biochem final free response Flashcards
What is proteostasis?
regulates proteins within the cell in order to maintain the health of the cellular proteome and the organism itself.
You have four different proteins that you want to separate from each other.
Protein A has a pI of 6.8 and a molecular weight of 66,000, Protein B has a pI of 7.0 and
a molecular weight to 125,000, Protein C has a pI of 6.1 and a molecular weight of
50,000 and Protein D has a pI of 10 and a molecular weight of 11,000. What
chromatography technique would you use and why? Can you predict the elution order?
First, use ion exchange chromatography because it can seperate based on the PI and mw.
D pI 10, MW 11,000
B pI 7.0, MW 125,000
A pI 6.8, MW 66,000
C pI 6.1, MW 50,000
How are protein structure described and do all of these levels of structure apply to
all proteins?
classified by primary, secondary, tertiary, quartenary
1- chain of AAs
2- AA’s fold into repeating pattern
3-3d folding pattern of a protein
4- protein with more than 1 amino acid chain
All levels dont have to apply to all proteins.
How does bisphoshoglycerate help oxygen transport in conditions of low partial
pressure of oxygen? Are there other ways that hemoglobin is regulated, if so how?
-BPG does this by binding to hemoglobin and reducing its affinity for oxygen
-hemoglobin is also regulated by co2
How does one determine if one enzyme is superior to another enzyme, using
enzyme kinetic parameters?
By using an equation like the michaelis menten equation to analyze the rate of catalysis.
Discuss the concept of cooperativity/allosterism as it pertains to the regulation of
an enzyme?
in cooperativity, substrate itself can serve as an allosteric activator
allosteric- regulation of an enzyme by binding an effector molecule at a site other than the enzyme’s active site
Describe the process one goes through to determine the structure of glycans
attached to an Asparagine residue
NMR or mass spectrometry is preceded by their purification using chromatographic methods
Describe the steps in creating a cDNA library from mouse tissue
Library is created by inserting cDNA
fragments into vectors and cloning .
1= isolation of the mouse mRNA
2= synthesis 1st strand of cDNA using reverse transcription
3= second strand of cDNA generation using Dna poly
4 Purify
5 incorporation of cDNA into a vector, insert recombinant vectors
6 screen colonies with pcr
Compare and contrast symport and antiport. Which term best describes the
transport system mediated by the SERCA pump? What type of ATPase is the SERCA
pump? What does it transport?
Both antiporters and symporters are used in secondary active transport
Antiports and symports are cortansport systems that transport 2 solutes across a membrane.
Anti= moves in opposite direction
Symp= move in same direction
SERCA pump is a uniporter for Ca2+ ions. It is a P type ATPase.
Describe the basic structure and function of P-type ATPases. What some
examples of these membrane proteins?
Pan - phosphorylation domain, actuator domain, nucleotide binding domain
Cation transporters, phosphorylated by ATP as part of transport cycle.
Examples: sodium potassium pump, proton potassium pump
The fatty acids that are present in phospholipids are variable in length and degree
of unsaturation. How does this variability effect membranes? How do sterols effect
membranes? Think in terms of melting points, order and disorder. Do cells use these
physical properties to modify the properties of membranes?
Changes in length and DOU changes order and disorder of lipid bilayer. The more cylidindrical the Michelle the more disordered. Sterols affect membrane by making rafts effecting membrane permeability.
