Session 5 (Protein Structure And Function + Mitosis) Flashcards
What happens is there are more than 2 centrosomes/ centrioles?
You get multi polar spindles
What are targeted often in cancer treatments?
Mitotic spindles (no cell division=cell death)
Give an example of a drug that interferes with microtubules?
Taxanes (taxol)
What are the two types of chromosome instabilities?
Structural and numerical
What is the molecular glue that holds sister chromatids together?
Cohesin (makes centromere)
What is pK?
The pH at which 50% of an amino acid is deprotonated and 50% is in protonated form
What is the isoelectric point? (pI)
The pH at which a molecule has no net charge
What happens if:
A) pHpK
C) pI<7
D) pI>7
A) amino acid will be protonated
B) amino acid will be deprotonated
C) protein is acidic
D) protein is basic
State the main difference between 2nd and 3rd protein structures?
Secondary- local spacial arrangement of backbone only
Tertiary- spacial arrangement of amino acids that are far apart in structure
What are conjugated proteins?
Proteins with chemical components covalently bonded ie haem, zinc etc
Describe the different types of protein (2)
Fibrous-support, shape, protection,
Long sheets and strands, repeating 2nd structure
Globular- catalysis and regulation
Compact, several structures within
What are electro static interactions?
Interactions involving charge
What bonding do you get at the different protein structure levels?
1- covalent
2- hydrogen
3+4- covalent, ionic, hydrogen, hydrophobic, disulphide
What shape are peptide bonds?
Planar
Why can the bond between 2 amino acids not rotate?
Because the bond is partially double bond (you get resonance)
What conformation do peptide bonds exhibit?
Trans-conformation
Cis is repelled
How are protein structures reached?
Trial and error, localised folding,and with stable conformation, is maintained
What d you call a protein with an abnormal structure?
Amyloid
What do you need to consider when classifying an amino acid? (3)
Charges
Acidity
Interactions (bonding)
What charge do acidic side chains have?
Negative
What are aliphatic molecules?
A hydrocarbon chain
What does an increased ka mean for acids?
It means they’re stronger so dissociate more
