1. A reducing agent will accept electrons and an oxidizing agent will donate electrons.
a) True
b) False
Explanation: An oxidizing agent will absorb electrons and will therefore become reduced whereas a reducing agent donates electrons, becoming oxidized in the process.
2. Keq is greater than 1.0 depending on which of the following conditions?
a) standard free energy change is negative
b) standard free energy change is positive
c) chemical reaction proceeds in reverse direction
d) products are not formed
Explanation: When standard free energy change is negative value then Keq is greater than 1.0 and the formation of products is favoured.
3. Glycolysis can occur in ___________
a) aerobic cells
b) anaerobic cells
c) both aerobic and anaerobic cells
d) neither aerobic and anaerobic cells
Explanation: Glycolysis does not require the presence of oxygen and therefore can occur in both aerobic and anaerobic cells. In anaerobic cells glucose is degraded into fermentation products and in aerobic cells glucose is degraded into carbon dioxide and water.
4. The step where glyceraldehyde-3-phosphate is oxidized is substrate-level phosphorylation.
a) True
b) False
Explanation: The step where glyceraldehyde-3-phosphate is oxidized to 1,3-Biphosphoglycerate is oxidative-level phosphorylation where a pair of electrons (two hydrogen atoms) is removed.
5. Xylulose-5-phosphate is an intermediate in ___________
a) Glycolysis
b) Pentose Phosphate Pathway
c) Entner-Doudoroff Pathway
d) Fermentation
Explanation: Epimerization of ribulose-6-phosphate yields xylulose-5-phosphate and ribulose-5-phosphate in Pentose-phosphate pathway. These two compounds are the starting point for a series of transketolase and transaldolase reactions.
6. How many molecules of glucose-6-phosphate are regenerated in pentose-phosphate pathway?
a) 3
b) 2
c) 5
c) 4
Explanation: From 6 molecules of ribulose-5-phosphate, 5 molecules of glucose-6-phosphate are again regenerated.
7. Entner-Doudoroff pathway takes place only in procaryotes.
a) True
b) False
Explanation: Entner-Doudoroff pathway is found both in aerobic and anaerobic procaryotes, particularly among Gram-negative bacteria but not in eukaryotes.
8. Which of the following are propionic acid bacteria?
a) Streptococcus
b) Acetobacter
c) Clostridium
d) Veillonella
Explanation: Veillonella is a propionic acid bacteria that produce propionic acid, acetic acid and carbon dioxide as fermentation products.
9. What is the other name of glycolysis?
a) PPP cycle
b) TCA cycle
c) C4 cycle
d) EMP pathway
Explanation: EMP is named after the scientists that proposed the pathway, and they are Embden, Meyerhof, Parnas. It involves the conversion of glucose into pyruvic acid.
10. How many ATPs are paid back during the Pentose phosphate Pathway?
a) 1
b) 3
c) 4
d) 5
Explanation: One ATP is paid back for converting glucose into glucose-6-phosphate in the presence of hexokinase enzyme.