Biology Practical unit 10

True or False: Germinating soybeans will have a higher cellular respiration rate than non-germinating soybeans.

True

Understand how to set up and read a respirometer.

Use a ruler to measure the size of the gas bubble on top of the yeast solution. In this example, tube number 1 is 40 mm. When the tip of the respirometer is submerged, no additional air will enter. As O2 is used up, the pressure of gases inside the respirometer decreases. This causes water to enter the pipette.

Know how to set up and read a respirometer used to measure fermentation.

Volume change (mL)=Initial Volume−Final Volume

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

Describe the relationship between metabolic rate (normalized per gram of body mass) and mass of an animal.

(mm3O2/gram body weight/hr)

In the soybean experiment you used both germinating and non-germinating peas. Which of the peas used more oxygen? Germinating peas Which of the peas used more ATP? Non-germinating peas

1. Germinating peas 2. Germinating peas

During cellular respiration: 1. the gas consumed is 2. the gas released is

1. Oxygen 2. Carbon Dixoide

fermentation

A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.

Know the balanced equation for cellular respiration.

C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATP (glucose) + (oxygen) ----> carbon dioxide) + (water) + (energy)

In the yeast fermentation experiment, what is being produced to cause the gas bubble at the top of the tube to get bigger over time?

Carbon dioxide (CO2)

Know what organism was used in the experiment to measure oxygen consumption due to cellular respiration.

Compare the volume of oxygen consumed by growing (germinating) soybean seeds and nongerminating soybean seeds in order to estimate the amount of cellular respiration occurring.

Know what were the dependent and independent variables in the cellular respiration experiment.

Dependent: the volume of oxygen consumed (the amount of cellular respiration occurring.) by Independent: growing (germinating) soybean seeds and nongerminating soybean seeds

Know what organism was used to study fermentation (common name, Domain, Kingdom) and what kind of fermentation it performs.

Fermentation can be difficult to measure in animal cells, so yeast is often used to observe the results of this process.(fungi) = alcoholic fermentation.

Explain why there was more fermentation occurring using some carbohydrates but not others.

Fermentation produces carbon dioxide, so the height of the gas bubble in the tube is a measure of how much fermentation has occurred. more concentrated sugars (polysaccharides like starch) take more energy to break down because they are larger. Glucose was easier and faster because it is a monosaccharide.

Know which carbohydrates cause more fermentation and explain why.

Glucose > Fructose > sucrose > starch > water Glucose, a monosaccharideFructose, a monosaccharideSucrose, a disaccharideStarch, a polysaccharidewater - not a sugar

Yeast was mixed with a 2% glucose solution and placed in various respirometers at different temperatures. The height of the bubbles in the respirometer was measured every 2 minutes for 10 minutes. Identify the independent variable and the dependent variable in this experiment.

IV: Temperature DV: Height of bubbles in the respirometer

How do they differ (what are the products)?

In bacteria and animal cells, the products of glycolysis undergo fermentation in the cytoplasm to produce lactic acid when the oxygen level is low. This is called lactic acid fermentation.

What kinds of organisms perform the different kinds of fermentation?

In plants and yeasts (fungi) = alcoholic fermentation.In bacteria and animal cells = lactic acid fermentation.

What were the different kinds of fermentation introduced?

In plants and yeasts (fungi), the process of fermentation produces ethanol (alcohol) and carbon dioxide. This is called alcoholic fermentation.

Why is cellular respiration important?

It generates ATP, which cells can use to do work.

Give examples of organisms that perform cellular respiration.

Organisms from all kingdoms of life, including bacteria, archaea, plants, protists, animals, and fungi, can use cellular respiration. All living organisms except some bacteria and yeast undergo cellular respiration.

Explain the purpose of adding KOH (potassium hydroxide) to the respirometer when measuring oxygen consumption due to cell respiration.

Potassium hydroxide (KOH) is used to absorb any carbon dioxide produced in this experiment. It is very toxic and should not come in direct contact with skin or with the seeds. Polyester will not soak up KOH and can be used as a barrier between KOH and the seeds. The respirometer must try to measure both gases at the same time. In order to accomplish this, Potassium Hydroxide (KOH) is added to the device. KOH absorbs carbon dioxide and forms Potassium Carbonate and water.

In the soybean experiment, what chemical was added to the respirometer to absorb CO2? How would the experiment change if you had forgotten to add it?

Potassium hydroxide (KOH) was added to the respirometer to absorb the CO2. If the KOH was not added to the respirometer, the volume of gas in the respirometer would not change (one O2 molecule is consumed for every one CO2 molecule released as a product of cellular respiration). Therefore, you would not be able to measure the rate of respiration (metabolic rate).

cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.

anaerobic respiration

Respiration that does not require oxygen

aerobic respiration

Respiration that requires oxygen

Know how to calculate volume change in the respirometer and oxygen consumption in mL/min.

The graduated side arm contains a drop of red fluid to mark the amount of oxygen consumed from inside the experimental container. Read the left edge of the red marker for consistency.

Which animal will have a highest metabolic rate per gram of body weight (mm3O2/gram body weight/hr)?

smallest weight, fastest metabolic rate?

Describe the effect germination has on cellular respiration.

cells can convert sugar molecules into usable energy using a process called cellular respiration.The amount of cellular responsibilities is greater in germinating seeds.

disaccharide (definition and examples)

double sugars: Sucrose, Maltose, Lactose

polysaccharide (definition and examples)

many sugars : starch, glycogen, cellulose

Know the reactants and products of the process of cellular respiration.

reactants: C6H12O6 (glucose) + 6O2 (oxygen) products: 6CO2 (carbon dioxide) + 6H2O (water) + energy

monosaccharide (definition and examples)

single sugars: glucose, fructose, galactose

germination

the process whereby seeds or spores sprout and begin to grow

Describe fermentation.

when lactic acid is formed when there is not enough oxygen for cellular respiration take place