2A - Protein Structure and Function

Question 1

protein

Answer 1

a biomacromolecule
made of amino acid chains folded
into a 3D shape

Question 2

polypeptide

Answer 2

 a long chain of amino
acids. Proteins can be made of one
or many polypeptides

Question 3

proteome

Answer 3

all the proteins that are
expressed by a cell or organism at
a given time

Question 4

give some examples that exhibit the diversity of use of proteins

Answer 4

they act as enzymes, hormones, for transport, structure, storage and defence etc

Question 5

what is an antibody

Answer 5

 a protein produced by
plasma cells during the adaptive immune response that is specific to an antigen and combats
pathogens in a variety of ways.
Also known as immunoglobulin

Question 6

amino acids consist of

Answer 6

central carbon bonded to a hydrogen atom, a carboxyl group (COOH), an amino group (NH2), an R group (specific to each protein)

Question 7

explain monomers and polymers with respect to proteins

Answer 7

amino acids are the monomers of proteins - they have repeating base structure and can act as repeating subunits
they join to make polymers aka polypeptides aka proteins

Question 8

how do amino acids bond together

Answer 8

at the ribosome via condensation reactions - forms peptide bond

Question 9

condensation reaction

Answer 9

a reaction
where two monomers join to form a larger molecule, producing water
as a by-product

Question 10

what are the four levels of protein structure

Answer 10

primary (sequence of amino acids), secondary (arrangement into alpha-helices, beta-pleated sheets, or random coils ), tertiary (functional 3D shape of the protein), quaternary ( bonding of multiple polypeptide
chains together)

Question 11

explain secondary protein structure and how it occurs

Answer 11

where the
amino acid chain folds or coils to form either alpha-helices, beta-pleated sheets, or random coils.
by the forming of hydrogen bonds between amino acids of its different sections.

Question 12

explain tertiary protein structure and how it occurs

Answer 12

the overall
functional 3D shape of a protein
- when the secondary structures further fold by forming interactions and bonds between amino acids and R-groups of its different sections.
- Disulphide bonds may form between cysteine amino acids due to the
presence of sulphur atoms in their R-groups to
further stabilise the protein’s 3D structure.

Question 13

explain quaternary protein structure and how it occurs

Answer 13

optional
two or more tertiary polypeptide chains join
they may have a prosthetic group (non protein group bound to protien)

Question 14

How does the primary structure of a protein determine its final functional structure and diversity?

Answer 14

The primary structure, determines how the R-groups interact with each other.
different bonds drive the protein to fold into specific 3D structures,
resulting in its functional tertiary or quaternary structure. This ability to form countless combinations of amino acids enables the functional diversity of proteins.

Question 15

What are the consequences of changes to the primary sequence of amino acids on protein folding and function?

Answer 15

Changes to the primary sequence of amino acids can alter how R-groups interact, preventing the protein from folding correctly into its functional structure. This misfolding can stop the protein from functioning normally.

Question 16

Suggest how the functional diversity of proteins arises.

Answer 16

the functional diversity of proteins arises through the ability to create many combinations of amino acids and polypeptide chains of differing lengths, thereby allowing proteins to fold into different functional structures.