Question

Discuss the relative advantages and disadvantages of light and electron microscopy. How would you best visualize (a) a living cell, (b) a yeast mitochondrion, (c) a bacterium, and (d) a microtubule? Identify which of the following statements are FALSE and then explain WHY they are false. (a) The hereditary information of a cell is passed on by its proteins. (b) Bacterial DNA is found in the cytosol. (c) All cells of the same organism have the same number of chromosomes (with the exception of egg & sperm cells). (d) The cytosol contains membrane-enclosed organelles, such as lysosomes. (e) Nuclei, mitochondria and peroxisomes are surrounded by a double membrane. (f) Protozoans are complex organisms with a set of specialized cells that form tissues, such as flagella, mouthparts, stinging darts, and leg-like appendages. (g) lysosomes, peroxisomes and golgi are sites of degradation for various cellular material What are the arguments that all living cells evolved from a common ancestor cell? Imagine the early days of evolution of life on Earth. Would you assume that the primordial ancestor cell was the first and only cell to form? Why/why not? (1-19) What is meant by the" polarity of a polypeptide chain" vs the "polarity of a chemical bond"? How do the meanings differ? Include diagrams to help explain your answer, (slightly enhanced 2-7) Phospholipids and fatty acids are said to be amphipathic. What is meant by this term, and how would an amphipathic molecule behave in water. Draw a diagram to help illustrate your answer. (2-20) The phosphoanhydride bond that links the last phosphate group in ATP is a high-energy linkage with a standard delta G value of -7 -3 kcal/mol. Yet in the cell, hydrolysis of this bond liberates from 11 to 13 kcal/mole of usable energy, (a) How can this be? (b) Why is there a range of energies given, rather than a precise number as for the standard delta G ? (3-8) Consider the effects of the following 2 proposed enzyme. The first enzyme (A) catalyzes the following reaction: ATP + GDP doubleheadarrow ADP + GTP and, the second enzyme (B) catalyzes the reaction: NADH + NADP + doubleheadarrow NAD+ + NADPH (a) State whether enzyme (A) would be beneficial or to cells and explain why. (b) whether enzyme (B) would be beneficial or to cells and explain why.

Answer 1

Due to connection imposed by the function in which variant types of microscopes provide images, various microscopes can be used in perfect ways that others cannot. For instance, it is not possible to comply with peculiar molecules permit a Light microscope or to look for lively processes occur using an electron microscope.
Light microscopes Advantages
• Low to procurement and perform
• Little and simplify
• Simple tendency of the specimen can be empirical
•Living as well as repetitious material can be looked on
• Preparation is usually quick and natural, requiring little mastery • Undeceptive by magnetic fields  
Disadvantages
•   Magnifies objects up to 1500x
•   Preparation may crumple specimen
•   The magnitude of the area is debarring
•   Has a conclusiveness power for systematic specimens of close by 1nm
Electron microscope
Advantages
•   The principal benefit is its effectual magnification.
•   The capability runs the series of scientific fields in addition biology, gemology, therapeutic and forensic sciences, metallurgy and nanotechnologies
. •   EMs including have novel technological and assets applications, such as semiconductor monitor, computer chip producing, ambience control and can impassive be used as part of a performance line.
Disadvantages
•   The evident disadvantages are cost, size, preservation, researcher credentials and image artifacts following from specimen preparation.
•   This type of microscope is a broad, bulky, at great cost piece of contraption, extraordinarily discerning to drumming and covering magnetic fields.
•   It needs to be kept in a field large enough to contain the microscope as well as defence and keep away from any unexpected manners on the electrons.
• Preservation involves living confident voltage supplies, currents to electromagnetic coils/lens and spread of cool water so the samples are not disabled or disturbed from warmth disposed off by way of the function of intoxicating the electrons. .