Category: 1st Semester

Catalase Lab Sample 1

 

 

Enzyme Rate of Reaction for Catalase

 

Introduction:
Enzymes are an important part of life that regulate chemical reactions with in the body. Enzymes speed up chemical reactions in four different ways, one way is heat, another is increasing the rate of reactants, the third way is decreasing the amount of products and the fourth way is enzymes, which speed up reaction without themselves being used up. Enzymes are also involved in digestion, respiration, reproduction, vision, movement, thought, and also in the productions of other enzymes. Simple cells may have as many as 2000 enzymes with each one catalyzing a different reaction. An enzyme can speed up a reaction making it 10, 000,000,000 times faster. An enzyme is a catalyst. A catalyst is a chemical that reduces the amount of activation interim needed for a reaction. Without enzymes a reaction would take much longer than if it had and enzyme. Enzymes also the control the rate and direction of the reaction.
Without catalysts chemical reactions would take much longer that the average human life expectancy. So that would mean that in 76 years only a couple chemical reactions would take place. Since our bodies have enzymes though hundreds of chemical reactions a day. If our bodies didn’t have catalysts our bodily cells couldn’t function. Some bacteria, however, possess a defense mechanism which can minimize the harm done by the two compounds. These resistant bacteria use two enzymes to catalyze the conversion of hydrogen peroxide  back into diatomic oxygen and water. One of these enzymes is catalase and its presence can be detected by a simple test. The catalase test involves adding hydrogen peroxide to a cultures sample or an agar slant.

 

Hypothesis:
The reaction rate of catalase splitting hydrogen peroxide into water and oxygen will increase over time.

Materials:
The materials used consisted of 100 paper H2O2 molecules, a data table, paper, pencil, calculator, scissors, watch with a second hand, and an enzyme rate of reaction catalase worksheet.

Methods:
Cut out 100 hydrogen peroxide paper molecules. Double check to make sure there are only 100 paper molecules and place them in an envelope. Then one person will keep track of the time while another person acts as a catalase and tears the paper hydrogen peroxide molecules in half. The torn paper molecules should be returned to the envelope each time. Another person times the person acting as the catalase.  The time intervals in which the paper molecules are to be ripped are 10 seconds, 20 seconds, 30 seconds, and two different 60second periods of time. The results should be  recorded in a data table. The reaction rate for catalase is figured using the formula:
M2 – M1 = Reaction Rate
T2  –  T1

 

Results:

 

 

Time in Seconds Ripped H2O2 Molecules Rate of Reaction
0-10 5 .5
10-30 13 .4
30-60 31 .6
60-120 61 .5
120-180 91 .5

 

1. What is an enzyme? What are its functions in living things?
chemicals that reduce the amount of activation energy needed for reactions to occur; they are proteins in cells that control metabolic reactions

 

2. Name several things that can affect the functioning of an enzyme.
temperature, pH, and the amount of reactant or product

 

3. Write the chemical equation for the breakdown of hydrogen peroxide by the enzyme catalase.
H2O2   +   Catalase –>  H2O  + O2

 

4. An enzyme’s efficiency increases with greater substrate concentration, but only up to a point. Why?
once all active sites are filled, the enzyme’s reaction rate won’t continue increasing

 

5. If you were allowed to continue this lab and rip hydrogen peroxide molecules for 240 and 300 seconds, what would happen to the reaction rate and why would this happen?
there would be more molecules ripped because of the increased amount of time

 

6. What can you say about the length of time and the reaction rate?
The more time available, the faster the reaction will occur.

 

7. What would happen to the reaction rate if you removed the water and oxygen molecules as soon as they were produced?
The rate of reaction would go even faster

 

Error Analysis:
The counting of the time  may have been off a couple of seconds.

 

Discussion and Conclusion:
The data shows that the more time there is, the more hydrogen peroxide molecules will be ripped. The catalase in the lab ripped about 6 molecules every 5 seconds. The same thing occurs in a cell as more hydrogen peroxide is produced, catalase speeds up breaking down this waste into water and oxygen.

Back

 

 

Catalase Peroxide Lab

 

 

Enzyme Rate of Catalase

 

 

Introduction:

Enzymes are molecular substances found in cells.  Enzymes act as catalysts and most are proteins.  Enzymes bind temporarily to one or more of the reactants of the reaction they catalyze. In doing so, they lower the amount of activation energy needed and thus speed up the reaction.
 Not only do enzymes economize energy usage, but also provide a variety of other functions. Cells uses an enzyme (catalase) to rid itself of a poisonous substance (hydrogen peroxide). The rate at which this occurs depends on the amount of catalase that is available. In this lab we are going to measure the time it takes for a disc of filter paper, soaked with different concentrations of enzyme, to make its way to the top of a plastic vial filled with peroxide.  Rate of enzyme activity = distance (depth of hydrogen peroxide in mm)/time (in sec).

Catalase catalyzes the decomposition of hydrogen peroxide into water and oxygen.  One molecule of catalase can break 40 million molecules of hydrogen peroxide each second.

catalase
2H2O2 —–> 2H2O + O2

Objectives:

Students will prepare various dilute solutions from a 100% enzyme solution.
Students will determine how enzyme concentration affects reaction rate.

 

Materials:

6 medicine cups for dilutions, *catalase stock solution, clear plastic vial, forceps, 18 filter paper disks, Hydrogen Peroxide (H2O2), paper towel, apron, safety glasses, watch with second hand, marker, metric ruler, calculator

* The enzyme has been prepared for you as follows: 50g of peeled potato was mixed with 50 ml cold distilled water and crushed ice and homogenized in a blender for 30 seconds. This extract was filtered through cheesecloth and cold distilled water was added to a total volume of 100 ml. Extract concentration is arbitrarily set at 100 units/ml. ENZYME SHOULD BE KEPT ON ICE AT ALL TIMES!!

Procedure:

  1. Make a series of dilutions of the enzyme catalase using the following table.

 

Final Quantity Needed Concentration of Final Solution mL of Catalase mL of Water
10 ml 100% c10 0
10 ml 80% 8 2
10 ml 60% 6 4
10 ml 40% 4 6
10 ml 20% 2 8
10 ml 0% 0 10

 

 

  1. Use a marking pencil and mark the enzyme solutions as follows: 100%, 80%, 60%, 40%, 20%, and 0%.
  2.  Fill a clear vial with 20 mL of hydrogen peroxide.
  3. Using your forceps, pick up one filter paper disk and submerge it in the 100% enzyme solution for 5 seconds. Continue to hold the disk with the forceps.
  4. Using your forceps, pick up one filter paper disk and submerge it in the 100% enzyme solution for 5 seconds. Continue to hold the disk with the forceps.
  5. Remove the disk from the solution and blot it dry, for five seconds, using your paper towel.
  6. Drop the disk in the hydrogen peroxide and measure the time it takes for the disk to rise up from the bottom. Begin timing as soon as the disk touches the surface of the hydrogen peroxide.
  7. Use the metric ruler to measure the distance the disk sinks into the hydrogen peroxide. multiply by two to determine the entire distance the disk traveled. Enter the time and distance the disk traveled in the column for Trial 1 in the data table below.

 

 

% Catalase

Time in seconds

Distance in millimeters

 Reaction Rate mm/s
Trial 1 Trial 2 Trial 3 Avg. Trial 1 Trial 2 Trial 3 Avg.
100
80
60
40
20
0

 

  1. Repeat the above steps for the remainder of the solutions. Remember to use clean filter paper each time you use a different solution. Enter the times and distances for trial 2 and 3 in their appropriate columns.

Analysis & Conclusion:

1. Which concentration of catalase had the fastest reaction time?

2. Which concentration of catalase had the slowest reaction time?

3. What is catalase & why is it important to cells in your body?

 

 

4. How did you know that catalase was present in the above compounds?

 

5. What 2 substances form when catalase breaks down hydrogen peroxide?

 

6. What type of organic compound is catalase?

7. Produce a line graph of the above data. Use the enzyme concentration as the independent variable and the reaction rate as the dependent variable.

Graph Title:__________________________________________________

Legend:

8.  Based on the graph and overall slope of the line, what can you conclude about the effect of enzyme concentration on reaction rate?

 

 

 

Biomes of the World Solution

Biomes of the World Solution
T + + + C D A R + R L + T + + + S + + E I E B E + A + U + + + + E S + M T T I + D E N + + + + E R U E A O + O I M D H + + R + S O W R + I + T O R E R T + N + H F C O + B R I A R E + O + S + + N A V + E B C B C C + E + + + + I R I T + + I U + R S A V A N N A N N + + V D F E N I R A M + + R I M + O O G R A S S L A N D + A V O R R S U O U D I C E D G + + O E P + + + + + + + + I + + + + R + + + + + + + + A + + + + + + E + + + + + + T + + + + + + + + (Over,Down,Direction) ABIOTIC(7,1,SE) BIOME(12,7,N) BIOTIC(10,6,NW) CARNIVORE(7,6,SE) CONSUMER(1,8,NE) DECIDUOUS(9,12,W) DESERT(6,1,SW) FRESHWATER(1,10,NE) GRASSLAND(1,11,E) HERBIVORE(14,4,S) INTERTIDAL(11,10,N) MARINE(7,10,W) OMNIVORE(13,11,NW) PRODUCER(15,12,N) RAINFOREST(10,10,NW) SAVANNA(3,9,E) TAIGA(7,15,NE) TUNDRA(13,1,S)

 

Biotechnology Notes Bi

 

DNA Technology
All Materials © Cmassengale

Introduction:

  • Biotechnology refers to technology used to manipulate DNA
  • The procedures are often referred to as genetic engineering
  • DNA is the genetic material of all living organisms
  • All organisms use the same genetic code
  • Genes from one kind of organism can be transcribed and translated when put into another kind of organism
  • For example, human and other genes are routinely put into bacteria in order to synthesize products for medical treatment and commercial use
  • Human insulin, human growth hormone, and vaccines are produced by bacteria
  • Recombinant DNA refers to DNA from two different source
  • Individuals that receive genes from other species are transgenic

Viruses & their Structure:

  • Viruses contain genetic material but are not living
  • Host cells are required for their reproduction
  • Viruses are composed of an inner nucleic acid core (genetic material) and an outer protein coat (capsid)
  • Viruses that infect animals have an outer envelope (membrane) that is derived from the cell membrane of the host cell may surround the capsid
  • The genetic material in some viruses is DNA; in others it is RNA

 

 

Viral Reproduction:

  • When viral genetic material enters a cell, it is replicated, transcribed (mRNA is produced) and translated (proteins are produced from the mRNA) by the host cell
  • By this process, the host cell uses the genetic instructions in the virus to make more viruses

Viral DNA ® mRNA ® protein

  • If the viral genetic material is RNA, a DNA copy must first be made before transcription and translation can occur
  • The DNA copy of the viral RNA is called cDNA.

viral RNA ® cDNA ® mRNA ® protein

Bacteriophages:

  • Bacteriophages are viruses that infect bacteria
  • Not surrounded by a membrane as the animal-infecting viruses
  • Virus attaches to the bacteria cell, a viral enzyme digests away a part of the wall, and its viral DNA enters the host cell
  • Inside the host cell, the viral DNA is transcribed, translated, and replicated
  • Translation produces protein coats and the enzymes needed in the construction of new virus particles
  • Viral DNA is replicated
  • The protein coats and DNA are assembled into new viral particles
  • The host cell wall to ruptures releasing the newly formed viruses

  • Upon entering the cell, the viral DNA may instead, become integrated into the bacterial DNA
  • It is replicated along with the host DNA when the host reproduces
  • Eventually, it will become transcribed and translated

Retroviruses:

  • Contain RNA & the enzyme reverse transcriptase
  • Reverse transcriptase can make a DNA copy of the viral RNA
  • The new DNA produced from the RNA template is called cDNA
  • DNA synthesis follows the production of cDNA to produce a double-helix
  • cDNA then becomes incorporated into the host DNA (called a prophage)
  • The new viruses escape the host cell by budding
  • The AIDS virus (HIV) is an example of a retrovirus

 

Vectors

  • Vectors are used to transfer genes into a host cell
  • Plasmids & viruses are the most commonly used vectors
  • A vector must be capable of self-replicating inside a cell
  • Viruses are the vectors of choice for animal cells
  • Marker genes can be used to determine if the gene has been taken up

Plasmids:

  • Small rings of DNA in bacterial cells
  • Used to transfer genes to other organisms
  • Host bacterium takes up the plasmid, which includes the foreign gene
  • When bacteria reproduce, plasmids with the new gene are also reproduced 
  • This clones (copies) the gene each time the bacteria reproduces

Viruses:

  • Can accept larger amounts of DNA than plasmids
  • Once the virus enters the host cell, it also reproduces the foreign gene it carries
  • The copied gene is “cloned”

 

Restriction enzymes:

  • Restriction enzymes were discovered in bacteria
  • Bacteria use them as a defense mechanism to cut up the DNA of viruses or other bacteria
  • Hundreds of different restriction enzymes have been isolated
  • Each restriction enzyme or RE cuts DNA at a specific base sequence
  • For example, EcoRI always cuts DNA at GAATTC as indicated below

  • The sequence GAATTC appears three times in the DNA strand below. As a result, the strand is cut into four pieces

  • Other restriction enzymes cut at different sites, some examples are listed below

 

Enzyme Cutting Site
Bam HI GGATCC
Hae III GGCC
Pst I CTGCAG
Hind I GANTC

 

 

Sticky Ends & Recombinant DNA:

  • Fragments of DNA that has been cut with restriction enzymes have unpaired nucleotides at the ends called sticky ends

  • Sticky ends have complimentary bases, so they could rejoin
  • If the vector and the gene to be cloned are both cut with the same restriction enzyme, they will both have complimentary sticky ends
  • After cutting, the 2 DNA samples are mixed
  • Fragments with complementary sticky ends join together forming recombinant DNA (contains gene from vector & the gene to be cloned)
  • Enzyme DNA ligase seals the fragments together
  • Bacteria such as Escherichia coli are capable of taking up DNA from their environment
  • This process is called transformation
  • CaCl2 and a procedure called heat shock are used to make E. coli cells more permeable so that they take up the modified plasmids more readily

Genomic Libraries:

  • A genome is all of the genes in a particular organism
  • Bacteria or virus vectors can be used to store fragments of the DNA from another species
  • The DNA is cut up into fragments, and the different fragments are inserted into bacteria or viruses
  • The collection of bacteria or viruses is called a genomic library

Polymerase Chain Reaction (PCR):

  • Used to make many copies of small pieces of DNA
  • Procedure requires primers, DNA polymerase, and nucleotides
  • Primers are short chains of about 20 nucleotides that are complimentary to a region in the DNA to be amplified
  • DNA polymerase cannot continue the process unless it has already been started by primers
  • Nucleotides are needed because DNA is composed of nucleotide “building blocks”

  • The DNA is heated to approximately 95o C to separate the two strands of the double helix

  • After the strands are separated, the DNA is cooled to about 50o C, and the primers attach
  • The temperature is raised to approximately 70o C so the polymerase will attach to & copy the strand

  • The DNA replication process repeats itself as the solution is then heated and cooled at regular intervals

 

DNA Fingerprinting (RFLP Analysis):

  • In RFLP analysis, the DNA of an organism is cut up into fragments using restriction enzymes producing a large number of short fragments of DNA
  • Because no two individuals have identical DNA, no two individuals will have the same length fragments
  • Gel electrophoresis is a technique used to separate the DNA fragments according to their size
  • The fragments are placed in wells on a sheet of gelatin, and an electric current is applied to the sheet
  • DNA is negatively charged and will move in an electric field toward the positive pole

  • The smallest fragments will move the fastest because they are able to move through the pores in the gelatin faster
  • Bands will be produced on the gelatin where the fragments accumulate
  • Shortest fragments will accumulate near one end of the gelatin (furthest from the wells), and the longer, slower-moving ones will remain near the other end
  • DNA bands must be stained to make them visible

 

Gene Products & Uses of Genetic Engineering:

  • E. coli is used to produce proteins such as insulin by genetic engineering because it is easily grown
  • To recover the product, E. coli must be lysed or the gene must be linked to a gene that produces a naturally secreted protein
  • Yeasts can be genetically engineered and are likely to secrete the gene product continuously
  • Mammalian cells can be engineered to produce proteins such as hormones for medical use
  • Plant cells take up a plasmid from Agrobacterium
  • Plant cells can be engineered and used to produce plants with new properties such as Roundup Ready soybeans
  • Pseudomonas bacteria has been engineered to produce Bacillus thuringiensis or BT
  • BT bacteria make a toxin against insects, thus producing a natural insecticide   (example – B.T. cotton)
  • Animal viruses can be engineered to carry a gene for a pathogen’s surface protein so the virus can be used as a vaccine 
  • Genetic engineering techniques are being used to map the human genome through the Human Genome Project
  • Could provide tools for diagnosis and possible repair of genetic disease
  • Recombinant DNA techniques can be used for genetic fingerprinting
  • Gene therapy can be used to cure genetic diseases by replacing the defective or missing gene
  • Bovine growth hormone (BGH) increases milk production in cows by about 10%

Safety and Ethical Issues:

  • Harmful organisms may be accidentally produced
  • Organisms that are intended to be released in the environment may be engineered with genes that will eventually kill them
  • There is little legislation on the use of genetic screening and information produced by screening
  • The technology is increasing the ability to diagnose genetic diseases pre-natally, adding new complexity to the abortion controversy
  • Ethical questions have been raised over whether we should modify the genes of humans
  • Genetic screening and gene therapy are expensive and may be unavailable to the poor
  • Biological weapons could be created using biotechnology

BIOLOGY SAFETY CONTRACT

BIOLOGY SAFETY CONTRACT

I, ____________________________ have read the safety rules for the biology classroom and lab and agree to follow all of the safety rules set forth in this contract.  I realize that I must obey these rules to ensure my own safety, and that of my fellow students and instructors.  I will cooperate to the fullest extent with my instructor and fellow students to maintain a safe lab environment.  I will also closely follow the oral and written instructions provided by the instructor.  I am aware that any violation of this safety contract that results in unsafe conduct in the laboratory or misbehavior on my part, may result in being removed from the laboratory, detention, receiving a failing grade, and/or dismissal from the course.

 *Failure to have goggles at the beginning of any lab involving heat, chemicals or glassware (except microscopy) will result in removal from the room and a grade of “0” for the lab.  The removal is required by the State of Arkansas.

I do/do not wear contact lenses.

I do/do not have a medical condition that could result in the need for emergency medical attention (explain here if you do).

Signed (student) _________________________________________Date ___________

_______________________________________________________________________________

Dear Parent or Guardian:

We feel that you should be informed regarding the school’s effort to create and maintain a safe science classroom/laboratory environment.  With the cooperation of the instructors, parents, and students, a safety instruction program can eliminate, prevent, and correct possible hazards.

You should be aware of the safety instructions your son/daughter will receive before engaging in any laboratory work.  Please read the list of safety rules above.  No student will be permitted to perform laboratory activities unless this contract is signed by both the student and parent/guardian and is on file with the teacher, a safety test is passed with a 70% or greater, and a classroom map is constructed by the student.

Your signature on this contract indicates that you have read the Student Safety contract, are aware of the measures taken to ensure the safety of your son/daughter in the science laboratory, and will instruct your son/daughter to uphold his/her agreement to follow these rules and procedures in the the laboratory.

Signed (parent) ________________________________Date ___________

Day phone __________________ Convenient hours ___________________

Evening phone _________________Convenient hours __________________

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