Biochemistry Test 4

Name:  _____________________                                                                                 May 2, 2017

Possible:  77 pts

1.   (2 pts)  If the amount of unsaturation in lipids increases, the fluidity of the lipids is expected to

a)  increase.               b)  stay the same.            c)  decrease.

2.   (9 pts) Sketch the structure of a phosphoglyceride containing stearate and oleate.  (Phosphoglycerides have a phosphate as the third group.)

2 pts:  glycerol

1 pts:  the ether linkage

1 pt:  18 carbons in stearate

1 pt:  18 carbons in oleate

1 pts:  double bonds at 9 position

1 pts:  double bonds cis

1 pt:  a phosphate is present

1        pt:  nothing extra

3.   (2 pts)  Is stearate or oleate an omega-3 fatty acid?

a)    Both are.              b)  Neither is.          c)  Only stearate is.         d)  Only oleate is.

4.   (3 pts)  A lipid bilayer is most likely to form if the lipid is

a)      a monoglyceride

b)      a diglyceride

c)      a triglyceride

d)      cholesterol

e)      a cholesterol ester

5.   (3 pts)  The process shown below is called _________________ diffusion.  transverse

 -2 pts for lateral

This Page:  19 pts


6.   (35 pts)  Sketch the glycolysis pathway, including structures, ATP, NADH, etc., and names of the first 5 enzymes.  (Names of structures do not need to be given.)

Description: F10_06

Description: F10_06

This Page:  35 pts


Description: C:\Documents and Settings\cking\My Documents\Biochemistry\Wikipedia\Glycolysis\glycolysis free energy changes.emf7.   (3 pts)  The figure to the right shows the free energy changes for each step of glycolysis.  Which steps in glycolysis are likely to be points where glycolysis is regulated?  (Give the step numbers.)

1, 3, and 10

8.   (2 pts)  Once formed in the cell, phosphoglucose does not diffuse out of the cell because phosphoglucose

a)    is formed in the mitochondria.

b)   is rapidly converted to citric acid.

c)    is charged.

d)   is rapidly dephosphorylated.

e)    gets trapped in the cell membrane.

9.   (2 pts)  In regards to phosphofructokinase in glycolysis, fructose-2, 6-bisphosphate is

a)      a positive effector

b)      a negative effector

c)      a substrate

10. (2 pts)  In regards to fructose bisphosphatase in gluconeogenesis, fructose-2, 6-bisphosphate is

a)      a positive effector

b)      a negative effector

c)      a substrate

-1 pt if backwards

11. (3 pts)  Below is the structure of NAD+.  Give the structure of NADH.

un-09-page285-1.jpg                                            00002B9CArt                            BB1CF510:

un-09-page285-1.jpg                                            00002B9CArt                            BB1CF510:

12. (3 pts)  During anaerobic metabolism, pyruvate is converted to lactate because

a)      lactic acid causes muscle cramps.

b)      bacteria require oxygen to produce alcohol.

c)      pyruvate cannot be converted to acetyl-CoA in the absence of oxygen.

d)      glucose builds up, which stops glycolysis.

e)      NADH has to be converted back to NAD+.

This Page:  15 pts

13. (4 pts)  ATP is formed in oxidative phosphorylation by an enzyme called ATPase.  What is the immediate source of energy that this enzyme uses to form ATP? ?

a)      ATP

b)      UTP

c)      GTP

d)      a proton gradient

e)      glucose

14. (4 pts)  In thermogenesis the uncoupler protein

a)      uncouples the proton gradient from production of ATP.

b)      absorbs heat to regulate body temperature.

c)      produces ATP and heat.

d)      produces heat from ATP.

e)      produces a proton gradient and heat.

This Page:  8 pts