B1.2 Protiens Flashcards
what are Proteins
Proteins are polymers (and macromolecules) made of monomers called amino acids
what determines a Proteins shape and therefore its function
The sequence, type and number of the amino acids within a protein
why are Proteins extremely important in cells and examples of protiens
all of the reactions necessary for life are dependent on the function of proteins
- Enzymes
- Cell membrane proteins (e.g. carrier)
- Hormones
- Transport proteins (e.g. haemoglobin)
- Structural proteins (e.g. keratin, collagen)
- Contractile proteins (e.g. myosin)
oteins
what are Amino acids
monomers of polypeptides
how many amino acids found in polypeptides common to all living organisms
There are 20 amino acids found in polypeptides common to all living organisms
The general structure of all amino acids
central carbon atom, the alpha carbon, bonded to:
An amine/amino group -NH2
A carboxylic acid/carboxyl group -COOH
A hydrogen atom
R group
what is the r group
a side chain specific to each amino acid that gives particular chemical properties to that amino acid
how is a Peptide bond formed
condensation reaction of 2 amino acids resulting in the production of H2O
what is a condensation reaction
when two aminos combine to produce water
Dipeptides
formed by the condensation of two amino acids
alpha carbon
connects amine groups with carboxylic group as well as R group and a hydrogen
polar amino
polar if there is either an OH or NH in the R chain
non polar amino acid
No OH or NH in the r chain
essential amino
an amino acid that our body can’t produce so we need to consume
non essential
what our body produces and doesn’t need to consume
how to calculate amino acids
20^x
oligopeptide
2-20 amino acids
polypeptide
more than 10 amino acids
tripeptide
condensation reaction between dipeptide and amino acids results in tripeptide
peptides of three amino acid residues
peptide linkage
a covalent bonding of the amino group of one amino acid to one of the carboxyl group of another
Role of proteins
versatile
some examples -
Speeding up cellular reactions
blood clotting
cell adhesion
hormones
cell receptions
what is insulin
A hormone produced and secreted by cells in the pancreas
primary structure of a protein
chains of amino acid
secondary structure of a protein
helix formed by amino chains
tertiary structure of a protein
polypeptide chain
quaternary structure of a protein
assembled structures
denaturations
when protiens start to break apart and become undone due to changes in temp and PH
how can heat cause denaturations
causes vibrations between the molecule that can break intermolecular bonds or interactions
examples of polypeptides
insulin
beta endorphin
alpha amylase
titin
what does insulin bind to
Binds to insulin receptors (on liver, fat and muscle cells) causing absorption of glucose from the blood
what is insulin composed off
Composed of 2 polypeptide chains as a short, globular protein
