BIO 115 labs
Lab 8; Photosynthesis -Which of the following statements about chlorophyll is correct?
It reflects light in the green light spectrum. Chlorophyll is a plant pigment that absorb specific wavelengths of light energy and reflect back the green wavelengths of light that chlorophyll pigments cannot absorb.
Lab 1; Safety -Personal protective equipment may include:
Lab coat or apron Gloves Goggles or lab safety glasses Closed toe and covered heel shoes Long hair should be tied up to meet proper laboratory safety protocols.
Lab 1; Safety - overview
This simulation is meant to describe the most strict laboratory precautions. You should learn the reason for each of these precautions but follow the rules set by your own lab instructor or supervisor.
Lab 2; Quantification - mass - Before you begin
To "tare a scale" means to set the electronic reading to zero before weighing an item. Be sure to hit the tare button before weighing an object.
Lab 3; Biomolecules - which tube has highest sugar concentration
Tube B
Lab 3; Biomolecules - sugars - Michael tested 4 different solutions of variable glucose concentration with Benedict regent. what are the possible explanations for the result observed in tube c?
Tube C was not heated for the correct amount of time. The solution added to Tube C did not contain simple sugar
Lab 3; Biomolecules - sugars - overview
Various sugar molecules are vital to survival. However, having too much or too little sugar can be harmful to your health. You should be able to measure the sugar content of substances to learn if they are healthy food options. In this simulation, you will perform a Benedict test on four unknown solutions to test for the presence and relative concentration of simple sugars. The unknown solutions are either water or contain varying concentrations of simple sugars.
Lab 2; Quantification - When measuring the volume of a liquid in a graduated cylinder, at which point should the measurement be taken?
at the bottom of the meniscus
Lab 8; Photosynthesis -Which of the following is NOT a product of the light reaction?
carbon dioxide the photosynthesis reaction requires light, water, and carbon dioxide as reactants and produces carbohydrates (like glucose) and oxygen during the process.
Lab 8; Photosynthesis -pigments - What is the purpose of using extract from chloroplasts?
chloroplasts contain the photosynthetic pigments. To separate the photosynthetic pigments, we must collect them where they are located in the chloroplasts.
Lab 2; Quantification - Which properties of water contribute to the formation of the meniscus? Select all that apply.
cohesion and adhesion Water molecule stick together (cohesion) because of the hydrogen bonds between water molecules. Water molecules are attracted (adhesion) to other material like the sides of the glass beaker. These two forces create the C-shaped curve/meniscus.
Lab 2; Quantification - Assume you drink 250mL of soda out of a 1 liter soda bottle. How many liters are left?
0.75 liters
Lab 3; Biomolecules - polysaccharide
A carbohydrate made up of hundreds to thousands of sugar molecules linked together.
Lab 3; Biomolecules - Oligosaccharide
A carbohydrate made up of more than two sugar molecules linked together.
Lab 3; Biomolecules - Disaccharide
A carbohydrate made up of two sugar molecules linked together.
Lab 3; Biomolecules - Maltose
A disaccharide consisting of two glucose molecules bound together.
Lab 3; Biomolecules - starch - Glucose and starch are both carbohydrates. Why does glucose produce a negative result when testing using iodine?
Iodine only tests for polysaccharides, and glucose is a monosaccharide.
Lab 8; Photosynthesis - key concepts
- Plants use carbon dioxide and the energy from the sun during photosynthesis to produce glucose. - Photosynthesis is a combination of multiple chemical reactions. -A reactant of photosynthesis whose general levels can be measured is carbon dioxide. -A product of photosynthesis that can be measured is oxygen. -Carbon dioxide molecules react with water molecules using light energy to produce oxygen, water, and a glucose molecule.
Lab 8; Photosynthesis - - comparing key concepts
-Glucose produced by photosynthesis is used by plants in aerobic cellular respiration pathways to produce ATP (adenosine triphosphate), which provides energy to power many cellular reactions. Aerobic cellular respiration pathways also require oxygen. In cellular respiration oxygen reacts with glucose to produce carbon dioxide and water. -White light is made up of a range of wavelengths from red with the longest wavelength to violet with the shortest wavelength. Each group of wavelengths has a characteristic color. -Plants absorb certain wavelengths of light for photosynthesis better than others. -Plants are green because the green wavelength is mostly reflected back to our eyes.
Lab 8; Photosynthesis - comparing overview
-Light is crucial to providing the energy needed for photosynthesis. -One method to observe the progress of photosynthesis is to monitor the production of one of its products, oxygen. In this simulation, you will :Assemble a volumeter. Measure the change in the volume of oxygen produced during photosynthesis using a volumeter. Compare rate of photosynthesis in Elodea plants exposed to green or blue light in order to determine if one wavelength of light is better for photosynthesis. -Elodea is a plant that lives in water. Photosynthesis will be measured in these plants. -The reactants for photosynthesis are provided by sodium bicarbonate solution and light. -Sodium bicarbonate (NaHCO3) solution provides carbon dioxide and water, and light provides the energy needed for photosynthesis.
Lab 1; Safety - before you begin
-in this simulation, you will see a student entering the laboratory. -You will be able to see the materials on the lab bench and assess potential hazards in the lab scenario. -You should determine which precautions are available and necessary for three specific scenarios. Rat dissection pH testing Microbial staining
Lab 2; Quantification - mass - Overview
In this simulation, you will learn about units of weight in the metric system. You will learn how to tare and accurately use a scale. You will use a scale and a beaker to measure the weight of a spoonful of salt (sodium chloride).
Lab 8; Photosynthesis - before you begin
-pH is a measure of the amount of hydrogen ions in a solution. The greater the amount of hydrogen ions, the more acidic the solution. As hydrogen ions are removed from a solution it becomes more basic. -Carbon dioxide combines with water to form carbonic acid. Therefore, the more carbon dioxide in a solution, the more acidic it will be. -Phenol red is a pH indicator that turns yellow in an acidic environment. -Phenol red appears pinkish-red in basic solutions.
Lab 3; Biomolecules - Benedict Test for Sugar
A light blue solution that tests for many types of simple sugars, including maltose and glucose. Benedict reagent goes through a series of color changes to indicate the amount of simple sugars present. Light blue (original color) = no simple sugars. The color then progresses through green, yellow, orange, red, and brown as the amount of simple sugars increases.
Lab 3; Biomolecules - starch
A plant-based polysaccharide.
Lab 3; Biomolecules - sugars - Before you begin
A positive result for the Benedict test occurs anytime the reagent changes from its original blue color. Relative concentration of simple sugar can be determined by color. Blue represents the lack of simple sugars. The color then progresses through green, orange, and red as the amount of simple sugars increases.
Lab 3; Biomolecules - Glucose
A small, six-carbon sugar molecule found in starch and glycogen. A common monosaccharide.
Lab 3; Biomolecules - Iodine
A solution that turns from brown to purple in the presence of starch.
Lab 8; Photosynthesis - comparing - before you begin
A volumeter allows the measurement of volume change due to displacement of a liquid. The liquid may be displaced by addition or removal of a substance, such as oxygen.
Lab 2; Quantification - Where do you need to orient your eye level to take an accurate reading of the meniscus?
Accurate volume measurements are taken at the bottom of the water level (meniscus) with your eye level parallel to the water level.
Lab 3; Biomolecules - glycogen
An animal-based polysaccharide.
Lab 3; Biomolecules - Negative Control
Any procedure that is known to NOT produce the desired result. A negative test result means what you are looking for is NOT present.
Lab 3; Biomolecules - Positive Control
Any procedure that is known to produce the desired result. A positive test result means what you are looking for is present.
Lab 8; Photosynthesis - hypothesis
As photosynthesis progresses, the level of carbon dioxide will decrease.
Lab 3; Biomolecules - sugars - key concepts
Benedict reagent is used to identify simple sugars. A positive result for the Benedict test occurs anytime the reagent changes from its original blue color. The reaction requires heat to take place. You need to use clean equipment when testing chemicals to prevent contamination.
Lab 8; Photosynthesis -what are the reactants for photosynthesis
CO2 (provided by sodium bicarbonate) and H2O
Lab 8; Photosynthesis - Why are carbon dioxide levels changing in the tube with Elodea?
Carbon dioxide levels are dropping because carbon dioxide is a reactant in photosynthesis.
Lab 8; Photosynthesis - pigments - overview
Chlorophyll extract appears green, hiding the presence of multiple pigments. It is possible to visualize the different pigments found in chlorophyll by separating them. One method of separation is paper chromatography. In this simulation, you will:Use paper chromatography to separate different photosynthetic pigments in a chloroplast solution.Identify different photosynthetic pigments based on their color. There are four distinct groups of photosynthetic pigments that each absorb different wavelengths of light:Chlorophyll a (absorbs red-violet light, appears blue-green)Chlorophyll b (absorbs red-violet light, appears yellow-green)Carotenes (absorterm-50b blue-violet light, appear orange)Xanthophylls (absorb blue light, appear yellow)
Lab 3; Biomolecules - fats - Based on your observations which of the following do you think will have a positive result for lipids?
Coffee creamer
Lab 8; Photosynthesis -pigments - pigment colors
During paper chromatography, the different photosynthetic pigments of the chloroplast extract migrate up the chromatography paper. The pigments that are more soluble will migrate farther than those that are less soluble. Examine the bands produced on your chromatography paper. Each band represents a different pigment of your starting extract. Chlorophyll a is blue-green. Chlorophyll b is yellow-green. Carotenes are orange. Xanthophylls are yellow.
Lab 8; Photosynthesis -Which of the following represents a reactant or input for the light reaction of photosynthesis?
H2O The photosynthesis reaction requires light, water, and carbon dioxide as reactants and produces carbohydrates (like glucose) and oxygen during the process
Lab 3; Biomolecules - before you begin
How to interpret the starch test:A positive test result for starch occurs when iodine turns color. Medium blue is a small amount of starch, dark blue indicates a medium amount of starch, and blue-black indicates a large amount of starch. A negative test result for starch occurs when iodine stays yellow.
Lab 2; Quantification - volume - before you begin
How to read a graduated cylinder Water adheres to the glass walls of a graduated cylinder, creating a curved appearance termed a meniscus. Accurate volume measurements are taken at the bottom of the meniscus with your eye level parallel to the meniscus. In the above image, the measurement is 25 mL.
Lab 8; Photosynthesis -comparing - Strategy
I will compare the rate of photosynthesis of green light and blue light.
Lab 8; Photosynthesis -white light strategy
I will compare the rate of photosynthesis with and without white ligh
Lab 8; Photosynthesis -white light method
I will measure the volume change due to O2 production using a volumeter.
Lab 8; Photosynthesis - strategy
I will place a plant in an environment with carbon dioxide and light for photosynthesis to occur. I will use a pH indicator to monitor the level of carbon dioxide. I will compare the results to a negative control without a plant.
Lab 2; Quantification - volume - overview
In this simulation, you will learn about units of volume in the metric system. You will learn how to measure the volume of liquids and objects. You will use a graduated cylinder to measure the volume of liquids and solid objects.
Lab 2; Quantification - mass - Key Concepts
Metric units are used in scientific research to ensure consistency of collected data. The metric system uses four basic units from which all others are calculated: Grams (g) for weight Meters (m) for length Liters (l) for volume Degrees Celsius (°C) for temperature This gives all scientists the same standards of measurement when they conduct experiments. The base metric unit for weight is the gram (g). A milligram (mg) is 1000 times smaller than a gram (g). A kilogram (kg) is 1000 times larger than a gram (g).
Lab 8; Photosynthesis -pigments - before you begin
Molecules of different sizes can be separated using paper chromatography. In this technique, chloroplast extract is placed at the end of chromatography paper and the end is placed in a solvent. The solvent carries the molecules as it migrates up the paper. In this way, the molecules are separated. Molecules are separated based on their chemical composition. Readily soluble molecules move the farthest compared to molecules more strongly attracted to the chromatography paper. Paper chromatography works by separating the different photosynthetic pigments into bands. Click the button below to learn more about these pigment bands.
Lab 3; Biomolecules - monosaccharide
One individual molecule of sugar; the building blocks of carbohydrates
Lab 8; Photosynthesis - overview
One method to observe the progress of photosynthesis is to monitor the removal of one of its reactants, carbon dioxide. In this simulation, you will:Identify the uptake of carbon dioxide due to photosynthesis and compare it to a negative control.
Lab 3; Biomolecules - fats - Select the papers that contain fat.
Paper A and Paper B
Lab 3; Biomolecules - fats - Match the papers to the most likely contents of each bottle.
Paper A: Oil Paper B: Milk Paper C: Glucose Paper D: Water
Lab 3; Biomolecules - protein - Select the tubes that contain protein. Which one has the highest amount of protein
Pepsin and Albumin; Pepsin has highest amount
Lab 8; Photosynthesis -comparing - Why does blue light lead to a greater rate of photosynthesis compared to green light?
Plants absorb certain wavelengths of light better than others for use in photosynthesis. Green light is reflected back and its energy is not fully available for use in photosynthesis.
Lab 8; Photosynthesis -comparing - conclusion
Plants exposed to blue light will show a greater rate of photosynthesis compared to those exposed to green light.
Lab 8; Photosynthesis - pigments - key concepts
Plants use carbon dioxide and the energy from the sun during photosynthesis to produce glucose. White light is made up of a range of wavelengths from red with the longest wavelength to violet with the shortest wavelength. Each group of wavelengths has a characteristic color. Plants use multiple photosynthetic pigments to absorb light energy used in photosynthesis. The wavelengths of light absorbed can be used in photosynthesis, and the wavelengths of light reflected are what we observe.
Lab 3; Biomolecules - proteins - Key concepts
Proteins are a very diverse group of molecules with many important functions. Proteins are polymers consisting of long chains of amino acid monomers. A) Two amino acids form a dipeptide .B) Multiple amino acids folded to form a functional structure make up a protein. The "R" in the amino acid structure represents any one of 20 possible functional groups found in the amino acids used in biological systems.
Lab 3; Biomolecules - proteins - overview
Proteins are the most functionally diverse group of macromolecules in living systems. It is important to be able to test for the presence of proteins in solutions. In this simulation, you will perform a Biuret test on starch, pepsin, and albumin solutions to test for the presence and concentration of protein.
Lab 1; Safety - What types of hazards should you protect yourself from in the laboratory?
Splattering Sharp objects Spills Flame Corrosive chemicals
Lab 3; Biomolecules - starch - key concepts
Starch is a polysaccharide consisting of long chains of glucose. Iodine is a yellowish-brown colored liquid that turns blue or black when it contacts starch. You need to use clean equipment when testing chemicals to prevent contamination. polysaccharide
Lab 3; Biomolecules - starch - overview
Starch is a storage form of carbohydrates in plants. As a food source, starch is vital to survival. Testing for starch content helps you more clearly understand food choices. In this simulation, you will perform an iodine test on potatoes and onions to test for the presence of starch. You will use positive and negative controls to verify your results.
Lab 8; Photosynthesis - What is happening to the level of carbon dioxide in the experimental test tube with the Elodea leaf as indicated by the red color in the tube?
The level of carbon dioxide is decreasing.
Lab 8; Photosynthesis - What is happening to the level of carbon dioxide in the negative control test tube without the Elodea leaf as indicated by the yellow color in the tube?
The level of carbon dioxide is unchanged.
Lab 8; Photosynthesis -A student set up a test tube containing sodium bicarbonate and topped it with a volumeter, but forgot to add the Elodea plant! Which of the statements below gives the result that the student would be likely to observe?
The level of the liquid in the volumeter would remain constant since gas is neither being produced nor being used.
Lab 8; Photosynthesis -pigments - What is the purpose of the chromatography solvent?
The pigments dissolve in the chromatography solvent, which allows them to be separated. As the solvent moves up the paper, the pigments are carried along and are separated.
Lab 8; Photosynthesis -comparing - hypothesis
The rate of photosynthesis is greater for blue light than for green light.
Lab 8; Photosynthesis -white light hypothesis
The rate of photosynthesis is greater in white light than in darkness.
Lab 8; Photosynthesis -What would you expect to happen if you compare the rate of photosynthesis in bright white light and in darkness?
The rate of photosynthesis will be greater in bright white light than in darkness. Since photosynthesis requires light to proceed, the rate of photosynthesis would increase when exposed to white light compared to darkness.
Lab 8; Photosynthesis -In paper chromatography, photosynthetic pigments from a plant pigment extract will separate due to their (Check all that apply)
differences in solubility in a chromatography transport solution (mobile phase). differences in affinity for the chromatography paper (stationary phase). Pigments responsible for photosynthesis can be separated based on their chemical composition on chromatography paper. Molecules that are soluble in the transport solution will move up the chromatography paper more quickly than the molecules that are attracted to the paper.
Lab 2; Quantification - In the metric system, the base unit of weight is the
gram.
Lab 8; Photosynthesis -A new plant species has a unique photosynthetic pigment. The leaves of this plant appear to be blue-green. What wavelengths of visible light does this pigment reflect?
green and blue Plant pigments absorb specific wavelengths of light energy and reflect back the wavelengths of light that they cannot absorb. The reflected wavelengths of light give the plant or flower its color, in this case green and blue were reflected back making the flower appear green/blue.
Lab 8; Photosynthesis -Of the visible light spectrum, the rate of photosynthesis is worst under
green light The least amount of light absorption occurs at 550 green color range, therefore this is the lowest rate of photosynthesis.
Lab 8; Photosynthesis -Why is a 3% sodium bicarbonate (NaHCO3) solution added to each test tube?
it is a source of water and carbon dioxide
Lab 8; Photosynthesis -pigments - why does chlorophyll b appear to be yellow?
it reflects light in those wavelengths and absorbs violet and red
Lab 2; Quantification - Which of these items can be placed in the regular trash can or recycle container?
lab notes that are no longer needed that were used during a lab that did not contain dangerous chemicals or infectious organisms.
Lab 3; Biomolecules - simple sugar
monosaccharides and disaccharides
Lab 2; Quantification - Which of the following items should be disposed of in the Sharps container?
needles, glass pipettes, broken glass, scalpel blades
Lab 2; Quantification - In which circumstance is food and/or beverage allowed in the laboratory?
never
Lab 8; Photosynthesis -do you expect photosynthesis to occur without light
no. light energy is needed
Lab 8; Photosynthesis - Why is phenol red added to the test tubes?
phenol reed is a pH indicator
Lab 8; Photosynthesis - What is the initial color of the test tube?
pinkish - red
Lab 8; Photosynthesis -based on your results, what can you conclude from this experiment
plants exposed to white light will undergo photosynthesis and produce oxygen
Lab 2; Quantification - The purpose of lab safety rules and protocols is to
protect everyone in the lab from injury and infection.
Lab 8; Photosynthesis -How does a phenol red-containing solution look if CO2 level is low?
red Phenol red solution is red if carbon dioxide levels are low (alkaline pH). Phenol red solution is yellow if the carbon dioxide level is high (acidic pH).
Lab 2; Quantification - In the weight exercise, the tare button was used to
reset the scale.
Lab 8; Photosynthesis -Why do you cover one test tube in aluminum foil?
the foil blocks light
Lab 8; Photosynthesis -pigments - why did the different photosynthetic pigments migrate to different points on the chromatography paper
the pigments differ in their solubility in the solvent and affinity for the paper
Lab 8; Photosynthesis -Why is the volume level for the Elodea covered with foil decreasing
the plant is undergoing cellular respiration and is consuming oxygen. A plant in darkness will consume oxygen when it conducts aerobic cellular respiration using glucose reserves, and new oxygen is not produced because photosynthesis is not occurring.
Lab 8; Photosynthesis -Why is the volume level for the Elodea exposed to white light increasing?
the plant is undergoing photosynthesis and producing oxygen. The addition of oxygen is displacing the liquid in the volumeter.
Lab 8; Photosynthesis -what do the white light (solid red) and darkness (stripped orange) bars represent
the solid red bar shows how oxygen volume increases due to photosynthesis, and the striped orange bar shows how oxygen volume decreases to due aerobic cellular respiration and a lack of photosynthesis
Lab 2; Quantification - This image illustrates what correct safety practices? (Select all that apply)
use of gloves and eye protection, tying back long hair, uncluttered work bench, wearing of lab coat
Lab 8; Photosynthesis -white light graph
y axis - rate of volume change x axis - presence of light
Lab 8; Photosynthesis -Acidic solutions will appear what color?
yellow