Unit 4.7 Amino Acids Flashcards
WELCOME
get out
Define amphoteric
Can react both as base and acid
Define zwitterion
(3 things)
- Dipolar ion
- Both positive & negative charge
- Resulting in neutral molecule
How can u tell it’s an α-amino acid?
(3 things)
- H2N on the left
- COOH on the right
- Quite obscure…
What classifies an α-amino acid?
(3-way)
- It’s on the α-carbon
- to the carboxylic acid
What is the general formula for an α-amino acid?
CHR(NH2)COOH
Draw displayed formula of general formula for an α-amino acid
(Whiteboard)
Lol
What is the simplest amino acid?
(2-tings)
- Glycine
- R group is just H
Draw structural formula of glycine “3D”
(Whiteboard
Stage is urs per se?
How does the presence of an amine group allow amino acids to also act as a base?
(2-way)
- Lone pair on nitrogen can act as a base
- Accepting a proton/donating an electron pair
What allows the amino acid to be amphoteric?
- Base (Nitrogen lone pair)
- Acid (Carboxylic acid prob)
Show with a diagram, the amphoteric behaviour glycine
State what the result is?
Alas, the zwitterion
Draw the zwitterion version of alanine (R=CH3)
(Whiteboard)
(Just use that as foundation incase of other “zwitterions”)
The stage is always urs
Explain whether m.p of amino acid is high or low?
(3 things)
- Much higher up
- Can form ionic bonds with neighboring ions
- Due to charge
How are amino acids also soluble in water?
(3t hings)
- Can do hydrogen ponds
- They’re polar molecules
- Dissolves within water
How can different amino acids have different solubility?
(1 thing, 1 imp)
- Based on chain length
- Length ∝ 1/solubility
Define isoelectric points
(2-way)
- The pH value at which
- the molecule carries no electric charge
The biggest regret, not listening
I’ll somehow draw this BUT, hopefully that next specific lesson comes in clutch man
What is a zwitterion?
Idk the full real answer… BUT:
- seems to be the “isoelectric point”???
- In the amino acids, the ones with an electron negative O- (Dipole type shi)
- Involves with the different pH (acidic and alkaline type shi)
How to draw the zwitterion versions of an amino acid?
(2-way)
- Turn their OH
- … an O-
- More H into the N (+NH3)
What may happen to a zwitterion of an amino acid if turned more acidic?
(2 things)
- O- to OH
- NH2 to N+3
What may happen to a zwitterion of an amino acid if turned more alkaline?
(2 things)
- O- stays the same
- N+3 to NH2
Show me the amide group?
-NH-C(=O)-
What’s the amide group called in the “biology section”?
Dipeptides
How is an amide group formed?
(or dipeptide if u want)
- 2 amino acids joining up
- Via condensation reaction
Define condensation reaction?
(3-way)
- Formation of an ester
- and a small molecule
- e.g. H2O
Ala = ?
(Amino acid variation)
-CH3
Gly = ?
(Amino acid variation)
-H
Ser = ?
(Amino acid variation)
-CH2OH
Phe = ?
(Amino acid variation)
-CH2-BENZENE
Asp = ?
(Amino acid variation)
-CH2-COOH
Cys = ?
(Amino acid variation)
-CH2-SH
Draw the formation eqn of a dipeptide from alanine and alanine
(Whiteboard)
Stage is yours
Draw the formation eqn of a dipeptide from a glycine and glycine
(Whiteboard)
Stage is yours again
What type of reaction takes place for the formation of polypeptides?
Condensation polymerisation
Just, well, generally know how polypeptides are formed, linked, chained, whatever
How lazy of u
Explain the huge variety of different proteins
(3-way)
- 20 different amino acids
- can form a large number
- of formations/combinations
What are the 3 protein structures?
- Primary
- Secondary
- Tertiary
Simple definition of primary structure?
(Protein structure)
Amino acid sequence
What are primary structures?
(Protein structures)
(2-way + 2-way)
- Takes consideration the order of
- amino acids in chain
- Structure held together by covalent bonds
- such as peptide bonds
Simple definition of secondary structure?
(Protein structure)
(LIL CHECK UP NOOOOO)
Wha
What are secondary structures?
(Protein structures)
(3-way)
- Defined by pattern of hydrogen bonds
- between amine hydrogen and carbonyl oxygen atoms
- in peptide back bone
What are the 2 common types of secondary protein structures?
- α-helix
- β-pleated sheet
Describe secondary, α-helix?
(Protein structures…. secondary edition)
(1 thing +
2-way +
3-way)
- Protein chain wound into a coil (like loose spring)
- Coil runs in clockwise direction
- as it goes away form you
- Hydrogen from amide on one section of chain…
- forms hydrogen bond with oxygen
- from carbonyl group further along the chain
Describe secondary, β-pleated sheet?
(Protein structures… secondary edition)
(2-way +
4-way)
- Chains are folded
- So they lie alongside each other
- Likewise, hydrogen from amide on one section of chain…
- forms hydrogen bond with oxygen
- from carbonyl group
- as chain folds back on itself
Simple definition of tertiary structure?
(Protein structures)
(2-way…)
- Overall folding of the chain
- with interactions such as…
What are tertiary structures?
(Protein structures)
(1 + () + 2-way)
- A description of the way the whole chain
- (including secondary structure)
- folds itself into its
- final 3-dimensional shape
How is the tertiary structure of a protein held together?
(Protein structures)
(2-way)
- By interactions between the side chains…
- the “R” groups
What are the 4 interactions that there may be in tertiary structures?
(Protein structures)
- Ionic interactions
- Hydrogen bonds
- Van der Waals dispersion forces
- Sulfur bridges
Explain ionic interactions?
(Protein structures… tertiary interactions)
(2-way + 2-way)
- Due to additional acid or amine groups
- within the R groups
- Proton exchange can occur leaving
- COO- and NH3+
Explain hydrogen bonds?
(Protein structures… tertiary interactions)
(2-way… hm)
- Hydrogen bonds forming between
- H and O in different R groups
Explain Van der Waals dispersion forces?
(Protein structures… tertiary interactions)
(3-way)
- Large R groups containing
- lots of electrons that can
- cause these temporary dipoles
Explain sulfur bridges?
(Protein structures… tertiary interactions)
(3-way)
- Between 2 cysteine
- as they contain an R group of
- CH2SH
Explain why hydrogen bonding occurs in secondary protein structures, such as in an α-helix?
(Protein structures per se)
(3 things)
- O of C=O H-bonding to H on N-H
- O of C=O and side chains
- Amines and alcohols/carboxylic acids of side chains
What is the role of proteins in living systems?
(2 things)
- Enzymes
- aka biological catalysts
How does an enzyme speed up the rate of a chemical reaction?
(2-way)
- Lowers activation energy
- by offering an alternate pathway
What are the 3 ways enzymes are needed in typical industry?
- Brewing
- Dairy
- Laundry
Explain brewing and it’s enzyme importance?
(Prob check up, but don’t sell)
… Yeast.
Explain dairy and it’s enzyme importance?
(Still check up, don’t sell as well)
… Fermentation process
…. create cheese and yoghurt
Explain laundry and it’s enzyme importance?
(Check per se, what does per se even mean)
- Biological washing powder
- Something to do with how they eat up oils and fats
- In addition, save money by not needing heat
All u have is a major check up on zwitterion, not so much on that “simple def. of secondary structures”. Otherwise tho, expect the unexpected
Correct
