BIO303 Midterm Solved Past Papers

bio303

What is ncRNAs? (5)

Answer: • Large & Small Noncoding Regulatory RNAs

• One of the most exciting discoveries in the last decade of eukaryotic regulatory biology has been the identification and characterization of regulatory nonprotein coding RNAs (ncRNAs).
• NcRNAs exist in two general size classes,
• small consisting of microRNA (miRNAs) and silencing (siRNAs)

and

• Large consisting of long noncoding RNAs (lncRNAs)
• The small ncRNAs termed microRNA (miRNAs) and silencing (siRNAs) typically inhibit gene expression at the level of specific protein production by
• targeting mRNAs through one of several distinct mechanisms.
• Both siRNAs and miRNAs typically hybridize, via the formation of RNA–RNA hybridization to their targeted mRNAs

How industrial product are formed...asa e kch tha exact yd ni (5)

What is cori cycle? (3)

Answer: The pathway through which lactate produced by anaerobic glycolysis in skeletal muscle returns to the liver and is converted to glucose, which moves back to muscle ans is converted to glycogen is called cori cycle. Site: Liver Substrate: Lactate “occurs due to absence of glucose-6-phosphate in liver”.

how does ATP synthase work in inner mitochondrial? (2)

Answer: Electrones carried by NADH and FADH2 are funneled into a chain of mitochondrial (or in bacteria, plasma membrane-bound) electron carries the respiratory chainultimately reducing O2 to H2O. This electron flow drives the production ofATP.

three steps of breakdown of indutrial product?

Answer: Any industrial fermentation operation can be broken down into three main stages, viz,

1. Upstream processing,

2. The fermentation process

3. Downstream processing

what is transketolase?

Answer: • Transketolase catalyzes the transfer of a two carbon fragment from a ketose donor to an aldose acceptor In its first appearance in the pentose phosphate pathway, transketolase transfers C-1 and C-2 of xylulose 5-phosphate to ribose 5-phosphate, forming the sevencarbon product sedoheptulose 7-phosphate.

bio303

1) Vo is expressed_____volume (total), initial, final, all of these

2) Study of fermentation is called____(fermentology)

3) If K.eq is_____, dalta GO is positive(less than 1.0)

4. When the products of a reaction are less complex and more disordered than the reactants, the reaction is said to proceed with a _____(gain in entropy),change in enthalpy, increasing order,decreasing order

5) RNAis a polymer of (ribonucleotides)

6. RNA molecule is a single strand _____to only one of the two strands of a gene(complementary)

7) Is essentially expensive but essential glycolysis,(gluconeogensis),krebs cycle, PPP)

8) gluconeogensis and glycolysis shared.... Reversible steps___1,(3),5,7

9. in surface technique which of the following are used____gas, liquid, solid,( both liquid and solid)

10) The reaction catalysed by DNA photolyase is an example of.. (Free-radical reactions)

11) In biochemistry and pharmacology, a ligand meant by_____(binding)

12. Arthur Harden and William Young tested their hypothesis on_____enzymes, products, substrate, (all)

13) Lipases hydrolyzing enzymes of_____ (Lipid)

14) IUB Classification of Enzymes Aldolases are ____(aldehyde)

15) NAD and NADH are differ due to____ (phosphate)

16. oxidation reduction reaction Loss or gain of _______(electron), proton, electron and proton, proton

17) Define 1st law of thermopdynamics(2)

Answer: The first law is the principle of the conservation of energy: it states that “for any physical or chemical change, the total amount of energy in the universe remains constant; energy may change form or it may be transported from one region to another, but it cannot be created or destroyed.”

18) Write two ketone bodies in cell body(2)

•  Acetone
•  Acetoacetate

19) Write 5th step of glycolysis and name of enzymes(3)

Answer: Step 1: The first step in glycolysis is phosphorylation of glucose at the hydroxyl group on C-6 by a family of enzymes called hexokinases to form glucose-6-phosphate (G6P) Step 2: The G6P is again phosphorylated in D-fructose 6-phosphate. This time at C-1 to yield Dfructose 1,6-biphosphate (Step 3) For both phosphorylation, ATP is the phosphoryl group doner. Fructose 1,6-biphosphate is split to yield two three-carbon molecules, dihydroxyacetone, phosphate and glyceraldehydes 3phosphate (step 4); this is the lysis step that gives the pathway its name. The dihydroxyacetone phosphate is isomerized to a second molecule of glyceraldehydes 3-phosphate (step 5)

20) What are lyases? Give example(3)

Answer: Answer mentioned

21) Difference between DNA and RNA 5 steps?(5)

Answer: Answer mentioned

22) What are thioesters?(5)

•  In theoesters a sulfer atom is replaced the usual oxygen in the ester bond.
•  Theoesters have large, negative standered free energy change of hydrolysis.
•  Acetyle coenzyme A is one of many theoesters important in metabolism and has a large, negative, standard free energy of hydrolysis.
•  The acetyle group in these compounds is activated for trans-acylation, condensation or oxidation-reduction reactions.
•  Hydrolysis of the ester bond generates a carboxylic acid which can ionize and assume several resonance forms. 31.4 kj mol G for acetyle-CoA hydrolysis.

Bio303

2-july-2018 ....10:30am

Qno.1.write the phenomenon of phosphoryl group transfer by example of phosphocreatine(pcr).(5)

Answer: In the phosphocreatine the P-N bond can be hydrolysed to generate free creatine and Pi. The release of pi and the resonance stabilization of cretine favour the forward reaction. Pi is also resonance stabilized. The standard free energy change of phosphocreatine is large and negative 49,3 kj mol G