Amino Acids and Proteins Flashcards
What is DNA made up of?
Nucleotides, amino acids, sugars
What structure does DNA form?
Double-helix
Describe a Hydrogen bond
Forms between hydrogen and either oxygen, nitrogen or fluorine. It forms a polar bond using the high electronegativity.
Describe an ionic interaction
A positively charged atom will be attracted to a negatively charged atom.
Describe a hydrophobic interaction
Water is excluded
Describe a Van der Waals interaction
Present between every molecule that are in close proximity.
What property makes a molecule soluble?
Polarity.
What is meant by an ‘amphipathic’ molecule?
Has both non-polar and polar areas in the same molecule
In a bilayer, which way do the hydrophilic heads face?
Outwards
In a bilayer, which way do the hydrophobic heads face?
Inwards
List 2 properties of molecules that enable them to move through a phospholipid bilayer
Small
Lipid soluble
Hydrophobic
Polar
How do molecules that cannot pass through the bilayer get into a cell?
Carrier proteins
List 3 functions of proteins
Enzymes Support Transport Receptors /
What are proteins made up of?
Amino acids
What are the 4 groups coming off a central carbon atom in an amino acid?
Hydrogen
Carboxyl group
Amino group
A variable R group
Give a definition of a Base with regard to protons
Proton acceptor
Give a definition of an Acid with regard to protons
Proton donator
Which stereoisomer of proteins is found in proteins?
L isomer
How are amino acids classified?
The chemical properties of the R groups
Will a positively charged amino acid have a high or low pK value?
High
If the pH of the solution is less that the pK of the amino acid, what will happen to the amino acid?
The amino acid will be protonated (gain a proton)
Describe a peptide bond
Two amino acids are linked by the removal of water
List 3 properties of a peptide bond
Planar, shorter, rigid
Is a cis or a trans bond found in proteins?
Trans- the C atoms are found on opposite sides of the peptide bond
