Tutor profile: Savanah T.
Write a good introductory paragraph for an essay. Any topic will do, but make sure it follows the typical reverse pyramid structure for introductory paragraphs. Include a thesis at the end.
Dogs are a common staple across the board for work animals. Used in the police force, fire force, and in the service capacity, dogs are capable of being reliable helpers to those in need. In the service industry, the dogs are trained in a variety of ways to assist disabled people in their daily life. For a blind person, one such canine may guide their owner to work or through unknown terrain, while the service dog for a human with seizure inducing medical problems may alert when a seizure in oncoming, catch the person when they fall, and find help. The training for these tasks is complex and rigorous, begun from an early age. Puppies chosen for a life in service must be intelligent, patient, and gentle in personality in order to best learn and assist throughout their life.
Explain the structure of H2O. Include bonds, types of bonds, and why those bonds occur.
H2O is a molecule made up of 2 hydrogens and one oxygen. The oxygen by itself has 6 electrons in its valence shell, while the hydrogens have 1 each. The hydrogens have an S orbital for a valence shell, while the oxygen has two S and one P orbitals. Both hydrogen and oxygen atoms are naturally going to interact with other atoms in a way that leads to greater stability, meaning they both will interact in ways that fill up their incomplete orbitals. For hydrogen, because is only has an S orbital to fill, it needs two total electrons to fill its valence shell. It has one, so it will interact to acquire another. Oxygen atoms have 6 electrons in a shell that will hold 8, so it seeks to have two more electrons. This mutual need for more electrons ensures that when O comes into contact with two H atoms, the O and H atoms will form a covalent bond, which means that one electron from each atom will be shared. Each bonds then counts as having two electrons. So, the H atoms now have two electrons each, while the O atom has gained 2 electrons from the two bonds it forms with the two H atoms. Now, all the atoms have a full valence shell, which means they are most stable. However, this bond is not equal. The O atom is more electronegative than the H atoms, so it has a stronger attraction to the shared electrons in the bond. This means that although the bond shares the electrons, the electrons spend much more time on the O atom's side of the bond. Electrons are negatively charged, so this gives the O atom a negative charge and the H atom a positive charge. When this difference of charges occur, the bond is referred to as a polar bond. So, H2O is made of 2 H and one O atom in a polar covalent bond.
How does the cell create proteins?
In the nucleus, the cell reads the DNA and produces mRNA strands which leave the nucleus and go into the cytoplasm of the cell. There, ribosome sub units come together to create the ribosome, which reads the RNA strand and produces a chain of amino acids. The primary structure of the protein is the order the amino acids are in. the secondary structure of the protein is when the amino acids interact with one another to form either an alpha helix- like DNA- or a beta sheet. The tertiary structure is these beta sheets or alpha helices interacting to form larger 3D structures all wrapped up with interactions once again between the amino acids. the quaternary structure is the last level of organization of a protein. Amino acids are made up of a back bone- consisting of a N-terminus and C- terminus- and a side chain or R group. The backbone of every amino acid is the same, the only differences occur in the R group. These differences- like charges or S atoms (which make disulfide bonds) are responsible for the differing structure- and therefore differing function of each protein. Basically, at a highschool biology level, the cell reads the DNA, transcribes it into RNA, sends the RNA to ribosomes outside the nucleus, and finally translates into amino acids, which form different proteins due to the difference in the arrangements of the amino acids' side chains.
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