Download Chapt 2

STUDY G UIDE—CHAPTER 2
Reading Assignment: Section 2.1-2.2, 2.4-2.6
Experimental Pathways: Chaperones
Human Perspective: Protein misfolding can have deadly consequences
Concepts:
Know the major chemical constitution of cells
What are the small organic molecules and how are they related to the four classes of
macromolecules?
What are the differences between covalent and non-covalent bonds? What are the characteristics
of non-covalent bonds, which are polar, non-polar?
What is the general structure of carbohydrates, what types of functions do carbohydrates serve in
the cell?
What are the important features of lipids? What are the major types? What is the general
structure of each? What use does the cell make of each type?
What is the general structure of proteins? Why are they able to carry out so many diverse
functions?
What are the major groups of amino acids and how do they differ? What is special about Cys,
Gly, Pro?
What are the levels of protein structure, what types of bonds are important in establishing each
structure? What determines the final structure of a protein? When a protein has finished
folding what types of amino acids tend to be on the outside? On the inside? Why?
What are motifs, how can we use them to tell us about protein function? What are the major
motifs?
In what general order do proteins fold?
What is the function of chaperones, what are their characteristics, where are they found?
What has gone wrong in people with Alzheimers, CJD?
What are the components of nucleic acids, how are they linked?
Terms:
Fat, Phospholipid, Steroid
α-Helix, β-pleated sheet
Motif, Domain
Native, Denatured
Chaperones, Chaperonin, molecular chaperone
Peptide bond, phosphodiester bond, hydrogen bond, ionic bond
Hydrophobic interaction, van der Waals force
Proteins:
Hsp60
Hsp70
Prion
Sample Questions:
Which of the amino acids described below has the most potential for forming ionic bonds:
1. polar, non-charged
2. polar, charged
3. nonpolar
4. glycine
5. proline
Hydrogen bonds can occur between which of the following molecules:
1. The sulfhydral in cysteine and the hydroxyl of serine
2. Two parts of the peptide backbone of a protein
3. The phosphodiester backbone of two strands of nucleic acid
4. The non-polar portions of two fatty acids
5. Both 2 and 4
Which of the following statements about chaperones is NOT true:
1. Chaperones bind covalently to a protein while it is folding.
2. Chaperones recognize hydrophobic portions of a newly synthesized proteins
3. Chaperones are found in prokaryotes and eukaryotes
4. Chaperones are present in mitochondria
5. There is more than one class of proteins that assist with folding
The structure that is formed when two subunits are held together by wrapping amphipathic alpha
helices around each other:
1. Helix-loop-helix
2. Zinc Finger
3. Coiled coil
4. α/β barrel
5. proline rich domain
The gene that is mutated in cystic fibrosis was positionally cloned and when sequenced the
normal gene (CFTR) was found to have several stretches of 20 hydrophobic amino acids. This
led researchers to conclude that:
1. The CFTR protein must typically exist as a denatured protein.
2. CFTR had no domains in common with any other proteins.
3. The CFTR protein must exist as a molten globule in the cytoplasm.
4. The CFTR protein must be found in the membrane.
5. No conclusions could be drawn.