1)Over the course of this experiment, our Broccolis have grown quite a bit especially within the past 6 months or so. Although they did have some difficulty striving for their lives, they overcame their struggles and were able to grow to their full potential. The main component that had tremendously helped our plants strive substantially was mitosis, also known as cell division.
Mitosis is a type of cell division in which one cell (the mother) divides to produce two new cells (the daughters) that are genetically identical to itself. In the context of the cell cycle, mitosis is the part of the division process in which the DNA of the cell's nucleus is split into two equal sets of chromosomes. The great majority of the cell divisions that happen in your body involve mitosis. During development and growth, mitosis populates an organism’s body with cells, and throughout an organism’s life, it replaces old, worn-out cells with new ones. For single-celled eukaryotes like yeast, mitotic divisions are actually a form of reproduction, adding new individuals to the population. In all of these cases, the “goal” of mitosis is to make sure that each daughter cell gets a perfect, full set of chromosomes. Cells with too few or too many chromosomes usually don’t function well: they may not survive, or they may even cause cancer. So, when cells undergo mitosis, they don’t just divide their DNA at random and toss it into piles for the two daughter cells. Instead, they split up their duplicated chromosomes in a carefully organized series of steps.
Additionally, miosis is a type of cellular division in which animals or plants multiply their cell numbers. Mitosis produces two identical daughter cells in each division. There are some differences between mitosis in plants and animals. Plants for example do not have centrioles and they don't change their shape before division like animal cells do. Mitosis in plants happens in the meristems of the plant that are located at the tip of the stems and roots. These two areas are responsible for production.
Plants perform photosynthesis because it generates the food and energy they need for growth and cellular respiration. It is important to note that not all plants photosynthesize. Some are parasites and simply attach themselves to other plants and feed from them. For plants to perform photosynthesis they require light energy from the sun, water and carbon dioxide. Water is absorbed from the soil into the cells of roots. The water passes from the root system to the xylem vessels in the stem until it reaches the leaves. Carbon dioxide is absorbed from the atmosphere through pores in the leaves called stomata. The leaves also contain chloroplasts which hold chlorophyll. The sun’s energy is captured by the chlorophyll.
Cellular respiration is a metabolic pathway that breaks down glucose and produces ATP. The stages of cellular respiration include glycolysis, pyruvate oxidation, the citric acid or Krebs cycle, and oxidative phosphorylation.During cellular respiration, a glucose molecule is gradually broken down into carbon dioxide and water. Along the way, some ATP is produced directly in the reactions that transform glucose. Much more ATP, however, is produced later in a process called oxidative phosphorylation. Oxidative phosphorylation is powered by the movement of electrons through the electron transport chain, a series of proteins embedded in the inner membrane of the mitochondrion. These electrons come originally from glucose and are shuttled to the electron transport chain by electron carriers. Cellular respiration is what cells do to break up sugars to give energy they can use. This happens in all forms of life. Cellular respiration takes in food and uses it to create ATP, a chemical which the cell uses for energy. More specifically, cellular respiration is the process of breaking down sugar to the form of energy. This happens in all forms of life. Cellular respiration is the process that uses food molecules taken in by a cell to create ATP, a chemical which the cell uses as an energy-rich molecule to power all kinds of cell activities.
Essentially, sugar (C6H12O6) is burned, or oxidized, down to CO2 and H2O, releasing energy (ATP) in the process. Why do cells need ATP? ALL cellular work -all the activities of life - requires energy, either from ATP or from related molecules. A lot of oxygen is required for this process! The sugar AND the oxygen are delivered to your cells via your bloodstream. This process occurs partially in the cytoplasm, and partially in the mitochondria. The mitochondria is another organelle in eukaryotic cells. like the chloroplast, the mitochondria has two lipid bilayers around it, and its own genome (indicating that it may be the result of endosymbiosis long ago). In some ways similar to the chloroplast, the mitochondria also has two main sites for the reactions: The matrix, a liquid part of the mitochondrion, and the cristae, the folded membranes in the mitochondrion. 1: Glycolysis ("splitting of sugar"): This step happens in the cytoplasm. One Glucose (C6H12O6) is broken down to 2 molecules of pyruvic acid. Results in the production of 2 ATPs for every glucose. But glucose is split into 2 molecules of pyruvate!). 2: Transition Reaction: Pyruvic Acid is shuttled into the mitochondria, where it is converted to a molecule called Acetyl CoA for further breakdown. 3: The Krebs Cycle, or Citric Acid Cycle: Occurs in the mitochondrial matrix, the liquid-y part of the mitochondria. In the presence of Oxygen gas (O2), all the hydrogens (H2) are stripped off the Acetyl CoA, two by two, to extract the electrons for making ATP, until there are no hydrogens left - and all that is left of the sugar is CO2 - a waste product - and H2O (exhale). The Krebs cycle results in the production of only ~4 ATPs, but produces a lot of NADH, which will go on to the next step. 4: The Electron Transport Chain and Chemiosmosis ("the big ATP payoff"). Occurs in the cristae of the mitochondria, the folded membranes inside the chloroplast. Electrons from Hydrogen are carried by NADH and passed down an electron transport chain to result in the production of ATP. Results in the production of ~32 ATPs for every glucose. The energy is used for a variety of reasons but mainly for growth.
2) The mechanism of transcription has parallels in that of DNA replication. As with DNA replication, partial unwinding of the double helix must occur before transcription can take place, and it is the RNA polymerase enzymes that catalyze this process. Unlike DNA replication, in which both strands are copied, only one strand is transcribed. The strand that contains the gene is called the sense strand, while the complementary strand is the antisense strand. The mRNA produced in transcription is a copy of the sense strand, but it is the antisense strand that is transcribed. Ribonucleotide triphosphate (NTPs) align along the antisense DNA strand, with Watson-Crick base pairing (A pairs with U). RNA polymerase joins the ribonucleotides together to form a pre-messenger RNA molecule that is complementary to a region of the antisense DNA strand. Transcription ends when the RNA polymerase enzyme reaches a triplet of bases that is read as a "stop" signal. The DNA molecule re-winds to re-form the double helix.
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