Anatomy & Physiology M and W 6:15–9:15 pm Introduction Many chemical reactions take place in each individual human cell, all performing the necessary functions for such a large, complex, multicellular organism. How do these reactions occur? Chemical reactions involve the breaking and reforming of chemical bonds between molecules (substrates), which are transformed into different molecules (products). Enzymes are biological catalysts. They help to increase the rate of chemical reactions.
Glycolysis is the breakdown of glucose. In celluar respiration, it is used to break down glucose into pyruvate. It occurs in the cytoplasm of the cell. ATP is used to split glucose into three-carbon pyruvate, producing 4 ATP and NADH 5.What is the difference between glucose, pyruvate, G3P, & acetyl?CoA? Glucose is what pyruvate and G3P come from.
Third, the substrate becomes activated through the enzyme-substrate complex, allowing the electrons and atoms to rearrange to form the product of the reaction. Fourth, the complex separates, releasing the product and enzyme independent of one another. Only the substrate is modified in the reaction, thus after being released enzymes may perform the same process. Each enzyme is specialized for a particular reaction, therefore many similar as well as different types of enzymes may be necessary for cell metabolism (McMurray, 1977). The four types of macromolecules that make up an organism’s diet are lipids, nucleic acids, proteins, and carbohydrates.
These are then oxidized in the mitochondrion’s matrix. Once the pyruvate is oxidized, it becomes Acetyl CoA, which then enters the Citric Acid Cycle. In the Citric Acid Cycle, the breakdown of glucose is carried out and turned into carbon dioxide. Glucose is broken down into carbon dioxide and water. For every glucose molecule broken
Next to the active site, but still a great distance away is the Allosteric site, sites containing receptors. The allosteric site is a part of enzyme activation, ‘the difference between the energy level of the transition state and the potential energy of reacting molecules.’ Another part of the enzyme activation is the activator, which links itself to the allosteric site; it changes the shape of the enzyme letting the active site to allow the substrate to latch on. Many cells can produce hydrogen peroxide as a toxic; this takes place by products from their own metabolic reaction. Another product cells can produce is catalase enzyme which helps breakdown hydrogen peroxide into water and O2 gas. Catalase enzyme 2 Hydrogen peroxide 2 water + oxygen + heat energy Every type of animal on Earth uses catalase in their organs, but it is commonly known that liver has the highest concentration.
The activity site in a metabolic reaction depends on the types of amino acids present, which determine the shape of the enzyme. Metabolic reactions in lipids and amino acids tend to produce a byproduct of hydrogen peroxide, which is toxic. The enzyme that breaks down hydrogen peroxide is called catalase, which metabolizes lipids and amino acids in living organisms. We set out to determine the effects of pH levels on the ability of the enzyme catalase to break down the byproduct of hydrogen peroxide. pH levels can have an effect on the shape of the protein molecule and when the shape of the enzyme is changed, the ability to catalyze the reaction is taken away.
Therefore, different centrifugal forces and times are used, specific to which organelle or cellular component you are trying to isolate. Mitochondria play a very important role in the cell since they generate most of the cell’s supply of ATP by the phosphorylation of ADP to ATP. This process involves a number of chemical reactions which together are referred to as cellular respiration. The first step is glycolysis which produces pyruvate and NADH from glucose. The pyruvate is then transferred to the mitochondria where they are converted into acetyl-coenzyme A. at this point the acetyl-coenzyme A enters the Krebs Cycle where it forms a series of intermediates.
These can then be transported in the appropriate form to the cells in the body through the circulatory system. For growth and repair of our cells and tissues energy is required, this is due to the biochemical reactions which build large molecules from simpler ones to occur. This energy is then needed in order to build proteins from amino acids, these are formed through the process of Active transport of substances in or out of our cells happens through this energy made, an example of this would be the transport of amino acids from the small intestine into the blood stream. Active transport often takes place against a diffusion gradient which then allows the body to control its internal environment more efficiently. When we move our body uses energy, this occurs on several levels: • inside our cells – chromosome • whole cells – sperm swimming • tissues – muscles contracting • whole organs – heart beating • part or whole organisms – walking Since the blood found in the human body is warm energy is used in order to maintain the temperature, we use 70% of this energy from respiration to do so and this makes sure the temperature stays at 37
Adenosine triphosphate is the energy storage molecule made using energy released during respiration and subsequently broken down into adenosine diphosphate and phosphate so that its stored energy is released to allow activities in cells to be performed. The reaction is summarized as follows: adenosine diphosphate+phosphate+energy⇌adenosine triphosphate | Both aerobic respiration and anaerobic respiration begin with glycolysis in the cytoplasm. During glycolysis the substrate glucose is split into two pyruvate molecules. Enough energy is released to make 4 ATP molecules, but 2 ATP molecules are used so that the net gain is 2 ATP molecules per glucose molecule. Then if oxygen is available both animal and plant cells carry out aerobic respiration in the mitochondria of the cells.
Reduction is a decrease in positive valence or an increase in negative valence by the gaining of electrons. Glycolysis is the process of breaking down glucose. Glycolysis takes place in the cytosol or cytoplasm in the cell. The energy from glycolysis powers all the systems that maintain homeostasis. Energy investment is the first phase of glycolysis where two ATPs are converted to 2 ADP molecules.