B.1.2 Proteins

Based on the 3rd edition biology textbook written by C.J. Clegg, Andrew Davis, Christopher Talbot

amino acids

amino acids

has an amino group and a carboxyl group, there are 20 different types

peptide linkage

a covalent bonding of the amino group to the carboxyl group of another molecule with a condensation reaction

start of protein

N-terminus

end of protein

C-terminus

protein

a long chain of amino acids that has specific functions

denaturation

a structural change in a protein that results in a loss (usually permanent) of its biological properties

change of ph, temperature, exposure to high wavelengths, concentrated alcohols

primary structure

the linear sequence of amino acids that determines the shape of a protein

secondary structure

the protein sequence interacts with itself, forming hydrogen bonds that are helix-shaped/coiled (alpha) or folded/pleated-sheets (beta)

tertiary structure

forming a 3D structure of a protein through hydrogen, ionic, and bisulfide bonds between cysteine and methionine

quaternary structure

more than one polypeptide chain is combined to form a large protein

haemoglobin

a protein containing iron that facilitates the transport of oxygen in red blood cells

insulin

hormone made on the pancreas that promotes the synthesis and storage of glycogen in the liver and muscle cells

small, compact, parts of building are reusable

collagen

a structural protein found in skin, bones, muscles, and tendons

three polypeptide chains in the shape of a helix, these are coiled with each other, staggered to have no gaps

fibrous

long, coiled, strong, non-soluble

ex: keratin, collagen

globular

sphere, soluble,

ex: insulin, lysozyme, catalase