Proteins Flashcards
What are the basic building blocks of proteins?
Proteins are built of amino acids. There are around 20 types of amino acids found in all living organisms.
Proteins vary hugely in function. Give an example of proteins and their function.
An example of a protein is haemoglobin (the thing responsible for blood being red) it is an iron-containing protein that plays a role in the transportation of oxygen in the blood. Another protein: fibrin forms a mesh of threads over the surface of wounds trapping blood cells and forming scabs.
What is the test for protein?
Biuret solution is used to identify the presence of protein. Biuret reagent is a blue solution that, when it reacts with protein, will change color to pink-purple.
About the 20 types of amino acids
All 20 of the amino acids have the same general structure. They contain a carboxyl group (cooh) an amine group (NH2) and an R group (the R group is what decides what amino acid it is). They also contain a Hydrogen atom
What is an R group?
The thing that differentiates the amine groups from each other.
What is a peptide bond?
A chemical bond formed between two amino acids as a result of condensation.
What do you get when you cross two amino acids?
A dipeptide (two amino acids joined by a peptide bond)
What type of reaction do amino acids join to form a dipeptide?
A condensation reaction forms a dipeptide and removes hydrogen but creates a molecule of water
What is primary structure?
The sequence of amino acids in a polypeptide
What is secondary structure?
The shape the polypeptide chain folds into, such as alpha helix and beta pleated sheet
What is tertiary structure?
Gives a protein the characteristic complex, three-dimensional shapes that are closely related to its function.
Other than the R group what influences a protein’s shape?
The order of amino acids determines the protein. Also called the primary structure.
Why is the tertiary structure important?
Tertiary structure is important because it’s closely related to the function of the protein. and the different types of bond between different amino acids which maintain the shape.
What are the three types of bonds in proteins?
Hydrogen bonds
Ionic bonds
Disulfide bridges
Define and explain Hydrogen bonds
Hydrogen bonds form between R-groups of a variety of amino acids. They are weak and easily broken but there are many of them
