BIOLOGY: Question and Answers - Biology Homework, University of XYZ

This document provides comprehensive answers to a series of Biology questions. The answers cover a wide range of topics, including the evolution of antibiotic resistance in bacteria, the structural differences between glycogen and cellulose and their implications, the formation and differences between glycosidic and peptide linkages, the structural differences and functions of triglycerides and phospholipids, the potential structure of a cell membrane with non-standard amino acids, the endosymbiotic theory and the presence of DNA in chloroplasts and mitochondria, the process of chromosome replication and the role of telomeres, the importance of base pairing rules in DNA structure and replication, the significance of complementary DNA strands, the advantages of controlled sugar breakdown over direct burning, and the role of activation energy barriers in endergonic reactions. The document offers detailed explanations and insights into these key biological concepts, making it a valuable resource for students studying Biology.

Running head: BIOLOGY
BIOLOGY QUESTION AND ANSWERS
Name of the Student
Name of the University
Author note

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Answer 1
 The common ancestor of modern superbugs was first discovered in the gut of land
animals
 Antibiotic resistance evolves bacteria through natural selection and mutation in
specific gene; leads the bacteria resist the antibiotic related action.
 As the generation time of bacteria is faster, the rate of molecular evolution of
bacteria is also higher.
Answer 2
 Glycogen and cellulose are made up of glucose monomers with alpha
configuration, whereas cellulose is made up of glucose monomers with beta
configuration.
 In Glycogen, two glucose monomers are linked together through alpha-1,4-
glycosidic bond, whereas in cellulose, these monomers are linked through beta-
1,4-glycosidic linkage.
 Due to the difference in the structure the human amylase enzyme is unable to
break the cellulose as humans lack beta amylase whereas, animals have beta
amylase therefore can consume cellulose.
Answer 3
 During polymer formation, two or more glucose molecules are linked through
glycosidic linkages, these glycosidic bonds can be of alpha or beta linkage in

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which, one glucose molecules OH-group is linked to another glucoses carboxyl
group.
 The prime difference is in the stereotype of glucose molecule.
 Peptide linkage is the bond in which, one amino group of one amino acid linked
to another amino acids carboxyl group.
 Both these bonds are susceptible to dehydration, as OH molecule plays an
important role in the formation of these linkages.
Answer 4
 Triglycerides contain three fatty acids head groups attached to the glycerol
backbone, whereas the phospholipids have two fatty acids as the head groups and
a phosphate group attached to the head of the fatty acid tails.
 As the phospholipids contain charged molecule at the head, it allows the lipid
inside to properly mix with water and fat, therefore made the cell membrane
structure, (containing hydrophilic and hydrophobic heads both).
Answer 5
 if there are no fluid-mosaic model and phospholipids and only amino acids are
available for the formation of cell membrane, a nonstandard amino acid can be
used in which, the R-group will generally have a long fatty acid chain.
 In this the amino and carboxyl group will determine the hydrophilic group of cell
membrane and the long fatty acid will determine the hydrophobic end of the
membrane.

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Answer 6
 Chloroplast and mitochondria possesses their own DNA for generation of protein
for their functioning because according to the endosymbiotic theory of evolution,
these two organelles are believed to be acquired from bacterial origin.
 When one organism lives inside another, it is called endosymbiosis and
mitochondria is supposed to inherit the remaining DNA of the endosymbiont
while cellular up taking. Therefore, other organelles did not possess DNA.
Answer 7
 before replication, the chromosome undergoes transcription so that both the cells
generated can be provided with similar DNA
 Each lagging strand, while replication (carried out by DNA replicase) has a short
RNA strand that leads to the formation of telomere at the tip of DNA, to prevent it
from coagulation, however the replication is incomplete as the ends are not
replicated.
 Telomerase is the enzyme that helps to replicate the end and adds bas eat the end,
however with every cell division the length gets shorter and the cell starts aging
and eventually causes cell death.
Answer 8
 If adenine had the ability to pair with all three DNA bases, the double helix
structure would be impossible to achieve as each base pair has their own angle at
which it helps the formation of double helix.

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 DNA replication would also been hampered as each base pair has their own
binding site in 30Sribosome that helps to attach specific bases on the DNA strand
while replication, hampering the proper replication of DNA.
Answer 9
 The two strands of DNA are complementary to each other that creates a similar
copy while transcription and a complimentary copy while replication.
 Further, there are endless number of sequences can be replicated through the four
base-pairs leading to unique and differentiable sequence for each individual
Answer 10
 Direct burning of sugar leads to use all the activation energy to generate free
energy, however all these energy cannot be stored.
 On the other hand, smaller steps requires less amount of activation energy and
through small and controlled processes generates free energy that are stored in
cells as NADH, ATP and NADPH). Therefore, slower breakdown is required.
Answer 11
 If there were no activation energy barrier for the generation of cellular
components through endergonic reaction, there would have been a tendency of
those end product to revert back to its initial state. Therefore, activation complex
would require more energy to initiate the reaction, but the reaction would never
attain stability.

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 The reason behind this is the higher energy productsthan the reactants of the
reaction due to the energy producing transition states. Hence, the reaction would
never be a spontaneous reaction.

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