Question

Bio 121

I need to make (yeast fermentation) lab report.

This is the lab experiment and results:

General Biology BIO121 Yeast Fermentation Lab Introduction Organisms stay alive by the utilization of energy through metabolism. The energy acquiring pathways in photosynthesis convert radiant energy from the sun into the chemical bond energy of carbohydrates. This photosynthetic process is limited to the producers or autotrophs, which include plants, photosynthetic bacteria and some protists. Energy releasing metabolic pathways include: glycolysis, fermentation, aerobic respiration and anaerobic electron transport or respiration. Catabolism of a molecule of 6-carbon glucose to two 3-carbon pyruvate molecules is an anaerobic process, which occurs in the cytoplasm and is termed glycolysis. The energy releasing pathways all start with glycolysis and the fate of the pyruvate depends on the cell type and environmental conditions. Cellular respiration is the aerobic process whereby cells can extract the potential chemical bond energy of glucose, or other fuel sources such as lipids or proteins, and convert that energy into the potential chemical bond energy of ATP. Per molecule of glucose, the ATP yield is 36-38 ATP molecules depending on the cell type. Oxygen is not available in all environments. Marshes, bogs, deep-sea sediments, the animal gut, canned foods and sewage treatment ponds are some anaerobic environments. Aerobic cellular respiration is not an option and organisms living in these conditions practice anaerobic glycolysis and fermentation. Some of these fermenter organisms die if exposed to oxygen, such as the bacteria responsible for the diseases of botulism and tetanus. Other kinds of fermenters are indifferent to the presence of oxygen, such as the lactobacillus used to manufacture yogurt. Still others can use oxygen, if available, and also practice fermentation when oxygen is limited, such as your muscle cells or yeasts. Fermentation yields no new ATP, but allows for the regeneration of NAD+ox to be used in glycolysis (Figure 1). Glycolysis produces the net yield of two ATP's per molecule of glucose (Step 1 in Figure 1). This allows an organism to continue to convert energy for its cellular metabolic activities. Fermentation yields enough energy to sustain many single celled anaerobic organisms. Fermentation even aids some aerobic cells through times of stress, but does not provide enough energy to sustain a large, active multicellular organism. There are two types of fermentation: lactic acid fermentation and alcohol fermentation. In lactic acid fermentation, pyruvate (pyruvic acid) is converted into lactate (lactic acid) using the electrons and hydrogens from NADHred +H and liberating NAD*ox. The regenerated NAD can return to the glycolysis pathway. Examples include the manufacture of cheese, yogurt and sauerkraut. Lactate fermentation also occurs in human muscle cells under decreased oxvoen conditions. This is advantageous only for a short duration because fermentation depletes the C 03/12/17 ned with CamScanner

This is a guide to making the lab report:

Answer 1

Fermentation

Introduction

Fermentation process is breaking down of sugars to generate energy without using oxygen. In yeast cells, fermentation produces carbon dioxide and ethanol, while in animals the product is carbon dioxide and lactate or lactic acid.ATP is a form of energy at molecular level. Here, fermentation produce 2 ATP molecule per glucose molecule compared to the 36 ATP produced in aerobic respiration. Different types of Yeasts can utilize different sugars for fermentation, but some carbohydrates are more readily fermented than others. In this experiment, carbon dioxide production and glucose utilization of yeast to ferment will be tested.

Hypothesis I think that with more yeast we put in more carbon dioxide will be produced. So when yeast is mixed with sugar and water a reaction is produced, where the chemicals react to each other and they produce carbon dioxide. Thus more of yeast into the mixture than before the sugar will have more to react therefore creating more carbon dioxide .Hence carbon dioxide production will be increased with the utilisation of the glucose.

Materials and methods

In this lab, the experiment is performed in groups. The available materials are 15 ml of 5 centrifuge tube with perforated lids. 7% of yeast suspension in50 ml beaker likewise 1 % of glucose, 10 % of sucrose, 6 % of galactose is taken in 8 ml for each solution. The other chemicals used for fermentation process are 16 ml of 6 % of lactose, lactic acid, glucose stick , 400 ml of two beakers and 50 0 C water bath. The experiment is divided into 2 process- One is glucose fermentation and another experiment is carbohydrate source effect on fermentation.

Glucose fermentation

one Glucose stik is used for the measurement of glucose concentration and it is entered in the chart as an initial data. Tube 1 is filled with 8 ml of 1%glucose to this tube yeast solution is added to the brim and close the hole with the fingers and shake gently remove the cap and add more yeast solution to fill the tube. The level of the solution at the beginning of the experiment is being recorded. After filling the tube place with 50 degree Celsius of water finally mark measure and record. The glucose concentration with glucose test strip at 10 ,20, 30, 40 and 50 minutes .At 10 ,20, 30, 40, 50 and 60 minutes mark and invert the tube and measure and record the amount of gas collected at the tube during the experiment. Kindly keep the lid the water closed as much as possible to maintain the proper temperature otherwise there will be a leakage of solution into the water. So false result will be recorded after completing the experiment. The beaker is rinsed and placed on the drying rack over sink.

Experiment 2- carbohydrate source or effect on fermentation

In this experiment the group was divided between the partners and each partner has 4 tube .Filled tube- 2 with 8 ml of 10 % sucrose, tube- 3with 8 ml mark with 6 % galactose ,tube -4with 8 ml mark with 6 % lactose and also 4 drops for one scoop of lactic enzyme is added .Glucose stick is used to measure the glucose concentration in each reagent bottle and its information is recorded in the chart. Tube solutions are filled to the brim and place the fingers over the hole and the tube is placed inside the water bath at 50 degree C. At 15, 30 and 45 minute mark measure and record the data of glucose concentration with glucose test strips likewise. At 15 ,30 and 45 minute mark and in what the tube and measure and record on the data amount of gas that has collected at the tube at the end of the experiment rinse the tube and place in to tube bin.

RESULT

EXPERIMENT-GLUCOSE FERMENTATION

ACTUAL TIME CLOCK	ELAPSED TIME MINUTES	Ml .CO2	GLUCOSE CONCENTTRATION
7.30	0	0	>2000
	10	1	1000
	20	2	<2000
	30	3	300
	40	4	1000
	50	4.5	500
8.24	60	5	1000

EXPERIMENT-CARBOHYDRATE SOURCE OF TEMPERATURE

CARBOHYDRATE SOURCE 10% SUCROSE	ELAPSED TIME MINUTES	Ml .CO2	GLUCOSE CONCENTTRATION
TUBE 2	0	0	750
	15	1.50	>2000
	30	1	>2000
	45	2.2	>2000
	60	2.9	>2000

CARBOHYDRATE SOURCE 5% GALACTOSE	ELAPSED TIME MINUTES	Ml .CO2	GLUCOSE CONCENTTRATION
TUBE 3	0	0	250
	15	1.50	100
	30	1	300
	45	2.2	300
	60	2.9	300

CARBOHYDRATE SOURCE 5% LACTOSE	ELAPSED TIME MINUTES	Ml .CO2	GLUCOSE CONCENTTRATION
TUBE 3	0	0	NEGATIVE
	15	1.50	>2000
	30	1	NEGATIVE
	45	2.2	NEGATIVE
	60	2.9	NEGATIVE

DISCUSSION

The gas produced is carbondioxide.The result of gas indicate that yeast has been fermented with the help of glucose production.

The graph represent that more concentration of glucose increase more amount gas is been produced.