Yeast can metabolize sugar in two ways, aerobically, with the aid of oxygen or anaerobically without oxygen. The net equation for more than two dozen steps involved in the aerobic respiration of glucose is: C6H12O6 (aq) + 6O2 --> 6H2O (g) + energy (36-38 ATP + Heat) But when yeast ferment sugars anaerobically, CO2 production will cause a change in the pressure of a closed test tube system, since no oxygen is being consumed. We can monitor this pressure as an indication of the rate of anaerobic respiration & metabolic activity of the organism. A gas pressure sensor will be used to monitor the fermentation of the sugar. The net equation for the ten steps involved in anaerobic respiration of glucose is: C6H12O6 (aq) --> 2CH3CH2OH (aq) + 2CO2 (g) + energy (2 ATP + Heat) Both alcoholic fermentation and aerobic respiration are multi-step processes that involve the transfer of energy stored in the chemical bonds of a metabolite (usually glucose) to bonds in ATP (Adenosine Triphosphate).
There are two types of respiration: Aerobic (using oxygen) and Anaerobic (no oxygen). Aerobic respiration produces carbon dioxide and water and releases energy. The equation is: C6H12O6 + 6O2 → 6CO2 + 6H20 + Energy ATP A cell cannot get its energy directly from glucose, so during respiration the energy released from the breakdown of glucose is used to make ATP (adenosine triphosphate). ATP is made from the nucleotide base adenine, combined with a ribose sugar and three phosphate groups. It carries energy around the cell to where it’s needed.
Competitive meaning it would bind to the active site therefore blocking it decreasing enzyme activity, noncompetitive being that it would just simply bind elsewhere and or change the shape of the enzyme causing no feedback. For Example if you take too methanol then you will be given ethanol which is a competitive inhibitor of methanol. This way they would both be competing for the active site, thus blocking the active site from the methanol. As for this lab PTU (phenylthiourea) was tested and will find out at the end of the experiment if it would be a competitive or not competitive inhibitor to Catechol Oxidase (Potato Extract). Will the PTU affect the Catechol Oxidase (Potato Extract) and change colors if the liquids are together.
Deficiency of the enzyme lactase (common in adult mammals) prevents cleavage of the glycosidic link in lactose during digestion. Instead, anaerobic bacteria in the large intestine ferment this sugar, producing gas, abdominal discomfort and bloating. What gas is formed and what metabolic byproduct(s) also are released into the large intestine? b) Briefly describe the differences between the polysaccharides….. i) amylopectin and glycogen ii) amylose and chitin 2. (10 points) The catabolic cycle called glycolysis is the most universal energy-producing metabolic pathway for organisms that live on or near the earth’s surface.
The reagent we use is Benedict’s reagent. Reducing sugar will show positive result while non reducing sugar will not. To test the presence of starch in our next food test, iodine is use. When starch is present the iodine added on it will change its colour from yellow to blue black. For the food test that use to determine the of presence protein we use Biuret test instead of Million’s Test.
Question 12 options: niche biome community population Question 13 The temperature optimum for an enzyme is 37C. What will most likely happen if you increase the temperature from 37C to 50C? Question 13 options: The enzyme activity will not be affected The enzyme activity will increase The enzyme activity will decrease The pH will increase Question 14 When celery is placed in a glass of pure water the solution inside its cells is _____ compared to the water. Question 14 options: selectively permeable isotonic hypertonic hypotonic Question
NADH competitively inhibits enzymes in glycolysis as an example of negative feedback B. The activity of the Krebs cycle drops when there is a high concentration of ATP C. ATP acts on a regulatory site of phosphofructokinase to stop the 2nd phosphate addition D. ATP binds to an allosteric site on an enzyme in the Krebs cycle (9) Which of the following is not an intermediate of the Krebs Cycle? A. Oxaloacetate B. Succinyl CoA C. G3P D. Malate (10) In the ETC… A. Electrons are pulled from one complex to the next due to electronegativity differences B. NADH has lower potential energy than FADH2 C. O2 is the final electron acceptor D. Iron containing proteins within the OMM are being reduced and oxidized (11) In the thylakoid membrane, the proton gradient is generated from which of the following? A.
Common Exam Questions and Answers DNA Name the two components that make up the DNA backbone - Deoxyribose - Phosphate Explain how a DNA mutation can result in a non-functioning enzyme - Change in the triplet code - Changes amino acid sequence (primary structure) - Change in hydrogen, ionic and disulphide bonds - Changes tertiary structure/active site shape - Substrate is not complementary/enzyme substrate complexes can not form The Passage of Water through a Plant Why does the rate of transpiration not equal the rate of water uptake in a plant? - Some is used in photosynthesis - Some is produced in respiration - Some is used to provide turgidity/ stored to provide support Little amount of wind/stomata pits reduce the amount of water lost from a plants leaves, explain why - Water vapour accumulates outside the stomata increasing humidity - This reduces the water potential gradient Antibiotic Resistance Suggest two ways of reducing the transmission of the bacteria MRSA - Isolation/quarantine of infected patients - Screening of patients and doctors - Sterilisation of wards and equipment Frequent treatment with antibiotics can result in resistant strains of bacteria, explain how - Mutation occurs - Producing a resistance gene - Resistant bacteria survive and reproduce - Spread resistance by vertical and horizontal gene transmission Blood and Circulation How does haemoglobin in red blood cells load and unload oxygen in the body? - Loading of oxygen in the lungs where partial pressure of oxygen is high so haemoglobin becomes saturated - Unloading of oxygen in respiring tissues where partial pressure of oxygen is low - Unloading where carbon dioxide concentration is higher, pH is lower and temperature is higher Compare the structural features of arteries and veins Structural features | Arteries | Veins | Valves |
Hypothesis My hypothesis is that the volume of carbon dioxide released from the yeast will be high when it is respiring with glucose and fructose, but with lactose, as it is a disaccharide and the yeast does not contain the enzyme lactase, which is needed to break lactose down. Method 1. For each repeat, the 3 boiling tubes were set up in a test tube rack, each containing 4cm3 of 30% yeast solution and 4cm3 of the 15% sugars: glucose, fructose and lactose. 2. 5 drops of Janus Green solution was then added to the substrate, in order to indicate when the substrate would begin anaerobic respiration.
A plant whose cells are in a hypertonic solution will appear droopy because there is a loss of turgor pressure in each cell. When the concentration of water is the same in the cell and the solute the cell is said to be isotonic and is at equilibrium. There is no net movement of water across the membrane. (Biology Department, 2010). Surface area to volume ratio has a direct effect on the amount of water (as well as nutrients and waste) that can diffuse through the plasma membrane.