BIOCHEM exam2 known questions

1) Fructose in
solution can cyclize to
a. pyransose ring
b. furanose ring
c. both ring forms
d. none of the above

2) Which of the following monosaccharides isn’t
an aldose?
a. erythrose
b. fructose
c. glucose
d. glyceraldehyde
e. ribose

3) Maltose if composed of 2 molecules of
__________linked together by a _________­_
glycosidic bond.

a. glucose, β 1,4
b. glucose, α 1,4
c. glucose, α 1,6
d. glucose, β 1,6
e. galctose, β 1,2

4) A(n) _________ is a stereoisomer that is not a
mirror image around all the assymetric
carbon atoms.

a. epimer
b. anomer
c. diasteriomer
d. enantiomer
e. constitutional isomer

5) Glycosylation of proteins occurs at
the following site:

a. Cytoplasm
b. Nucleus
c. Golgi
d. Endoplasmic reticulum
e. Golgi & Endoplasmic Reticulum
f. Glycolsylation occurs outside the cell

6) When the carbohydrate protein is attached to a serine residue in a glycoprotein, it is referred to as a(n) _____ glycoprotein.

7) Which of the following is NOT a main function of lipids?

a. Cell Signalling
b. Fuel Source
c. Structural rigidity of the cytoskeleton
d. Membrane component
e. All of the above

8) _________ is a membrane lipid composed of sphingosine, fatty acid and a simple sugar.

9) Receptor protein for insulin has an extracellular binding region for insulin and an intracellular domain with enzymatic activity. This protein is an example of what kind of membrane protein?

10) The fluidity of the lipid side-chain in the
interior of a bilayer is generally increased by:

a. a decrease in temperature
b. an increase in fatty acyl chain links
c. an increase in the number of double bonds and fatty acids
d. an increase in the percentage of
phosphatidyl ethanolamines
e. the binding of water to the fatty
acyl side chains

11) Which of the following is NOT involved in
signal transduction through the epinephrine receptor?

a. ATP
b. cyclic AMP
c. cyclic GMP
d. GTP
e. All of the above are involved

12) Example of a mechanism for which a signaling
process might be purposely terminated:

a. change in temperature
b. aggregation of all protein subunits
c. protein dephosphorylization by phosphatases
d. all of the above
e. none of above

13) The type of transport which relies on the
driving energy of a gradient.

a. active
b. facilitative diffusion
c. simple diffusion
d. ATP mediated
e. both B and C

14) The low incidence of protein- or lipid-
flip-flop in a membrane preserves

a. membrane fluidity
b. membrane melting temperature
c. membrane asymmetry
d. all of the above
e. none of the above

15) _________ is the membrane protein that catalyzes the conversion of ATP to cAMP

16) The enzyme responsible for induction of
phosphoinositide cascade is:

a. Phospholipase A
b. Phospholipase C
c. Adenolate cyclase
d. Protein Kinase A
e. None of the above

17) Which of the following enzymes activates the
zymogen, Trypsinogen:

a. Enteropeptidase
b. Pepsinogen
c. Carboxypepsidase
d. Zymogenase
e. Aminopeptidase

18) Limit-dextrins are derived from starch after α–amylase treatment. The reason for the appearance of this partially digested material is ________ linkage.