Kreb Biology Lab

There are two types of cellular respiration, aerobic and anaerobic. Aerobic respiration occurs when there is oxygen present and in the mitochondria (in eukaryotic cells) and the cytoplasm (in prokaryotic cells). Aerobic respiration requires oxygen; it proceeds through the Krebs cycle. The Krebs cycle is a cycle of producing carbon dioxide and water as waste products, and converting ADP to thirty-four ATPs. Anaerobic respiration is known as a process called fermentation. It occurs in the cytoplasm and molecules do not enter the mitochondria for further breakdown. This process helps to produce alcohol in yeast and plants, and lactate in animals. Only two ATPs are produced through this process. In yeast fermentation is used to make beer, wine, and whiskey.

Purpose: What is the purpose of this exercise? Are there any safety concerns associated with this exercise? If so, list what they are and what precautions should be taken. To understand the structure and function of multipolar neuron,unipolar and bipolar neurons. Also to identify the structures of a nerve. There are no safety concerns for this lab.

b. Is pigment distribution uniformly in each mycelium? If not, where is the pigment concentrated in each mold?

The purpose of this lab was to practice proper handling of the light microscope, learn the names and functions of the light microscope parts, acquire skill in using the light microscope by carefully following all directions, prepare a wet mount, and locate objects under low and high power magnification. In addition, we will learn to position objects when viewed with a microscope, adjust the diaphragm correctly to achieve proper light under low and high power, learn to locate objects at various places in the “depth of field” and use stains (iodine) as an aid.

When the condition of lacking glucose and more ATP is needed for functioning is occurring, glycogen will be broken down into glucose, and then glucose will be going through glycolysis, Krebs cycle, and electron transport system. The process that link glycolysis in Krebs cycle is called as oxidative decarboxylation (Lee, 2009). The glycolysis of glucose will used up 2ATP molecules to produce 2 pyruvic acid (C3) and 4ATP (net gain= 2ATP), followed by the Krebs citric acid cycle that used up 2 pyruvic acid (C3) to produce 2 sets of 3CO_2 + 4NADH + FADH_2 + ATP and other molecules (net gain= 6NADH + 6H^+ + 2FADH_2 + 2ATP + 4CO_2)

This glucose molecule then becomes the key ingredient for Mr. Euglena’s aerobic respiration, the process where glucose is broken down into molecules of ATP in the presence of oxygen. A molecule of ATP is ADP having a high energy bond with phosphate (P). When this bond is broken, it releases energy in order for the cell to carry out life functions. The glucose molecule produced by the dark reaction of photosynthesis makes its way to the cristae on the inner membrane of the mitochondria. In the cristae, the process of aerobic respiration occurs. There are three steps in aerobic respiration: glycolysis, the Krebs Cycle (citric acid cycle), and the cytochrome chain (electron transport system). The first step is glycolysis. Glycolysis

Purpose : The purpose of this lab is to understand the metabolic process of the cellular respiration by which it produce and convert energy. Moreover, an overview of the four major processes of the cellular respiration which is glycolysis, pryuvate the citric acid cycle, and the electron transport chain

Benoit, Pruitt, and Thrall study if a wet washcloth or gauze has the same photon absorption ability as Superflab and compare the effect of an air gap between tissue equivalent bolus and skin. The researchers have independent variables of two 1.0cm thick Superflab and wet gauze materials; also two 0.5cm thick SuperFlab and wet gauze materials all with surface areas of 15.5cm x 15cm. They use a linear accelerator, which produces 6 MV photons, to collect ionization measurements with a parallel plate ionization chamber measured by an electrometer, using three different independent physical densities of 0.75, 1.02 and 1.20g/cm^3. In regards to absorption and effects of air gaps, there is more variation in smaller field sizes (4x4cm^2) when compared

The Krebs cycle is a series of reactions which occur in the mitochondria and results in the formation of ATP and other molecules which undergo farther reactions to form more ATP. Cellular respiration can be divided into four sequences. The first sequence is glycolysis, its breaks down one molecule glucose into two molecules pyruyate. Transition takes place in the matrix of the mitochondria and it’s referred to the beginning of aerobic respiration. The process takes place if there is enough amounts of oxygen in the mitochondria. However if there is insufficient oxygen in the mitochondria it could result into fermentation. Transition Reactions take place in the pyruvate molecule. In transition reactions two hydrogen electrons and one carbon

Mitochondria has many key molecules that are present within the organelle. Some of these molecules include oxaloacetate and succinate dehydrogenase, both in which play important roles in cellular respiration. Both of these substrates are essential for the Krebs Cycle, as they both produce ATP within the cycle (Wojtczak, Lech & Wojtczak, A.B. & Ernster, L. 1969). The shape and structure of the molecule oxaloacetate is similar to the components of the molecule succinate dehydrogenase. An active site is part of an enzyme in which a protein or substrate binds to an enzyme (“Active Site.”). Normally,

Hans Kreb received the Nobel Prize for discovering the metabolic cycle in 1953. He worked under the guidance of Otto Warburg at the University of Freiburg where he was introduced to techniques which helped to study the rate of cellular respiration using ‘tissue slice method’ and Warburg manometer. These techniques were instrumental in understanding respiration at cellular level rather than whole organism level.

This ensured that our experimental samples were only showing readings for the light absorbed by the DPIP and not by the mitochondrial suspension as well. Tube 1 consisted of 4.4 ml buffer, 0.3 ml DPIP, 0.3 ml mitochondrial suspension, and 0 ml of succinate. This served as a control because there was no succinate to give off electrons and reduce the DPIP. Tube 2 consisted of 4.3 ml buffer, 0.3 ml DPIP, , 0.3 ml mitochondrial suspension and 0.1 ml succinate. This was the trial with a low concentration of substrate. Tube 3 had 4.2 ml buffer, 0.3 ml DPIP, 0.3 ml mitochondrial suspension and 0.2 ml succinate. This final tube was used to notice the effect of increased substrate on the amount of electrons given off, or the amount of DPIP reduced. We also made sure to add succinate to each tube last, so that the succinate to fumerate reaction would not occur before the DPIP was there to accept the electrons. Immediately after creating each cuvette, we covered it in parafilm to minimize contamination and placed it directly in the spectrophotometer to get an accurate reading. We recorded the absorbance of cuvettes 1, 2, and 3 every 5 minutes for the next thirty minutes and recorded the absorbances in a table. We also made sure to properly mix the contents of the cuvettes thoroughly before getting a reading in order to best distribute the DPIP throughout the solution.

The citric acid cycle — also known as the tricarboxylic acid cycle (TCA cycle), the Krebs cycle, or the Szent-Györgyi-Krebs cycle, [1][2] — is a series of enzyme-catalysed chemical reactions, which is of central importance in all living cells that use oxygen as part of cellular respiration. In eukaryotic cells, the citric acid cycle occurs in the matrix of the mitochondrion. The components and reactions of the citric acid cycle were established by seminal work from Albert Szent-Györgyi and Hans Krebs.

Mitochondrion produces the energy that cell needs by breaking down sugars, fatty acids and amino acids to CO2 and H2O. In this process, which is called cellular respiration, the chemical energy in sugar, fatty acid and amino acid molecules is captured as ATP. Krebs cycle is a part of the cellular respiration that consists of series of reactions. And succinate dehydrogenase is one of the enzymes that is used in this cycle. It basically catalyzes the oxidation of succinate to fumarate. In this reaction, succinate reduces a FAD molecule, which eventually donates its electrons to coenzyme Q. However, Azide prevents FADH2 from giving its electrons to coenzyme Q, rather than an artificial electron acceptor, DCIP takes the electrons. DCIP is a dark blue solution that gets lighter as it gains electrons. As DCIP gets lighter, its absorbance will decrease. So, the rate of the reaction can be relatively observed by looking at the absorbance values of DCIP since the reaction processes, DCIP gains electrons and gets lighter in color. By spectrophotometry we took the absorbance values. Spectrophotometer is used in the process, which sends beams of light to the sample and measures the intensity of the light that passes through the sample. This way we can

Present study is based on laboratory work; however the plant material for experimental purpose will be collected from experimental farm of CSIR-IIIM (32.73N and 74.87E).