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BHS 150.1 – Biochemistry I
Notetaker: Irina Pukhovich
Date: 10/18/2012, 2nd hour
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Clicker Questions:
1. You are working in a research lab and discover a new protein in the lacrimal gland cell. It is a
transporter on the lumen side. It is important for transporting both K+ and Cl- into the duct of the
lacrimal gland. How would this protein transporter be classified?
a. Passive symport system
i. This is a hypothetical situation. Normally there are 2 channels on the lumen side.
One for K+ and one for Cl-. If it is a transporter instead---how would this
transporter be classified?—passive symport system
2. Chylomicrons contain which three (3) of the following substances?
a. Dietary triglycerides, dietary cholesterol, and dietary vitamins.
i. Chylomicrons consist of dietary things
3. Which bond is characteristic of the primary structure of a protein?
a. Peptide bond
4. To complete production of 2 myristic acid (14:0), the fatty acid synthase dimer complex needs:
a. 14 acetyl CoA, 24 NADPH’s, 6 cycles
5. The best antioxidant to prevent oxidation of collagen in the corneal stroma is:
a. Vitamin C
i. Stroma needs hydration- lots of water—vitamin C is water soluble
6. Cytosolic acetyl CoA comes from:
a. The mitochondria when citrate builds up
i. If Krebs cycle has enough energy, it slows down, citrate builds up, and acetyl
CoA can leave then. Regulatory step that is important..need to understand!!
7. How many moles of ATP are produced when one mole of glucose is completely oxidized to
carbon dioxide and water (assume the use of glycerol phosphate shuttle)?
a. 36
i. 38 is with the other shuttle.
8. The G protein alpha-subunit is an intracellular protein that
a. Binds GTP to activate effector enzyme
9. Stimulation of tears by the lacrimal gland cells requires:
a. Activation by IP3 –stimulated release of Ca++ from the SER and K+ and CL- channels
and DAG sensitive kinases to release proteins.
10. During metabolism, the conversion of acetyl CoA to malonyl CoA is the committed step of
a. Fatty acid synthesis
11. The process of Beta-Oxidation of one mole of myristic acid (C14) produces:
BHS 150.1 – Biochemistry I
Notetaker: Irina Pukhovich
Date: 10/18/2012, 2nd hour
Page2
a. 6 moles each of FADH2 and NADH, and 7 moles of acetyl Coa
i. That would be 30 ATP from Beta oxidation. From total oxidation, you would get
(7x12) +30-2= 112 ATP
12. The purpose of the pentose phosphate pathway is to
a. Produce NADPH and then recycle the carbons for the use by the glycolytic pathway
13. Which of the following is an example of a transporter that moves substances in opposite
directions using Na+ concentration gradient as the driving force?
a. The corneal endothelium Na+/H+ transporter
i. Moving Na+ out of the stroma and putting the H+ back in. driving for is the Na+
concentration gradient.
ii. Know and classify any transporter that we have looked at!!
14. In the cornea, the role of keratin sulfate found associated with collagen is to create:
a. More regularly spaced collagen fibrils with more similar diameters in the stroma.
i. Keratin sulfate and collagen is more with limiting the diameter, the other ones are
helping with the spacing. But they all work together.
15. Which one of the following is a consequence of deficient retinoic acid on the bulbar conjunctival
cells?
a. Not enough carbohydrates on the mucin
16. Which of the following aqueous layer tear substances acts as transporter of lipophilic substances
to the conjunctiva?
a. Lipocalin
17. The effects of a competitive inhibitor on the enzyme kinetics will be to:
a. Decrease the apparent affinity of the substrate for the enzyme.
i. (Review competitive vs non competitive )
18. The predominant corneal lactate dehydrogenase (LDH) is H1M3, which can do two (2) of the
following?
a. Converts lactate to pyruvate for a larger supply of energy, if O2 is available and converts
pyruvate to lactate to oxidize NADH to NAD+ when O2 is not available.
19. The role of the electron transport chain in the production of ATP is to:
a. Accept electrons from NADH and then pump protons from the matrix to the
intermembrane space.
20. Beta-oxidation in the cells is regulated by which two of the following mechanisms?
a. Increase levels of malonyl CoA inhibits transport of fatty acids into the mitochondria, and
its located in the mitochondria.