Answer:
i) Glucose
ii) β(1-4) glycosidic bonds.
iii) Oxygen
Explanation:
Cellulose is an important structural carbohydrate found in plants. It forms a major component of the plant cell wall.
Cellulose is a polysaccharide formed by monomers of glucose. These glucose monomers are joined together by covalent bonds called β(1-4) glycosidic bonds, which means that the 1st carbon of one glucose is bound to the 4th carbon of the next glucose. To make this arrangement, every other glucose molecule in cellulose is inverted, which you can see in the diagram.
Glucose monomers contain carbon, hydrogen, and oxygen only. If you look at the pattern of the molecule (remembering every second glucose is inverted), you can see that Z must be O.
The functional group denoted by Z is oxygen. The OH groups on the glucose from one cellulose chain form hydrogen bonds with oxygen atoms on the same or on another chain, holding the chains firmly together and forming very strong molecules - giving cellulose its strength.
Answer:
Bacteriophages (phages) are viruses that infect only bacteria and do not infect mammalian or plant cells. Phages are ubiquitous in the environment. Phages or bacteriophages were chosen as a model system for their simplicity, as they only contained protein-coated nucleic acid. Alfred D. Hershey and Martha Chase (who were part of the bacteriophage group) in 1952 studying the infection of the bacterium Escherichia coli by the T2 phage show that the information definitely resides in the DNA. They used phage with either [32P] -labeled DNA or [35S] -labeled proteins to infect the bacteria. Immediately afterwards, they centrifuged the sample so that the infected bacteria remain in the pellet and the virus capsids (proteins) remain in the supernatant. [35S] is found in the supernatant, whereas [32P] is found in bacteria. After one cycle of infection, it was observed that when phage labeled in the [35S] proteins were used, only 1% of the radioactivity was incorporated into the progeny. But when phages were [32P] labeled, more than 30% of the radioactivity was in the progeny. They showed directly that what is transmitted from one progeny to another is the DNA and not the proteins, despite having first "diluted" in a bacterium.
Explanation:
Bacteriophages are viruses that infect bacteria in a specific way. Bacteriophages, like other known viruses, are found in an intermediate zone between living organisms and inert matter. Bacteriophages bind to the host pathogenic bacterium, introduce their genetic material, replicate inside it and destroy it. Hersey, along with his assistant Martha Chase, used phages because they knew that T2 phages were made up of 50% proteins and 50% nucleic acids and that phages entered bacteria and reproduced. As the progeny carried the same infection traits, the genetic material of this had to be transmitted to the offspring, but the mechanism was unknown. These scientists carried out an experimental work with the T2 virus, a bacteriophage that infects the bacterium Escherichia coli, which it reproduces by attaching itself to the outer wall of the bacterium, injecting its DNA into it where it replicates and directs the synthesis of the phage's own proteins. Phage DNA is encapsulated within proteins and produces phages, which lyse or disrupt the cell and release phage from progeny. They infected a culture of bacteria with radioactively labeled phages: the protein coat with sulfur (35S) and its DNA with phosphorus (32P). After infection, they separated the phages from the bacteria by violent shaking using a mixer (hence the name of the experiment). By centrifugation the much smaller phages remained in the supernatant and the much larger bacteria in the pellet. 85% of the radioactivity corresponding to DNA appeared in the pellet and 82% of the protein in the supernatant. This result supported the idea that DNA was the only component of the bacteriophage that penetrated the interior of the bacteria and, having the ability to form new phages, constituted the genetic material.
Answer:
In addition to biology, evidence drawn from many different disciplines, including chemistry, geology, and mathematics, supports models of the origin of life on Earth. In order to determine when the first forms of life likely formed, the rate of radioactive decay can be used to determine the age of the oldest rocks (see optional problems C and D, below) exposed on Earth’s surface. These are found to be approximately 3.5 billion years old. The age of rocks can be correlated to fossils of the earliest forms of life. A. The graph compares times of divergence from the last common ancestor based on the fossil record with a "molecular time" constructed by comparing sequences of conserved proteins to determine a mutation rate (after Hedges and Kumar, Trends in Genetics, 2003). Explain how such a molecular clock could be refined to infer time or the evolution of prokaryotes. B. Using a molecular clock constructed from 32 conserved proteins, Hedges and colleagues (Battistuzzi et al., BMC Evol. Biol. 2004) estimated the times during which key biological processes evolved. A diagram based on their work is shown. Connect the time of the origin of life inferred from this diagram with the age of the oldest fossil stromatolites and the age of the oldest exposed rock to show how evidence from different scientific disciplines provides support for the concept of evolution. Evaluate the legitimacy of claims drawn from these different disciplines (biology, geology, and mathematics) regarding the origin of life on Earth. The oldest known rocks are exposed at three locations: Greenland, Australia, and Swaziland. The following application of mathematical methods provides essential evidence of the minimum age of Earth.
Explanation:
The most important things for a cell<span> are oxygen in order to respire and Glucose, also for respiration. This is used in a process called glycolysis where the </span>cell<span> makes a chemical called ATP which is basically our energy
Hope this helped!</span>
A cell theory.
Since cells are the basic unit of structure in all organisms and also the basic unit of reproduction.
