the weight of chemical reaction is altered or enhanced without changing themselves.
Catalysis
42
During a chemical reaction, a catalyst remain ________. So the shape is permanent, both in terms of quantity and chemical properties.
A. changed
B. unchanged
B. unchanged
43
________ is one of those catalyst which is commonly known as your **biological catalyst**.
It is present in the living organisms such as humans, and this enhance their rate of reactions which take place within our body.
Enzyme
44
The conditions of the reaction have a great impact on the activity of the enzyme.
Enzymes are particular about the _______ condition provided for the reactions, like temperature, pH (whether acidic or alkaline), alteration in substrate or the alteration in changes in substrate concentration or and other things.
A. optimum
B. insufficient
A. optimum
45
IN ENZYME CONCENTRATION AND REACTION RATE
* The rate of reaction increases as enzyme concentration ________.
A. increases
B. decreases
A. increases (at constant substrate concentration)
46
IN ENZYME CONCENTRATION AND REACTION RATE
* At ________ enzyme concentrations, more enzymes are available to catalyze the reaction (more reactions at once).
A. lower
B. higher
B. higher
47
IN ENZYME CONCENTRATION AND REACTION RATE
* There is a ________ relationship between reaction rate and enzyme concentration (at constant substrate concentration).
A. linear
B. curve
A. linear
48
IN SUBSTRATE CONCENTRATION AND REACTION RATE
* ___________ activity occurs when the enzyme is saturated (when all enzymes are binding substrate).
A. Minimum
B. Maximum
B. Maximum
49
IN SUBSTRATE CONCENTRATION AND REACTION RATE
* The rate of reaction _______ as substrate concentration increases (at constant enzyme concentration).
A. increases
B. decreases
A. increases
50
IN SUBSTRATE CONCENTRATION AND REACTION RATE
* The relationship between reaction rate and substrate concentration is ________ (levels off) when the enzyme is saturated.
A. exponential and parallel
B. exponential and asymptotes
B. exponential and asymptotes
51
Think about what kind of cell or organism an _____ may work in.
enzyme
52
Temperatures for above the normal range causes the enzymes to _________.
Denature
53
Most enzymes work best near what pH?
Neutral pH (6 to 8)
54
For most enzymes, the optimum temperature is about?
30°C
55
One of the effects of temperature is when cold fish die at 30°C because their enzymes _______.
Denature
56
A few bacteria have enzymes that can _______ very high temperatures up to 100°C.
A. yield
B. withstand
**B. withstand**
Note: This is the reason why, sometimes, boiling can't effectively remove bacteria since they have enzymes that can help them live under high temperature.
57
This is a machine that operate at high temperature and pressure in order to kill microorganisms and spores. They are used to decontaminate certain biological waste and sterilize media, instruments and lab ware.
Autoclave machine
58
Most enzymes however are fully denatured at what temperature?
When enzymes are exposed to this level of temperature, they lose their natural structure and, as a result, their function.
**70°C**
Note: This denaturation is usually irreversible; after being exposed to high temperatures, most enzymes can't regain their original shape or function.
59
There are some foods that is better to be eaten _____ because high temperature decreases the enzymes of food which is needed in our body.
raw
60
What are the **4 Factors** that influence Enzyme Activity?
* Temperature
* pH
* Cofactors and Coenzymes
* Inhibitors
61
IN THE EFFECT OF PH
* Extreme pH levels will produce _______.
A. renaturation
B. denaturation
B. denaturation
62
IN THE EFFECT OF PH
* The structure of the enzyme is ______.
A. changed
B. unchanged
A. changed
63
IN THE EFFECT OF PH
* The active site is _____ and the substrate molecules will no longer fit in it.
A. properly shaped
B. distorted
B. distorted
64
IN THE EFFECT OF PH
* At pH values slightly different from the enzyme's optimum value, _____ changes in the charges of the enzyme and it's substrate molecules will occur.
A. small
B. big
A. small
65
When we eat and chew, we produce a salivary enzyme called what?
The purpose of this is to destroy some bacteria that are present in the food that we eat. Another is to soften the food so that it will be easier to swallow.
**Salivary amylase**
Note: Our GI Tract, specifically Stomach has a low pH (acidic) because of the presence of gastric acids in the stomach.
66
* They are chemicals that reduce the rate of enzymic reactions.
* They are usually specific and they work at low concentrations.
* They block the enzyme but they do not usually destroy it.
* It can be reversible and irreversible.
Inhibitors
67
What are the **2 Types of Enzyme Inhibitors**?
* Competitive Inhibitor
* Non-competitive Inhibitor
68
It is a type of Enzyme Inhibitor **where chemicals that resemble an enzyme's normal substrate and compete with it for the active site.**
It is reversible depending on concentration of inhibitor and substrate.
Competitive Inhibitor
69
It is a type of Enzyme Inhibitor that **do not enter active site, but bind to another part of the enzyme, causing the enzyme & active site to change shape.**
Usually reversible, depending on concentration of inhibitor & substrate.
Non-Competitive Inhibitor
70
It is an example of Competitive Inhibitor, it is a **drug that is used to help alcoholics quit drinking**.
It inhibits aldehyde oxidase, resulting in the accumulation of acetaldehyde during the metabolism of alcohol. Elevated acetaldehyde levels cause symptoms of nausea and vomiting.
Antabuse
71
It is an example of Non-competitive Inhibitor,
* Compounds containing **heavy metals** such as lead, mercury, copper or silver are ______. This is because ions of these metals are non-competitive inhibitors for several enzymes.
A. poisonous
B. non-poisonous
A. poisonous
72
Its purpose is to block an enzyme's activity that can kill a pathogen or correct a metabolic imbalance.
**Enzyme Inhibitors**
Note: Many medications are enzyme Inhibitors.
73
Enzymes are classified according to the type of reaction they catalyze.
What are the **6 Classification of Enzymes**?
* Oxidoreductases
* Transferases
* Hydrolases
* Isomerases
* Lyases
* Ligases
*Remember the acronym **OTHILL***
74
Classification of Enzymes
REACTIONS CATALYZED
* Oxidation - reduction
Oxidoreductases
75
Classification of Enzymes
REACTIONS CATALYZED
* Transfer groups of atoms
Transferases
76
Classification of Enzymes
REACTIONS CATALYZED
* Hydrolysis
Hydrolases
77
Classification of Enzymes
REACTIONS CATALYZED
* Rearrange atoms
Isomerases
78
Classification of Enzymes
REACTIONS CATALYZED
* Add atoms / remove atoms to / from a double bond
Lyases
79
Classification of Enzymes
REACTIONS CATALYZED
* Use ATP to combine molecules
Ligases
80
What enzyme is present in most fruits and vegetables?
It is the enzyme that facilitates the **browning of cut or bruised fruits and vegetables** by catalyzing this reaction.
Catecholase
81
Pineapple contains this enzyme.
It is a protease enzyme that **facilitates hydrolysis of protein**.
It is used as a meat tenderizer. Breaks down the collagen in meat.
Similarly, it can "tenderize" the delicate tissues in your mouth, which is why some people feel that prickly or tender sensation when eating fresh pineapple.
Bromelain
82
What are the **3 Typical Subclasses** of Oxidoreductases?
* **Oxidases** - Oxidation
* **Reductases** - Reduction
* **Dehydrogenases** - Remove 2H to from double bonds
83
What are the **2 Typical Subclasses** of Transferases?
* **Transaminases** - Transfer amino groups.
* **Kinases** - Transfer phosphate groups.
84
What are the **3 Typical Subclasses** of Hydrolases?
* **Peptides** - Hydrolyze peptide bonds.
* **Lipases** - Hydrolyze ester bonds in lipids.
* **Amylases** - Hydrolyze 1,4-glycosidic bonds in amylose.
85
What are the **3 Typical Subclasses** of Lyases?
* **Decarboxylases** - Remove Carbon Dioxide (CO2).
* **Dehydrases** - Remove Water (H2O).
* **Deaminases** - Remove Ammonia (NH3).
86
What are the **2 Typical Subclasses** of Isomerases?
* **Isomerases** - Convert cis and trans.
* **Epimerases** - Convert D and L isomers
87
What are the **2 Typical Subclasses** of Ligases?
* **Synthetases** - Combine molecules.
* **Carboxylase** - Add Carbon Dioxide (CO2)
