Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry (A2) > Amino Acids > Flashcards

Amino Acids Flashcards

1
Q

What are the two functional groups of amino acids?

A

NH2 and COOH

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

How many naturally occurring amino acids are there in a human body

A

20

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

What type of amino acids are found in the body?

What does this mean about their structure?

A

Alpha-Amino aicids

NH2 functional group is on the adjacent carbon to COOH

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

Draw a general formula for alpha amino acids

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

Are alpha amino acids Chiral?

A

Yes , one carbon has four different subsistent

Exception = Glycine where R = H

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

Write the equation for the first step of industrial amino acid synthesis

A

Aldehyde + Nitrile to produce an amino nitrile

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

Write an equation for the second step of industrial amino acid synthesis
And any conditions

A

Amino nitrile (in step 1) + Hydrochloric acid + Water —> Amino acids + Ammonium Chloride
Hydrolysis, use dilute HCl and under reflux

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

In what form do amino acids exist as solids?

A

Alpha amino acids as zwitterions in an ionic lattice - High melting and boiling point

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

What colours are zwitterions at room temperature

A

White solids

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

Do Zwitterions disolve in water

A

Yes, zwitterions have permanent +Ve and -Ve charges which causes electrostatic attraction between the +Ve charge and the lone pair within water molecules

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

Define a zwitterion

A

Ions which both have a permanent positive and negative charge, but are neutral overall

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

How do zwitterions occur in amino acids

A

COOH is deprontonated
NH2 is protonated
When the acid has reached its isoelectric point in ph

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

What happens to amino acids when the ph is lower then its isoelectric point

A

NH2 group is protonated

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

What happens to amino acids when it’s ph is higher then the isoelectric point

A

COOH is depotonated

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

Draw a peptide linkage

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

What is a dipeptide
Draw a general one for amino acids

A

Two amino acids bonded together
Under a peptide link

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

What name is given to amino acid chains up to 50 monomers

A

polypeptides

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

What name is given to chains of amino acids with more then 50

A

proteins

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

What is the process in which polypeptides are broken down into their constituent amino acids

A

Hydolysis

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

What conditions are needed for the hydrolysis oof amino acid chains

A

6moldm^-3 HCl
Reflux for 24h
110 Degrees

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

Draw the formation of a peptide link using trio generalised amino acids

A

hydrolysis

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

What is the primary structure of a protein?

A

The sequence of amino acid monomers along the peptide chain bonded by covalent bonds.

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

How is the primary structure of an amino acids represented

A

Sequence of 3 letter add revisions of amino acids

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

What is the secondary structure of a protein

A

The shape of the protein chain
Alpha Helix or Beta pleated sheet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the two options for the secondary structure of a protein
Alpha-helix shape or beta-pleated sheet
26
How is the secondary structure held together
Hydrogen bonding Between C=O and N-H on the polypeptide backbone
27
What is the tertiary shape of a protein
Alpha helix or beta pleated sheet is folded into a. complex 3D shape
28
How is the tertiary structure held together
a combination between Hydrogen bonding Ionic interactions between R groups Sulphur-Sulphur bonding (disulphide bridges) Van Der Waals
29
Why is tertiary structure important
The shape of the protein molecules is vital in their function Eg active sites in enzymes
30
How can amino acids. be attracted to each other
Hydrogen bonding Ionic interactions between groups or side chains Sulphur-Sulphur/ Disulphide bridges 2 S atoms are oxidised to form an S-S bond
31
What is wool How is it held together
Protein fibre with a secondary alpha helix structure held together by hydrogen bonds
32
What does the structure and bonding in wool mean for its properties
wool= Protein fibre with a secondary alpha helix structure held together by hydrogen bonds Can be stretched and elastic —> Hydrogen bonds extend and when the force is removed they return to their original shape Wash too hot and the H bonds permanently break so the garment looses its shape
33
What is a Thin layer Chromatography plate made of
Plastic sheet coated with silica ( SiO2) This is the stationary phase The solvent is the mobile phase
34
Amino acids have basic and acidic properties what is this quality called?
Amphoteric
35
How would you cary out thin Layer Chromotography
Spot the samples onto a pencil line a few cm above the talc plate Place this in as breaker or tank, with solvent level below the pencil line Ensure there is a lid on the beaker to keep the inside saturated with solvent vapour Wait until sol;vent is almost a that the top of the TLC plate Remove from beaker and analyse
36
How do you name an amino acid using IUPAC
1) Find longest carbon chain - carboxylic acid 2) Number carbons - 1 is the carboxyl group carbon 3) Note the carbon number where the amide groups lie 4) Use prefix amino over amide 5) Name other groups that aren’t COOH or NH2 first
37
Why does TLC separate amino acids
Solvent carries amino acids up the TLC plate. The rate of moment depends on the balance between the amino acids affinity for the stationary and the affinity for mobile phase
38
What is the isoelectric point
Zwitterions only exist in an amino acid at its isoelectric point Isoelectric point = The PH at which the average overall charge of a zwitterion is zero as there is a permanent positive charge at the amine group and a permanent negative charge at the carboxylate group
39
Name 2 ways to analyse a sample of TLC chromotography
Amino acids are colourless Spray on ninhydrin - Amino acids are colourless, the vapours of this substance sticks to the chemicals turing the amino acids purple Add fluorescent dye to the stationary phase, Shine UV light, Colourless amino acids block the flow from the fluorescent dye
40
How do you calculate an Rf Value
Distance moved by substance / Distance moved by solvent
41
How do you find the primary structure of a protein
Reflux with 6M HCl for 24h to break down the peptide links, separating it into its monomers Carry out TLC to find the number and types of amino acids present
42
How do you find the secondary/ tertiary structure of a protein
X-ray Crystallography
43
What is an enzyme
Biological catalyst Specialised to increase the rate of reactions of a specific reaction. Made of amino acids
44
Describe the structure of an enzyme How does its structure helps its function
Globular protein with a creft in it know as the active site. This active site is a unique shape that is designed to fit a very limited umber of substrate Has a chiral centre 2) active site is a unique shape that is designed to fit a very limited umber of substrate held at the perfect orientation for them to react/bind (stereospecificity) Locks and key hypothesis.
45
How else do enzymes increase the rate of reaction
binding molecules to the active site via forming temporary bonds with intermolecular forces This weakens the bonds int the molecules, promotes electron movement and lowers the acitvation energy
46
What does the stereospecificity of an enzyme mean? How does this effect naturally occurring molecules
Active sites are so selective of the shape of the substrates that can fit, it only catalyses reactions of a specific enantiomer but not the other one. Most naturally occurring molecule have a much larger abundance of one enantiomer compared with he other due do an enzymes stereospecificity
47
How does enzyme inhibition work
A molecule with a a very similar shape and structure to the substrate is devised Binds to the enzyme’s active site very strongly Blocks the active site As substrate cannot adsorb to the active site so reaction cannot be catalysed
48
What drug works via enzyme inhibition?
Penicillin
49
What causes enzymes to Denature
Change in Temperature or PH
50
What does DNA stand for
Deoxyribonucleic Acid
51
What consititutes as a nucleotide
A phosphate ion A Sugar (2-deoxyribose) A Base (Adenine cytosine guanine or thymine)
52
Draw the general structure for a nucleotide
53
What forms between bases of adjacent nucleotides
Hydrogen bonding
54
Which bases pair up between nucleotides
A & T C & G
55
How does DNA Polymerise? What type of polymer chain is this
OH on phosphate OH on 3rd Carbon on 2 deoxyribose react to eliminate a molecule of water. Condensation Polymer
56
What determines the properties of the DNA molecule
Unique order of bases
57
Explain the Structure of DNA
2 strands of amino acids held together by hydrogen bonding between complimentary base pairs wound together in a double helix
58
How is DNA Replicated exactly when Cells Divide
DNA Helixase unzips the chain by breaking the hydrogen bonds holding the base pairs together Free nucleotides that are activated attach to their complimentary base pairs The activated nucleotides bind to their complimentary bases with he aid of DNA Polymerase Bases link together by forming the sugar phosphate backbone
59
How does the body use the information stored in DNA
Template for arranging amino acids into specific proteins, such as enzymes or flesh
60
Draw the Structure of CISplatin
61
What is Cisplatins Function? How does it do this? (3)
Anti-Cancer Drug Bonds to strands of DNA to distort shape and prevent cell replication. It bonds to the Nitrogen atoms on 2 adjacent Guaneines. Nitrogen atoms replace the Chlorine ligands in a ligand substitution reaction
62
What are the Cl- ligands are able to be replaced by Nitrogen on the base (Amino acids)
N atoms on the Guanine have lone pairs of electrons ions that can coordinately bond to the platinum N atoms can donate electrons more readily so it replaces the chlorine ligands
63
What are the Disadvanatges to cisplatin
Affects Healthy cells that are replicating quickly as well as the cancer cells such as hair follicles
64
ph= 11.8
1.26 x 10^-24
65
Enzyme has a stereo-specific active site G-enantiomer has the correct stereochemistry and the only accepted complimentary shape
66
State the meaning of the term complimentary in reference to DNA strands
complimentary means that the two strands must have base sequences that match A to T and C to G
67
Secondary N & O are very electronegative therefore C=O and N-H are polar bonds These polar bonds are sufficiently polarised to form hydrogen bonding between N & H and O&H on oppposing bases In which a lone pair of electrons on an oxygen atom is strongly attracted to a delta positive hydrogen
68
series of nucleophilic substitution reactions (amine + excess haloalkane = quaternary ammonium ion)
69
Base A Top N-H forms hydrogen bonds with lone pair O of Guanine The lone pair of electrons on N bonds to N-H of Guanine A Lone pair of electrons on O bonds to lower H-N of guanine
70
Draw Hydrogen Bonds between each of the complimentary bases, include where the connection is to the sugar
71
Hydrogen Bonds form between urea and DNA strands Urea has 2 amino groups, that goes in-between the strands to separate them

Chemistry (A2) (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions