Micro 2124 - EXAM I - Summer 1991

Part 1 - Multiple Choice (worth 3 points each). Please read each statement carefully and choose the best answer by writing the appropriate letter in the left margin.

1. The carrier used in the biosynthesis of fatty acids is:
a. tRNA
b. acyl carrier protein
c. flavoprotein
d. nucleoside diphosphate.

2. When E. coli are moving away from an agent which is chemotactic for them they tend to:
a. swim faster
b. swim slower
c. undergo catabolite repressi
on
d. tumble frequently.

3. What type of bacteria would tend to reduce highly oxidized inorganic compounds?
a. those that undergo anaerobic respiration
b. fermenters
c. Gram positives
d. phototrophs.

4. Chemotrophy and phototrophy refer to:
a. temperature requirements for growth
b. the structure of bacterial spores
c. differences in carbon sources
d. differences in energy sources.

5. The peptidoglycan of a bacterium:
a. is located primarily in the spore
b. is formed in the capsule
c. contains short peptides
d. is found only in Gram positive bacteria.

6. A governing principle of anaerobic respiration is that:
a. ATP is not produced
b. oxygen is not used as the terminal electron acceptor
c. only fats are used as substrates
d. alcohol is produced.

7. Procaryotes differ from eucaryotes because they:
a. do not have transfer RNA
b. do not have cytoskeletal elements
c. do not have unit membrane
d. do not have ribosomes.

8. Electron transport leads to:
a. substrate level phosphorylation
b. the creation of high energy bonds
c. increased gyrase activity
d. the extracellular transport of protons.

9. Most of the energy derived from the TCA cycle comes from:
a. substrate level phosphorylation
b. fermentation
c. GTP
d. electron transport.

10. The photosynthetic apparatus usually involves a reaction center, electron transport and:
a. the antenna
b. microtubules
c. photosynthetic vacuoles
d. the electron sink.

11. Enzymes which convert protonmotive force into ATP are called:
a. phosphatases
b. proteases
c. ATPases
d. catalases

12. Which of the following is not true about the outer membrane of Gram negative bacteria?
a. it is a lipid bilayer
b. it contains teichoic acids
c. it contains lipopolysaccaride
d. it forms the outer layer of the periplasm.

13. Chlorosomes are internal structures of bacteria which:
a. control elevation in liquids
b. are involved in photosynthesis
c. are the site of C02 fixation
d. orient bacteria in a magnetic field.

14. (A) substance(s) found in procaryotes but not in eucaryotes include(s):
a. polyhydroxybutyrate
b. tRNA
c. steroids
d. cytochromes.

15. Photosystem II is required in addition to photosystem I for photosynthesis if:
a. water serves as the source of electrons
b. the organism has no thylakoid membranes
c. light in the UV range is absorbed
d. carotenoids are used instead of chlorophylls.

16. The Calvin-Benson cycle is used by autotrophs to:
a. utilize reduced inorganics as an energy source
b. convert NAD to NADH
c. harvest light for transfer to reaction centers
d. utilize C02 as a carbon source.

17. The pentose phosphate cycle is important because it leads to the production of 5 carbon sugars and:
a. ATP
b. amino acids
c. NADPH
d. phospholipids.

18. The cell membranes of most procaryotes contain:
a. permeases
b. biosynthetic enzymes
c. esterified fatty acids
d. all of the above.

19. The primary difference between organelles in eucaryotes and organelles in procaryotes is the presence or absence of:
a. DNA
b.peptidoglycan
c. unit membrane
d. glycoproteins.

20. The tertiary structure of a protein is determined by:
a. binding to other proteins
b. interactions between amino acids in close proximity
c. interactions between widely separated amino acids
d. tautomeric shifts.

21. Introns are portions of:
a. DNA which do not code for protein
b. proteins which have no apparent function
c. receptors found in cell membranes
d. microtubules which are bound to the nuclear membrane.

22. Eucaryotes include:
a. fungi and bacteria
b. plants and blue-green algae
c. bacteria, protozoa and fungi
d. fungi, protozoa, plants and animals.

23. Another name for glycolysis is:
a. the Entner-Doudoroff pathway
b. the Embden-Myerhoff pathway
c. the citric acid cycle
d. gluconeogenesis.

24. Specialized proteins which bind to DNA and regulate its conformation are called:
a. histones
b. nucleons
c. regulons
d. helicons.

25. A nucleotide consists of:
a. a purine or pyrimidine base only
b. a base plus ribose or deoxyribose
c. a base plus ribose or deoxyribose plus a phosphate ion
d. none of the above.

Part II - Short Essay (worth 5 points each). Please answer the following questions completely but concisely.
1. Compare eucaryotic and procaryotic chromosomes (structure, number, histones and replication).

2. Define the following: chemoautotroph, chemoorganotroph, fermentation, substrate level phosphorylation and electron transport.

3. Compare the cell wall structure (everything outside of the cell membrane) of Gram positive and Gram negative bacteria.

4. List and describe each of the three main steps which occur during translation.

5. Draw a simple diagram showing how energy from sunlight can ultimately be converted into ATP in a chemoorganotroph. (Hint: Include at least one other group of procaryotes in the diagram.)