Proteins Flashcards
What order of protein structure refers to the order of the sequence of amino acids?
Primary
What order of structure refers to the spatial arrangement of polypeptides in a multi subunit protein?
Quaternary
What is the tertiary structure of a protein?
Spatial arrangement of amino acid residues that are far apart in a linear sequence
What are the two types of secondary structures of a polypeptide?
Alpha helix
Beta pleated sheet
What causes an alpha helix to form?
Hydrogen bonds between N-H and C=O groups
What amino acid is responsible for disulphide bridge formation?
Cysteine
What is glycosylation?
Post-translational modification converting a protein into a glycoprotein
(Protein + carbohydrate)
Where does glycosylation take place in a cell?
ER and golgi apparatus
What is a lipoprotein?
Protein + lipid
Either covalent or non-covalently joined
What is the main use of lipoproteins?
Transport of fats and cholesterol in blood
What is a metalloprotein?
Protein molecule with a metal ion bound to it
What are functions of globular proteins? (5)
Enzymes
Transporters
Messengers
Stock of amino acids
Some structural function - actin etc
What are fibrous proteins generally used for? (4)
Bone matrices
Muscle fibres
Tendons
Connective tissue
Membranous proteins are found on cell membranes and organelle membranes. What are they used for? (4)
Relay signals
Transporters
Enzymes
Cell - cell joining
What type of protein is collagen, and what is used for?
Fibrous
Structural shit
Low vitamin C intake causes scurvy.
What does scurvy do to ye?
Weakargghhhhh collagen fibres
What type of molecule are LDL receptors?
Membraneous glycoproteins
Describe the effect of osteogenesis imperfecta.
Glycine substituted for larger amino acid
Collagen can not fold tightly
Weak and brittle collagen
This leads to weak and brittle bones
What is sickle cell anaemia?
Mutation of gene coding for beta-chain in haemoglobin swaps glutamic acid for valine
Different shaped protein = disfunctional
Haemoglobin polymerises causing RBC’s to change shape
Clinical: Heamolytic anaemia
What is familial hypercholesterolemia?
Autosomal dominant disorder
Mutated LDL receptor gene causes a non-functioning LDL receptor to be produced
Elevated LDL levels in the blood
Cholesterol deposits in arteries, skin, tendons
Cardiovascular disease
