Macromolecules-proteins
Learning outcomes
1. List main features of amino acids
2. Describe formation of peptide bonds
3. Outline features of 4 levels of protein structure
4. Define the terms of the motif and domain
5. Give examples of protein functions in the cell
Intro to proteins
Diverse group of macromolecules with range of cellular functions
Enzymes-biological catalysts
Defence- cell surface receptors, globular proteins which recognise foreign microbes and
cancer cells, cell surface receptors from the core of the bodies endocrine and immune
system.
Transport- globular proteins transport small molecules and ions. E.g., haemoglobin
transports oxygen in blood, membrane transports proteins transport ions through
membranes
Structural support- keratin in hair, fibrin in blood clots and collagen
Motion- muscles, contractile proteins
Regulation- intra and inter cellular signals, hormones, transcription factors
Storage- of ions, (iron, calcium) bound to storage proteins
Proteins are polymers
Amino acids are the monomers
Composed of 1 or more long unbranched chain
Each chain is a polypeptide
Made of 20 different amino acids
Amino acids
Central carbon atom
Amino group
Carboxyl group
Single hydrogen
Variable r group
Known as amino acids because contains amino group (-NH2) and acidic carboxyl group (-
COOH)
Amino and carboxyl groups give directionality (n-terminus and c-terminus) to polypeptides
R group is the amino acids personality
20 amino acids are found in proteins
Polypeptides may be composed a few amino acids (oligopeptides) or hundreds or thousands
of amino acids
Unless the r group is an H atom (glycine) amino acid are chiral and can exist as 2
enantiomeric forms D and L
In living systems only L amino acids are found in proteins and D amino acids are rare
Amino group and carboxyl group are always same
The r group differs in all 20 amino acids
Side chain determines whether the AA will polar, non-polar or electrically charged
Learning outcomes
1. List main features of amino acids
2. Describe formation of peptide bonds
3. Outline features of 4 levels of protein structure
4. Define the terms of the motif and domain
5. Give examples of protein functions in the cell
Intro to proteins
Diverse group of macromolecules with range of cellular functions
Enzymes-biological catalysts
Defence- cell surface receptors, globular proteins which recognise foreign microbes and
cancer cells, cell surface receptors from the core of the bodies endocrine and immune
system.
Transport- globular proteins transport small molecules and ions. E.g., haemoglobin
transports oxygen in blood, membrane transports proteins transport ions through
membranes
Structural support- keratin in hair, fibrin in blood clots and collagen
Motion- muscles, contractile proteins
Regulation- intra and inter cellular signals, hormones, transcription factors
Storage- of ions, (iron, calcium) bound to storage proteins
Proteins are polymers
Amino acids are the monomers
Composed of 1 or more long unbranched chain
Each chain is a polypeptide
Made of 20 different amino acids
Amino acids
Central carbon atom
Amino group
Carboxyl group
Single hydrogen
Variable r group
Known as amino acids because contains amino group (-NH2) and acidic carboxyl group (-
COOH)
Amino and carboxyl groups give directionality (n-terminus and c-terminus) to polypeptides
R group is the amino acids personality
20 amino acids are found in proteins
Polypeptides may be composed a few amino acids (oligopeptides) or hundreds or thousands
of amino acids
Unless the r group is an H atom (glycine) amino acid are chiral and can exist as 2
enantiomeric forms D and L
In living systems only L amino acids are found in proteins and D amino acids are rare
Amino group and carboxyl group are always same
The r group differs in all 20 amino acids
Side chain determines whether the AA will polar, non-polar or electrically charged
