1
Q
What type of organic compound contains the functional group –NH2?
A
Primary Amine
Amines are derivatives of ammonia where hydrogen atoms are replaced by alkyl or aryl groups.
2
Q
What type of amine is formed when ammonia reacts with a halogenoalkane?
A
Primary amine
The halogen atom is replaced by an –NH2 group.
3
Q
Fill in the blank:
Reaction of a halogenoalkane with ammonia is an example of _______ substitution.
A
nucleophilic
Ammonia acts as a nucleophile donating a lone pair.
4
Q
True or False:
Nitriles can be reduced to form primary amines.
A
True
Reduction adds hydrogen across the C≡N bond.
5
Q
What functional group must be reduced to convert a nitrile into a primary amine?
A
Nitrile group
The –C≡N group is reduced to –CH2NH2.
6
Q
Fill in the blank:
The reduction of nitriles to amines requires the addition of _______.
A
hydrogen
The triple bond is reduced to a single bond.
7
Q
True or False:
Aromatic amines can be prepared by reducing nitro compounds.
A
True
The nitro group (–NO2) is converted to an amine group (–NH2).
8
Q
What type of compounds are aromatic amines commonly used to manufacture?
A
Dyes
Many synthetic dyes are produced from aromatic amines.
9
Q
Fill in the blank:
The nitro group in aromatic compounds is represented as _______.
A
–NO2
Reduction converts it to –NH2.
10
Q
What reagent is commonly used to reduce nitro compounds to aromatic amines in the laboratory?
A
Tin and hydrochloric acid
The amine is then released by adding alkali.
11
Q
True or False:
Ammonia acts as a nucleophile when reacting with halogenoalkanes.
A
True
It donates a lone pair of electrons to the carbon atom.
12
Q
Why are aromatic amines important in industrial chemistry?
A
Dye manufacture
They are key intermediates in producing coloured compounds.
13
Q
What type of chemical behaviour do amines exhibit in aqueous solution?
A
Weak bases
Amines accept protons using the lone pair on the nitrogen atom.
14
Q
What particle allows amines to act as bases?
A
Lone pair on nitrogen
The lone pair can accept a proton (H+).
15
Q
Fill in the blank:
Amines act as bases because the nitrogen atom has a _______ pair of electrons.
A
lone
This pair can bond with H+ to form an ammonium ion.
16
Q
True or False:
Amines react with acids to form ammonium salts.
A
True
The amine accepts a proton from the acid.
17
Q
Which compound is generally the weakest base: ammonia, primary aliphatic amine, or primary aromatic amine?
A
Primary aromatic amine
Delocalisation of the lone pair reduces its availability.
18
Q
True or False:
Primary aliphatic amines are stronger bases than ammonia.
A
True
Alkyl groups donate electron density to nitrogen.
19
Q
Fill in the blank:
Alkyl groups increase the basic strength of amines by _______ electron density to nitrogen.
A
donating
This makes the lone pair more available to accept a proton.
20
Q
Why are aromatic amines weaker bases than aliphatic amines?
A
Lone pair delocalisation
The lone pair interacts with the benzene ring π system.
21
Q
True or False:
In aromatic amines, the nitrogen lone pair is partially delocalised into the benzene ring.
A
True
This reduces its ability to bond with H+.
22
Q
Fill in the blank:
When an amine accepts a proton, it forms an _______ ion.
A
ammonium
The nitrogen atom gains a positive charge.
23
Q
What factor mainly determines the basic strength of amines?
A
Availability of lone pair
The more available the lone pair, the stronger the base.
24
Q
Why do primary aliphatic amines act as stronger bases than aromatic amines?
A
Electron-donating alkyl groups
Alkyl groups increase electron density on nitrogen.
25
Why are **amines** able to act as **nucleophiles in organic reactions**?
Lone pair on nitrogen
## Footnote
The nitrogen atom can donate its lone pair to an electron-deficient carbon.
26
What type of **reaction** occurs when **ammonia reacts with a halogenoalkane**?
Nucleophilic substitution
## Footnote
The nucleophile replaces the halogen atom in the molecule.
27
# Fill in the blank:
In **nucleophilic substitution with halogenoalkanes**, ammonia acts as a _\_\_\_\_\_\_.
nucleophile
## Footnote
It donates a pair of electrons to the carbon atom.
28
# True or False:
**Ammonia reacting with a halogenoalkane** initially forms a **primary amine**.
True
## Footnote
The halogen is replaced by an –NH2 group.
29
What **product** forms when a **primary amine reacts further with a halogenoalkane**?
Secondary amine
## Footnote
The nitrogen becomes bonded to two alkyl groups.
30
# True or False:
Reaction of **amines with halogenoalkanes** can lead to **quaternary ammonium salts**.
True
## Footnote
Repeated substitution replaces all hydrogen atoms on nitrogen.
31
# Fill in the blank:
A **nitrogen atom bonded to four alkyl groups** forms a _\_\_\_\_\_\_ ammonium ion.
quaternary
## Footnote
These ions carry a permanent positive charge.
32
What **industrial application** commonly uses **quaternary ammonium salts**?
Cationic surfactants
## Footnote
They are used in detergents, disinfectants and fabric softeners.
33
# True or False:
**Ammonia** can react with **acyl chlorides to form amides**.
True
## Footnote
The chlorine atom is replaced by an –NH2 group.
34
# Fill in the blank:
The **reaction of ammonia with an acyl chloride** produces an _\_\_\_\_\_\_.
amide
## Footnote
The product contains the –CONH2 functional group.
35
What type of **mechanism** occurs when **amines react with acyl chlorides**?
Nucleophilic addition–elimination
## Footnote
The nucleophile adds to the carbonyl carbon then a leaving group is eliminated.
36
Why is the **carbonyl carbon in acyl chlorides** susceptible to **nucleophilic attack**?
Partial positive charge
## Footnote
The electronegative oxygen withdraws electron density from the carbonyl carbon.
37
What **product** forms when a **secondary amine reacts further with a halogenoalkane**?
Tertiary amine
38
What **product** forms when a **tertiary amine reacts further with a halogenoalkane**?
Quaternary ammonium salt
39
What is the functional group of a **secondary amine**?
–NHR
## Footnote
Two alkyl groups bonded to the nitrogen and one hydrogen bonded.
40
What is the functional group of a **tertiary amine**?
NR₂
## Footnote
Three alkyl groups attached to the nitrogen.
41
What is the functional group of a **quaternary ammonium salt**?
–NR₄⁺
## Footnote
Four alkyl or aryl groups attached to nitrogen, carrying a positive charge, usually paired with a counterion like Cl⁻.
42
What type of **organic compound** contains both an **amine group** and a **carboxylic acid group**?
Amino acid
## Footnote
Amino acids contain –NH₂ and –COOH functional groups.
43
Why do amino acids show both **acidic and basic behaviour**?
Two functional groups:
* a basic amine group (–NH₂)
* an acidic carboxyl group (–COOH)
## Footnote
This dual functionality allows amino acids to act as both acids and bases, contributing to their role in biological systems.
44
# Fill in the blank:
A molecule containing **both positive and negative charges** is called a _\_\_\_\_\_.
zwitterion
## Footnote
Amino acids commonly exist in this form in solution.
45
# True or False:
In a **zwitterion**, the amino group is protonated and the carboxyl group is deprotonated.
True
## Footnote
The structure contains –NH₃⁺ and –COO⁻ groups.
46
What form does an amino acid mainly exist in at neutral pH?
Zwitterion
## Footnote
The molecule has both positive and negative charges but overall neutrality.
47
# True or False:
In acidic solution, the **carboxyl group** of an amino acid exists as –COO⁻.
False
## Footnote
In acidic conditions it becomes –COOH.
48
# Fill in the blank:
In acidic solution, the amino group of an amino acid exists as _\_\_\_\_\_.
–NH₃⁺
## Footnote
The nitrogen atom becomes protonated.
49
What happens to the **carboxyl group** of an amino acid in **alkaline solution**?
Deprotonated
## Footnote
It exists as the carboxylate ion –COO⁻.
50
# True or False:
In alkaline solution, the **amino group** of an amino acid exists mainly as –NH₂.
True
## Footnote
The proton is removed under basic conditions.
51
# Fill in the blank:
In alkaline conditions, **amino acids** form ions containing _\_\_\_\_\_ and –NH₂ groups.
–COO⁻
## Footnote
The molecule becomes negatively charged overall.
52
Why are amino acids described as **amphoteric**?
React with acids and bases
## Footnote
They can donate or accept protons.
53
What property allows amino acids to form **zwitterions**?
Internal proton transfer
## Footnote
The –COOH group donates H⁺ to the –NH₂ group.
54
What type of **biological macromolecules** are formed from **amino acids** joined together?
Proteins
## Footnote
Proteins are long chains of amino acids linked by peptide bonds.
55
What type of **bond** links amino acids together in proteins?
Peptide bond
## Footnote
A peptide bond forms between the –COOH of one amino acid and –NH₂ of another.
56
# Fill in the blank:
The **linkage** formed between amino acids in proteins is called a _\_\_\_\_\_ bond.
peptide
## Footnote
This bond forms through a condensation reaction.
57
# True or False:
Formation of a **peptide bond** involves the removal of a molecule of water.
True
## Footnote
It is a condensation reaction between the carboxyl and amine groups.
58
What level of **protein structure** refers to the sequence of amino acids in the chain?
Primary structure
## Footnote
This is determined by the order of amino acids in the polypeptide.
59
# True or False:
The **α-helix** and **β-pleated sheet** are examples of secondary protein structure.
True
## Footnote
These structures arise from hydrogen bonding in the backbone.
60
# Fill in the blank:
Hydrogen bonding stabilises the _\_\_\_\_\_ structure of proteins.
secondary
## Footnote
These bonds form between the C=O and N–H groups in the chain.
61
What type of **bond** can form between sulfur atoms in certain amino acids?
Disulfide bond
## Footnote
These S–S bonds help stabilise protein structure.
62
# True or False:
**Disulfide** bonds help maintain the **tertiary structure** of proteins.
True
## Footnote
They form cross-links within the folded protein molecule.
63
# Fill in the blank:
The **three-dimensional folding** of a protein molecule is called its _\_\_\_\_\_ structure.
tertiary
## Footnote
This structure results from interactions between side chains.
64
What **process** breaks peptide bonds to release individual amino acids?
Hydrolysis
## Footnote
Water reacts with the peptide bond to split it.
65
What chromatographic **technique** is used to separate amino acids in the laboratory?
Thin-layer chromatography
## Footnote
Amino acids are identified using their Rf values.
66
What type of **biological molecules** act as catalysts in living organisms?
Enzymes
## Footnote
Enzymes speed up biochemical reactions without being used up.
67
What type of **macromolecules** are enzymes made from?
Proteins
## Footnote
Their structure is formed from folded polypeptide chains.
68
# Fill in the blank:
The **region** of an enzyme where the **substrate binds** is called the _\_\_\_\_\_ site.
active
## Footnote
This site has a specific shape complementary to the substrate.
69
# True or False:
Enzymes act as **biological catalysts**.
True
## Footnote
They increase reaction rate by lowering activation energy.
70
What molecule binds to the **active site** of an enzyme during a reaction?
Substrate
## Footnote
The substrate fits into the enzyme’s active site.
71
# True or False:
Enzyme active sites are **stereospecific**.
True
## Footnote
They can only bind molecules with the correct three-dimensional shape.
72
# Fill in the blank:
Enzymes are able to recognise specific molecules due to the _\_\_\_\_\_ of the **active site**.
shape
## Footnote
The active site is complementary to the substrate.
73
Why can an enzyme bind only one **enantiomer** of a molecule?
Enzyme's active site is **stereospecific**.
## Footnote
Only one mirror-image form fits the active site correctly.
74
# True or False:
Enzyme inhibitors work by blocking the **active site** of an enzyme.
True
## Footnote
This prevents the substrate from binding.
75
# Fill in the blank:
A drug that prevents **substrate binding** by occupying the active site acts as an enzyme _\_\_\_\_\_.
inhibitor
## Footnote
It reduces or stops enzyme activity.
76
What concept describes the matching **shapes** of enzyme active sites and substrates?
Lock-and-key model
## Footnote
The substrate fits precisely into the active site.
77
How can computers assist in **modern drug development** targeting enzymes?
Molecular modelling
## Footnote
Computer simulations help design molecules that fit enzyme active sites.
78
What large **biological molecule** carries **genetic information** in living organisms?
DNA
## Footnote
DNA stands for deoxyribonucleic acid.
79
What are the **repeating units** that make up **DNA** called?
Nucleotides
## Footnote
DNA is a polymer formed from many nucleotide monomers.
80
# Fill in the blank:
Each **nucleotide** contains a phosphate group, a pentose sugar and a _\_\_\_\_\_.
base
## Footnote
The base can be adenine, thymine, cytosine or guanine.
81
# True or False:
The sugar present in DNA nucleotides is **2-deoxyribose**.
True
## Footnote
It is a five-carbon sugar lacking one oxygen atom compared with ribose.
82
What are the **four nitrogen-containing bases** found in DNA?
* Adenine
* Cytosine
* Guanine
* Thymine
## Footnote
These bases attach to the sugar component of the nucleotide.
83
# True or False:
DNA consists of a **single long chain** of nucleotides only.
False
## Footnote
DNA forms two complementary strands.
84
# Fill in the blank:
The **backbone of a DNA** strand consists of alternating _\_\_\_\_\_ and sugar units.
phosphate
## Footnote
These form the sugar–phosphate backbone of the molecule.
85
What **shape** is formed when two DNA strands wind around each other?
Double helix
## Footnote
The two strands twist together in a helical structure.
86
# True or False:
**Hydrogen bonds** hold the **two strands of DNA** together.
True
## Footnote
These bonds form between complementary bases.
87
# Fill in the blank:
Adenine pairs with _\_\_\_\_\_ in DNA.
thymine
## Footnote
These bases are connected by hydrogen bonds.
88
Which base pairs with **guanine** in DNA?
Cytosine
## Footnote
G–C pairs are also held together by hydrogen bonds.
89
Why are the two strands of DNA described as **complementary**?
Specific base pairing
## Footnote
Each base forms hydrogen bonds with only one specific partner.
90
What **platinum(II) complex** is commonly used as an anticancer drug?
Cisplatin
## Footnote
Cisplatin contains Pt(II) coordinated to two chloride and two ammonia ligands in a cis configuration.
91
How does cisplatin interfere with cancer cell **DNA**?
Ligand replacement with guanine
## Footnote
Cisplatin forms covalent bonds between platinum and nitrogen atoms on guanine bases.
92
# Fill in the blanks:
By binding to DNA, cisplatin prevents _\_\_\_\_\_ _\_\_\_\_\_ of cancer cells.
DNA replication
## Footnote
Cross-links distort the DNA structure, stopping replication.
93
# True or False:
Cisplatin forms bonds with **adenine** in DNA to inhibit replication.
False
## Footnote
Cisplatin primarily binds to guanine nitrogen atoms.
94
What type of **chemical reaction** occurs between cisplatin and DNA?
Ligand substitution
## Footnote
Chloride ligands are replaced by nitrogen atoms in DNA.
95
# True or False:
The **cis configuration** of cisplatin is important for its activity.
True
## Footnote
The cis arrangement allows cross-linking of adjacent guanine bases.
96
# Fill in the blank:
Drugs like **cisplatin** can have adverse effects because they also affect _\_\_\_\_\_ cells.
healthy
## Footnote
Rapidly dividing normal cells can be damaged, causing side effects.
97
Why must the benefits and risks of **cisplatin** be carefully assessed?
Balance of therapeutic effect vs toxicity.
## Footnote
It can kill cancer cells but also harm normal cells.
98
# True or False:
Cisplatin is selective only for **cancer cells** and does not affect normal cells.
False
## Footnote
Some normal rapidly dividing cells are also affected.
99
# Fill in the blank:
**Cisplatin** prevents DNA replication by forming covalent cross-links between _\_\_\_\_\_ bases on DNA.
guanine
## Footnote
Cross-linking distorts the double helix and blocks replication.
100
What is the **primary target of cisplatin** inside a cell?
DNA
## Footnote
Binding to guanine bases disrupts replication and transcription.
101
Why does **cisplatin** cause side effects such as nausea and kidney damage?
Non-specific toxicity
## Footnote
Healthy cells that divide rapidly or process the drug can be affected.
102
How can you visualise **amino acids** on a **TLC plate**?
Spray with ninhydrin or view under UV light.
A-Level Chemistry (WJEC - Eduqas)
flashcards
Decks in class (25)
# Cards
-
Physical Chemistry: Atomic Structure50
-
Physical Chemistry: Amount of Substance47
-
Physical Chemistry: Bonding and Structure90
-
Physical Chemistry: Energetics62
-
Physical Chemistry: Kinetics55
-
Physical Chemistry: Equilibria (Qualitative)24
-
Physical Chemistry: Equilibria (Quantitative)12
-
Physical Chemistry: Acids, Bases and Buffers69
-
Physical Chemistry: Thermodynamics27
-
Physical Chemistry: Redox and Electrochemistry63
-
Inorganic Chemistry: Periodicity22
-
Inorganic Chemistry: Group 2 and Halogens55
-
Inorganic Chemistry: Period 3 and Oxides35
-
Inorganic Chemistry: Transition Metals134
-
Inorganic Chemistry: Qualitative Analysis20
-
Organic Chemistry: Basic Concepts42
-
Organic Chemistry: Hydrocarbons85
-
Organic Chemistry: Halogenoalkanes and Alcohols79
-
Organic Chemistry: Carbonyl Compounds20
-
Organic Chemistry: Carboxylic Acids and Derivatives25
-
Organic Chemistry: Aromatic Compounds29
-
Organic Chemistry: Amines and Biological Molecules102
-
Organic Chemistry: Polymers24
-
Organic Chemistry: Organic Synthesis12
-
Analytical Chemistry: Spectroscopy and Chromatography62
