Fill the following blanks with correct words:

(Questions 1-14).

Q1- Warburg and Christian described the oxidation of glucose-6-phosphate to …………… via ………………… . Q2-In phosphoketolase pathway the conversion of glucose to pentose sugars serves as a major source of the reduced ……….. that drives a myriad of biosynthetic reactions. Q3- Operation of the oxidative pentose phosphate cycle provides for the formation of two very important biosynthetic precursors, ………. and ……………, which serve as precursors to the ………….. amino acids . Q4- A major regulatory step in gluconeogenesis is ………. carboxykinase, encoded by pckA in E. coli. Q5- There are four different types of nucleotides found in DNA, differing only in the ………... Q6- The sugar-phosphate backbone is on the …………… of the DNA helix where the polar phosphate groups (red and yellow atoms) can interact with the polar environment. Q7- In glycolysis in muscle tissue and in lactic acid bacteria (Streptococcus, Lactococcus, Lactobacillus), …………….. is reduced to lactate. Q8- Meyerhof and others strongly asserted that the …………… of (EMP) pathway was the main route of ………… catabolism. Q9- Phosphoketolase pathway is not essential for the growth of ………….. Q10- Operation of the oxidative pentose phosphate cycle provides for the formation of two very important biosynthetic precursors, ………….. and …………, which serve as precursors to the …………… amino acids . Q11- In gluconeogenesis the PEP carboxykinase, encoded by pckA in E. coli. is regulated by …………….. repression, a process in which gluconeogenesis is inhibited when glucose or other carbohydrate carbon sources are available. Q12- Purines,adenine and ……………… are the larger of the two types of bases found in DNA. Q13- A nucleoside is one of the four DNA bases covalently attached to the C1' position of a ……. 14- In glycolysis in muscle tissue and in lactic acid bacteria (Streptococcus, Lactococcus, Lactobacillus), pyruvate is reduced to ………….

Answer the following sentences by T or F, and correct the underlined word(s) of false ones: (Questions 15-34 ). Q15- The cell wall of gram-positive cells is composed of multiple layers of aminoglycosides . Q16-The ribosome contains two subunits, 30S and 50S, each composed of special ribosomal lipids and ribosomal ribonucleic acids (rRNA). Q17- A part of the tRNA molecule called the anticodon will base-pair with the codon in rRNA. Q18- Our paradigm cell (the gram-negative cell E. coli ) can reproduce in a minimal glucose medium once every 20 minutes. Q19- Carbohydrate metabolism is the progressive reduction of a sugar in which hydrogens are transferred from intermediates in the pathway to hydrogen-accepting molecules. Q20- The assimilation of N involves the amidation of one of the 13 key metabolites, αketoglutarate, to form glutamic acid. Q21- Some of the oxidation–reduction enzymes interact with molecular oxygen to give rise to superoxide (•O2−), hydroxyl radicals (OH•), and hydrogen peroxide (H2O2), all of which are extremely toxic. Q22- Carbohydrates are not the only compounds utilized as sources of energy by microorganisms. Q23- In yeast, pyruvate (final product of EMP pathway) is cleaved to acetaldehyde and carbon dioxide. The acetaldehyde is then reduced to ethanol by alcohol dehydrogenase. Q24- E. coli utilizes gluconate via the Entner-Doudoroff pathway. Gluconate dehydratase activity is virtually absent in cells grown on glucose and is induced only by gluconate. Q25- The surface of gram-negative cells is much more complex than that of grampositive cells. Q26- The cell wall of gram-positive cells is composed of multiple layers of aminoglycosides. Q27- The ribosome translates mRNA into protein by reading three nucleotides (known as a triplet codon) as a specific amino acid.

Q28- In feedback inhibition, the synthesis of an enzyme already present in the cell is inhibited by the end product of the reaction. Q29- The most universal energy transfer compound found in living cells is ATP. Q30- Some microorganisms such as E.coli can fix atmospheric nitrogen via nitrogenase to form ammonia (NH4 +) and then assimilate the ammonia into amino acids. Q31- Aerobic organisms possess cytochromes and cytochrome oxidase, which are involved in the process of oxidative phosphorylation. Q32- The EMP pathway is common to a great many microorganisms but not in higher forms. Q33- The enzyme fructose bisphosphate (FPB) aldolase is one of the most critical steps in the pathway. Q34- Z. mobilis is unique in that it is the only genus known to utilize the EntnerDoudoroff pathway aerobically. Q35- Enumerate features of the DNA double helix? Q36- Write about bacterial nucleoid? Q37-What are the three major enzymatic reactions involved in glycolysis, that are insufficiently reversible to allow carbon flow from pyruvate in the direction of hexose synthesis. Mention the type of reaction catalyzed by each one of the following metabolism enzymes? Q38- Phosphorylase. Q39- Hexokinase. Q40- Phosphofructokinase (pfkA). Q41-Triose phosphate isomerase (tpi ). Q42- Phosphoglycerokinase (pgk). Q43- Enolase (eno). Q44- Pyruvate carboxylase. Q45- Fructose-1,6-bisphosphatase. Q46- ATP-glucose pyrophosphorylase.

Q47- Glycerophosphate dehydrogenase. Q48- Glycerol kinase. Q49-Pyruvate kinase. Q50- Enumerate features of the 5'-d(CGAAT) structure of DNA Q51- Write about visualization and composition of nucleoid? Q52- What are the steps and main enzymes of oxidative pentose phosphate pathway? Q53- Give a labeled draw of schematic representation of a typical (E. coli ) bacterial cell? Q54- What are functions of the interface between the microbial cell and its external environment? Q55-What are the composition of the cell surface of gram positive bacteria? Q56- Elucidate the steps of transcription in prokaryotes? Q57- What is the feed back inhibition? Explain its role in controlling of bacterial growth? Q58- Define the oxidative phosphorylation? Support your answer with two examples? Q59- An important mission of carbohydrate metabolism is the production of energy. Discuss that? Q60-Define the substrate-level phosphorylation? Support your answer with two examples? Q61-Define capsules in bacteria and write about its function and structure? Q62- What is the role of ribosomes in living cells? Q63- What are endospores? Elucidate their structures and functions? Q64- Explain the structure and role of peptidoglycan of the cell wall in gram positive bacteria? Q65- Write about organs of locomotion in microorganisms?

Q66- Explain with examples the nitrogen assimilation in microorganisms? Q67- What are the composition of the cell surface of gram negative bacteria? Q68- Define the growth and numerate the processes involving in it? Q69-What is the continuous culture?Write about it? Q70- Explain factor affecting growth? Q71- Write about the organotrophs? Q72- Mention the role of oxygen in microbial growth? Classify organisms according the their needs to oxygen? Q73- Write about the role of carbon dioxide in microbial growth? Q74- Define extremophiles? Write about two examples of them? Q75- Elucidate the steps of translation in prokaryotes? Q76-Write about proton motive force? Explain its role in energy production in microorganisms? Q77- write about the role of DNA polymerase in DNA replication in microorganisms? Q78- Enumerate the major chemical compositions of microorganisms? Q79- Define nicotinamide adenine dinucleotide (NAD)? Discuss its role in oxidation–reduction reactions? Q80- What is the genetic repression? Explain its role in controlling of bacterial growth?