Chapter 4- Protein Structure and Function Flashcards
Give some examples of what proteins do for the cell
Proteins…
- Act as enzymes to catalyze reactions
- Form channels and pumps (Sodium Potassium Pump)
- Carry signals
_________ dictates _________
Structure, Function
The numerous functions of proteins result from what?
The huge amount of shapes that proteins can be
Give examples of proteins
- Enzymes
- Structural Proteins
- Transport Proteins
- Motor Proteins
- Storage Proteins
- Signal Proteins
What determines a proteins primary structure?
The amino acid sequence ( 20 different amino acids, numerous ways to combine them )
What is the sequence of molecules that makes up the backbone?
NItrogen Carbon Carbon
What are the groups of amino acids?
Non-polar, Negatively charged, positively charged, Uncharged Polar
Electrostatic Attractions
positives and negatives coming together
Hydrogen Bond
Form between polar parts of molecule
Van Der Waals Attraction
Anytime two molecules get close together there is a minor attractive force
Hydrophobic Forces
Hydrophobic molecules forced together in an aqueous environment to minimize effect on hydrogen bonded network
How do proteins choose what shape to fold into
They fold into the shape that requires the least amount of energy (AKA Free Energy (G))
Misfolded proteins cause what disorders?
Give Examples
Neurodegenerative disorders
Alzheimer’s, Huntington’s, Scrapie, BSEm CJD
Why are misfolded proteins so dangerous?
They continue to produce copies and create more misfolded proteins (Almost acts like cancer)
What do chaperone Proteins Do?
Hold the proteins in their correct shape as they’re forming
How many amino acids long can a protein be?
30 - 10,000 amino acids long
How many amino acids long can a protein be?
30 - 10,000 amino acids long
What are the two common Secondary Structures that proteins form?
Alpha Helix and Beta Sheets
Where are the side chains in Alpha Helix’s?
Out to the side of the twisty chain
What is the tertiary structure?
The protein folding back on itself AKA the globular structure
How to determine if a protein is a transmembrane protein?
If it has 7 hydrophobic amino acids in a row
What occurs when a charged molecule needs to go through a cell membrane?
Two helices will wrap around each other to minimize exposure of hydrophobic amino acid side chain to aqueous environment
Where are the side chains in beta sheets
Either above or below
Parellel Beta Sheets
Polypeptide chains that run in the same orientation
Antiparallel Beta Sheets
Polypeptides that run opposite directions
Is a folding proteins energetically favorable or unfavorable?
It is energetically favorable because it releases heat and increases the entropy of the universe
