Introduction to Proteins Flashcards
Why study proteins?
Proteins are the workhorses of the cell
Proteins carry out or catalyse almost all the processes required to sense and respond to the environment (grow and replicate, make and breakdown molecules, acquire energy to fuel all processes)
What is the structure of a protein?
Proteins are non-branching polymers that form macromolecules
They’re extremely small to the human eye but in a cell are very big
Amino acids are monomers of proteins, peptide bonds join amino acids together to form polymers
Why study the structure of proteins?
Understanding protein function is key to understanding the biochemistry of life
To really understand function you need to know structure
There are many different techniques used to determine protein structures
What are the three types of protein structures?
Skeletal
Ball and Stick
Space-filling
What is the skeletal protein structure?
Only bonds are shown, can’t depict the chemical elements
What is the ball and stick protein structure?
Each bond is shown, spheres where atoms are located which are each colour coded by what element they are
What is the space-filling protein structure?
All atoms are present and shown as spheres of different sizes to show their radius, colour coded by element, lots of variety in how protein structures look
Protein naming
Any protein ending in -ase tells you its an enzyme and are usually named for what they synthesis or what substrate they bind to e.g nitrogenase is an enzyme that binds to or synthesis nitrogen
What protein is used for oxygen transport?
Haemoglobin binds to oxygen in the lungs and carries it in the blood to tissues for use in metabolism. We need oxygen to get delivered to our tissues via oxidative phosphorylation
What protein is used for metabolism of food?
Hexokinase is an enzyme that adds a phosphate to glucose, after glucose is taken up by the cell (so it can’t leave the cell). Kinases are enzymes that usually add phosphate to molecules
What protein is used for digestion of proteins?
Trypsin is an enzyme that breaks down proteins during digestion. Enzymes that breakdown proteins are called proteases (found in stomach and small intestine)
What is HIV protease?
HIV makes a protease that is essential for HIV replication. When there is a bound inhibitor the protease cannot form and HIV cannot spread
What protein is used for digestion of starch?
Amylase is an enzyme that breaks down starch into sugars. It is found in salvia (salivary amylase) as well as in pancreatic juices (pancreatic amylase)
What protein is used for metabolism of alcohols?
Alcohol Dehydrogenase is an enzyme that helps to metabolise ethanol
What membrane protein is used for metabolism and energetics?
ATP synthase is a remarkable membrane protein that generates ATP for use in cellular functions. It rotates in response to a proton gradient creating energy
What protein is used for immune protection?
Antibodies bind to cellular invaders like bacteria and viruses to help protect the body from infection
What two proteins are responsible for replication and maintenance?
DNA polymerase and RNA polymerase
DNA: binds to one strand of DNA and adds complementary strand
RNA: creates single strand of RNA complementary to one of DNA strands
