Macronutrients - Proteins Flashcards
what elements do proteins contain?
carbon, hydrogen, oxygen but also nitrogen and sometimes sulphur and phosphorus
how many amino acids are in a human?
about 20
what are polymers before they are proteins?
polypeptides
what are fibrous proteins?
structural proteins eg collagen
what are some properties of fibrous proteins?
insoluble in water, strong and tough
how many polypeptide chains does a single fibre consist of?
3 polypeptide chains
what are globular proteins?
metabolic functions eg haemoglobin
what are some examples of globular proteins?
- enzymes, antibodies, hormones eg insulin
what is the shape of globular proteins?
compact and foldedinto 3D spherical molecules
state four differences between haemoglobin and collagen
- h has 4 polypeptide molecules, c has 3
- h - eahc polypeptide is diff, c - each is same
- h associated with non-protein groups, c not associated with non-protein groups
- h quaternary, c secondary
what are the contents in an amino acid?
amino group, r-group (varient), carboxyl group
what do the different r groups do?
make different amino acids
what is the protein bond?
peptide bond
what are the four levels of proteins?
- primary structure
- secondary structure
- tertiary structure
- quaternary structure
what is the primary structure?
the sequence of amino acids in a polypeptide chain (triplet code)
what is the secondary structure?
forming of the primary structure into a 3D shape which is held together by hydrogen bonds eg beta pleated sheets, helixes
what are the forces responsible for the formation of tertiary structure?
hydrogen bonds
ionic bonds
disulphide bonds
covalent bonds
what are tertiary structures also known as?
polypeptides
what is the quaternary structure made up of?
two or more tertiary structure/polypeptides joins together
eg haemoglobin
draw an amino acid
draw the formation of a dipeptide