Biochemistry___Lesson-8___Chapter 3.12 thru 3.14 Flashcards
A molecular machine built from a polymer of amino acids.
Protein
A molecule that behaves as a biological catalyst in a cellular reaction.
Enzyme
A process in which a protein unravels, losing its specific shape, and as a result, its function.
Denaturation
The monomers of protein composed of a central carbon bonded to an amino group, a carboxyl group, a hydrogen, and an R group.
Amino acid
A covalent bond between two amino acids.
Peptide bond
Two bonded amino acids.
Dipeptide
A polymer of amino acids.
Polypeptide
The sequence of amino acids in a polypeptide.
Primary structure
Folded segments of a polypeptide that take the shape of an alpha helix or a beta pleated sheet.
Secondary structure
The overall three-dimensional shape of a protein made from the bonding of secondary structures to each other.
Tertiary structure
The structure of a protein made from more than one polypeptide.
Quaternary structure
Draw from memory the molecular structure of 2 amino acids (label an amino group and carboxyl group) undergoing a dehydration reaction to form a peptide bond.
What is the monomer of proteins?
Amino acids
Draw the molecular structure of an amino acid that has methyl as the R group. Label the amino group, carboxyl group, and R group. What chemical properties does this amino acid have: hydrophilic, hydrophobic, acidic, basic?
Hydrophobic
Amino group is NH2
Carboxyl group is COOH
Methyl is CH3
How can a cell make many different kinds of proteins out of only 20 amino acids?
There is an unlimited combination of amino acids because the number of amino acids in a chain can vary, and the same amino acid can be used many times in a chain.
What determines the function of a protein?
The shape of the protein.
What can cause protein denaturation
Protein denaturation is when a protein unfolds and stops functioning. This can be caused by changes in temperature, pH, or ion concentration, each of which can interfere with the hydrogen bonds that hold together the secondary structure. When these bonds are destroyed the protein unfolds and stops functioning.
What gives an amino acid the chemical properties of hydrophilic, hydrophobic, acidic, or basic?
The chemical nature of the R group. If the R group has an oxygen atom it will be hydrophilic. If the R group is a hydrocarbon, then it will be hydrophobic. Carboxyl groups are acidic and amino groups are basic.
What are the 4 levels of protein structure?
1 - primary
2 - secondary
3 - tertiary
4 - quaternary
What type of bond holds together the primary structure of a polypeptide?
A peptide bond (a type of covalent bond) between the carboxyl group of the backbone one amino acid and the amino group of the backbone another amino acid.
What type of bond holds together the secondary structure of a polypeptide?
Hydrogen bonds between the atoms of the backbone.
What are the 2 types of secondary structure?
Alpha helix and Beta pleated sheet.
Which levels of protein structure requires R group interactions
3 - tertiary
4 - quaternary
A genetic mutation can change the primary structure of a protein. How can this destroy the protein’s function?
R groups determine if the 2 structure will fold into an alpha helix or a beta pleated sheet, although they do not participate in the hydrogen bonds that make 2 structure.
R groups form bonds between each other to create 3 and 4 structure.
If an R group is changed by genetic mutation, and if this results in a change of 2 or 3 or 4 structure, and if that results in a change in the shape of the protein, then the protein will not work.
