bio molecules proteins Flashcards
what are amino acids?
amino acids are the momomers from which protein are made
they contain a amino group (NH2) carboxylic acid and a different R group
how many amino acids are they
they are 20 amino acids each with a different r group
how are amino acids formed?
they joined by peptide formed by condensation reactions
dipeptide = two amino acids
polypeptide = 3 or more amino acids
what are the structure of proteins determined by?
order and the number of amino acids
bonding present
shape of the protein
primary structure?
order and the number of amino acids in a protein
secondary structure
shape that the chain of amino acids takes -either alpha helix or beta pleated sheet the shape is determined by hydrogen bonding
tertiary structure
3D shape of the protein it can be globular or fibrous
globular protein?
such as enzymes are compact
fibrous protein?
such as keratin are long and thus can be used to form to protect
collagen?
fibrous protein of great strength sue to presence of both hydrogen and coavalent bonds in the structure
collagen molecules wrap around each other and form fibril which form strong collagen fibres
haemoglobin ?
haemoglobin is a water globular soluble protein which consists of two alpha and beta polypeptide chains each containing a ahem group of
it carries oxgyen in the blood as oxygen can bind to the haem (Fe2+) group and oxygen is then released
what is meant by conjugated protein
contains a non protein group
has a prosthetic group eg iron
prosthetic group is attached by covalent bonds
what does fibrous protein that globular protein don’t have?
insoluble
strong
unreactive
why is transcription necessary for polypeptide synthesis
gene is transcribed to mRNA
DNS is too large and cannot leave the nuclear envelope
compare the properties and functions of fibrous proteins with globular proteins in the human body
(fib)
fibrous protein
- insoluble
-elongated
-strong
-flexable
examples:collagen
for connecting the muscle tissues to the bone
compare the properties and functions of fibrous and globular proteins
(globular)
- soluble
-have 3D shape/structure
-hydrophilic structure on the outside
-contains prosthetic group
examples:enzyme
to catalyse reactions and to lower activation energy
why is collagen a fibrous protein
-long chain of amino acids
-no tertiary stucture
-insoluble
-has a structural function (provides strength to artery walls)
why is collagen a strong molecule
many hydrogen bods between polypeptides
