Muscle cells use a variety of fuel sources: fatty acids at rest and glucose during exertion, at least initially. Muscle cells also vary widely in their energy demands and use glycogen stores only for themselves, not sharing with other cells. Glycogen breakdown overly exceeds glycogen synthesis by 300-fold, and they do not respond to glucagon. Muscle cells also do not perform gluconeogenesis, fatty acid synthesis, or ketogenesis. On the other hand, liver cells are very important for fatty acid homeostasis, performing triacylglycerol formation and fatty acid synthesis. They are also the primary site of ketone body synthesis and directly regulate blood glucose levels in response to hormones. Liver cells are also important storage sites for glycogen with equal rates of synthesis and breakdown of glycogen. Like muscle cells, liver cells use a variety of fuel sources that change depending on conditions.
A plant called Arabidopsis thaliana was used to conduct three different experiments to explain how mesophyll conductance respond to the environment (Mizokami et al., 2017). One wildtype control called Col-0, two mutations, ost1 and slac1-2, were examined to eliminate factors that may influence the data not to represent an accurate display (Mizokami et al., 2017). Both of these mutants are insensitive to increase in the ABA and external CO2 levels because the stomata do not close properly. These mutations allowed Mizokami et al. to factor out the relationship between the stomatal conductance and the intercellular CO2 (2017). The data were collected and presented in multiple graphs and panels for different scenarios so that the readers could follow along the descriptions.
Immunology is largely based on the recognition and discrimination of self and non-self. Many pathogens have molecular signatures that allow the immune system to recognize and target them for destruction (Janeway Jr. et al. 2002). Unlike most pathogens, tumor cells lack these identifiable molecular signatures, allowing them to evade recognition as “non-self” and subsequently the immune response. Instead, cancer cells display tumor antigens that can be recognized by the immune system. Two such categories of these tumor antigens include tumor-associated antigens (TAAs) and tumor-specific neoantigens, which arise through different mechanisms. TAAs are expressed at low levels in normal tissues but are overexpressed in cancer cells, whereas tumor-specific neoantigens arise via non-synonymous mutations in the tumor itself (Lu et al. 2016). In some cases, these mutations lead to the expression of mutated peptides.
Metabolic pathways must be regulated to release energy when required, to store extra energy, and to synthesize molecules when needed. Specific reactions or enzymes in a mechanism serve as key regulatory steps, and usually they are those with largely negative changes in free energy. These are irreversible reactions that cannot be reversed through the manipulation of cellular conditions. If a chemical reaction in one direction is irreversible, then the opposing pathway must use a different chemical reaction and different regulatory enzyme. Different regulatory enzymes for opposing pathways allows for independent regulation based on cellular conditions, also known as fine-tuning. This is essential for regulating pathways. Regulatory enzymes are often as the beginning or end of a pathway, and the step that commits the pathway to a certain response is also highly regulated.
Lipids are a class of organic compounds that are fatty acids. These lipids are used for energy storage, membrane structure and signaling between organ systems. Lipids are also significantly nonpolar and most are mainly composed of hydrogren and carbon and able to form van der Waals interactions. Triacylglycerols are three fatty acids attached to a glycerol and are formed by dehydration reactions between glycerol hydroxyl groups and fatty acid carboxyl groups. Triacylglycerol are often found in the liver and adipocytes and are main tissues involved in fat metabolism. Material from the digestive system directly enters the liver and biosynthesis of lipoproteins occurs which is then distributed to body cells for energy use.
Researches had found that there are neurons that mirror emotions and pain experienced by others in the anterior cingulate cortex. The cingulate cortex contains mirror neurons which allows us to feel pain while seeing someone else in pain. Researchers tested this by making rats watch other rats being put under an unpleasant stimulus. When the cingulate cortex was looked at, researchers found that the observing rates had activated the same neurons as the rats who are receiving the unpleasant stimulus. Rats tend to freeze when they are in fear and a way to avoid being detected by predators. When researchers injected a drug that inhibited the activity of the cingulate cortex, it was found that the rats no long froze when they saw other rats receiving an unpleasant stimulus.
To get a basic idea of the Bradi3g27407.2 gene expression pattern, we used the e-FP browser. This web-based tool gave us a graphical summary of our gene expression data. We analyzed the pictogram, chart and table outputs and noted the tissues and organs where our gene is expressed. We explored more about our gene expression pattern using the PlaNet gene expression clustering program. In addition, we retrieved gene expression data from Phytozome for different Brachypodium distachyon plant growth conditions. We made figures for select conditions.
In an optometrist's exam room, one might find several pieces of equipment, all used to observe different parts of the eye. Commonly found in the examination room, is the phoropter, which is used to measure refractive error of the eye and helps to determine a patient's glasses and contacts perscription. Another common piece of equipment is a slit lamp, which is a microscope that allows light to enter the eye and the optometrist to view internal structures of the eye including the iris, lens and cornea. The tonometer is another tool that allows the optometrist to measure the pressure of the eye, used to detect glaucoma. It provides a more accurate measure of eye pressure, and is an alternative to the air-puff tonometer.
Chronic traumatic encephalopathy (CTE) is a degenerative brain disease that is linked to chronic head trauma, most commonly found in athletes. Since CTE affects the brain, signs and symptoms include changes in mood and behavior. The changes would lead to controlling problems, aggression, depression and paranoia. Researchers have found that the longer a person stays in high contact sports, the more prone they are to more dangerous effects of CTE. Currently there is no cure for CTE, the only prevention is to avoid repeated head injuries. People who are suffering with CTE would benefit from the care an Alzheimer's patient would receive.
In the unknown lab, we started by gram-staining our unknown organism. This is a way of testing for the presence of a thick polysaccharide wall. Gram positive organisms have this thick wall, while gram negative organisms do not. To gram stain, first 4-5 drops of crystal violet are added onto the organism. Then after 60 seconds it is washed off with sterile water, and 4-5 drops of iodine is added for 60 seconds. Then hydrogen peroxide is added and left on for 10 seconds. Then 4-5 drops of safran is added for 60 seconds. Once that is done, the organism is observed under a microscope. The gram positive organisms appear purple, and the gram negative organisms appear pink. Gram negative organisms consist of non-fermenters and enteric bacteria. Gram positive organisms consist of staphococci and strepococci. Oxidase tests are done on gram negative bacteria to distunguish between non-fermenters and enteric bacteria. Positive tests appear for non-fermenters. Catalase tests are done on gram positive tests to distinguisg between staphococci and strepococci. Positive tests appear for staphococci.