Unit 8 Flashcards
Amino acids and carbohydrates
What are essential amino acids?
Ones which our bodys cant make
What amino acid is not chiral?
Glycine
Are amino acids water soluble?
Yes
Amino acids can act as an acid or a base whats this called?
Amphoteric
What is the isoelectric point and what form do amino acids take at this point?
It is the pH when amino acids are neutral. When they are neutral they are in Zwitterionic form
What form are amino acids in when they are neutral?
Zwitterionic
What bonds are in amino acids?
Amide/peptide bonds
Why does the amide bond have c=n character?
Resonance
Where does the peptide bond form in an amino acid?
Between the carbonyl c (c=o) and the NH group
What gives amino acids high boiling points?
They can form hydrogen bonds, this is also how they coil
What is electrophoresis?
Where charged molecules move in response to an electric field. The rate in which they move depends on charge, weight, size. It can separate them out
What is an enzyme?
Biological catalyst
How do enzymes work?
They reduce the activation energy needed for a reaction
How can enzymes be denatured?
pH
Temperature
Salt concentration
What is lock and key theory?
Shape of substrate is complimentary to the active site
Enzyme substrate complex is formed
Products have different shape
Explains enzyme specificity and why activity decreases after denature
What is the induced fit hypothesis
The active site and substrate aren’t exactly complimentary
But the active site changes shape in the substrate presence
What is a carbohydrate?
Contains C, H, O
has the C=O and OH (may contain NH)
What is an enantiomer?
Two stereoisomers that are mirror images of each other that aren’t superimposable
What is an epimer?
A type of stereoisomer
It has multiple stereocenters But only differ at one Stereogenic centre
What is an anomer
stereoisomer that differs in the way the OH is pointing (up or down)
Why is b glucopyranose the more stable structure?
less steric hinderance
What is epermirization?
Deprotonating the carbohydrate then reprotonating for a different product
Why are amines basic?
They can accept a proton due to lone pairs on nitrogen
What two functional groups does an amino acid posses?
An acid and an amine
Are amino acids usually optically active?
Yes
What is an alpha helix held together by?
Hydrogen bonds
How is a peptide written. (what side is C and N)
C is on the right hand.
N is on the left hand
How can you abbreviate a peptide
3 or 1 letter for each amino acid
What is the most stable form of cyclic glucose?
B-glucopyranose because the side group in equatorial position
What is the general formula of a monosaccharide
CnH2nO
