Proteins Flashcards
What is the phenotype of an organism determined by?
The proteins produced as a result of gene expression
What is an organisms’s characteristic determined by?
Many biochemical processes which are enzyme controlled
Why does DNA determine an organism’s characteristics?
DNA controls the structure of enzymes
Are enzymes proteins?
Yes
What is phenotype also influenced by?
Environmental factors which can turn genes on or off
What do all proteins contain?
Carbon
Hydrogen
Oxygen
Nitrogen atoms
What is each protein made from?
Amino acids linked by peptide bonds to form polypeptide chains
What forms polypeptide chains?
Amino acids linked by peptide bonds
How many types of amino acids are there?
20
During protein synthesis, what does the sequence of DNA bases determine?
The sequence of amino acids
What does the sequence of amino acids determine?
Structure and function of a protein
What do polypeptide chains do in a protein?
Coil and fold into 3D shapes as their amino acids interact with the cell environment
Why do polypeptide chains coil and fold into 3D shapes?
As their amino acids interact with the cell environment
What are the 3D shales held together by?
Hydrogen and other bonds between individual amino acids
What are structural proteins mostly made of?
a helices arranged in parallel
Give examples of structural proteins (2)
Keratin
Collagen
What are polypeptide chains in globular proteins?
a helices folded into 3D spherical shapes, held together by hydrogen and other bonds
Give examples of 3 globular proteins
Enzymes
Hormones
Antibodies
What do many protein functions depend on?
The precise 3D shape of the molecule
What are haemoglobin sub-units folded into?
A spherical shape with a non-protein part with iron added
What do four of these folded haemoglobin sub-units make?
One haemoglobin molecule
What can be used to separate charged molecules?
Gel electrophoresis
How does gel electrophoresis separate charged molecules?
Using an electric current to force them to move through a gel
What gets dropped first?
Large molecules
How are proteins treated?
To give them a uniform negative charge, and can be separated by size and weight
