Title:  Factors affecting the enzymes reaction rates

Purpose:  observing the differences in the reaction because of the different concentration of enzymes 

Hypothesis: Higher concentrations of lactase drops will react stronger to the milk. As more lactase is put into the milk, the glucose concentration should be higher. 

Materials: 

• Five Test Tubes
• Beaker or Graduated Cylinder  
• [Lactose] milk 
• Lactase
• Glucose test strips 

 Introduction

In this lab, we will be adding the lactase enzyme to 5 test tubes containing 20ml of milk, and then testing the glucose levels in these test tubes after 10 minutes. We believe the concentration of the enzyme in the milk with affect the glucose levels by increasing them as we add more of the enzyme. 

Procedure: 

1. Put 20mL milk in each test tube
2. Put no drops of lactase enzymes in the first test tube, add 2 drops lactase enzymes in the second tube, add 4 drops lactase in test tube 3, 6 drops in tube 4, 8 drops in tube 5
3. Wait for 10 minutes
4. Use the glucose test strips to see how many glucose is in the test tube 

Results (Data + Observations)

Data Analysis/Conclusion 

After conducting our experiment, we noticed that our data is not consistent with what we expected. We thought that there would be an increase in glucose as we added more drops however, the glucose levels fluctuated. It started with an increase from 0-2 drops, then an even larger jump from 2-4 drops. After that, the glucose levels decreased with 6 drops and then rose again with 8 drops. This could have been an error in how we handled the procedure (as mentioned below) and so we cannot make an accurate conclusion based off of this data. Had we received the data that we predicated however, we could have said that our conclusion is that when you add more lactase to lactose, glucose levels rise. 

Errors / Improvements 

The result of this test is not the same as what we thought, there are several reasons that might cause the data to be inaccurate. First, we should shake the test tubes after we put the enzymes into the milk. By shaking it, it could help to make the reaction happen properly. And we can also reduce the number of drops that we put in each test tube, which could give us a more detailed result

1. How is mRNA different than DNA?

DNA carries the instructions to build protein, it is big and has two backbones. mRNA is single-sided and short, it copies the information carried by 1 gene on DNA and carried this message to the ribose. The function of DNA and mRNA are different.

2. Describe the process of transcription

When one DNA translated into mRNA, the process is called transcription. The transcription takes few steps, the first step is that a specific section of DNA unwinds, exposing one gene. Then alone 1 strand, the complimentary RNA bases bond, at this time, inside of T bonded with A, Uracil will bond with DNA’s Adenine. The enzymes – RNA polymerase will make adjacent nucleotides form covalent bonds and build RNA backbone. Now DNA is released, DNA reforms double helix.

3. How did today’s activity do a good job of modelling the process of RNA transcription? In what ways was our model inaccurate

In today’s activity, I understand how transcription is that make DNA translate into mRNA. The different colour of the back bone makes me have a better understanding of how different DNA and mRNA is. The model is inaccurate because a usual size of DNA which make the mRNA would be much bigger than the only 18 base-pairs that we made in this model.

This photo shows how the mRNA is made

4. Describe the process of translation: initiation, elongation, and termination

Initiation is mRNA binds to small ribosome subunit, then the two ribosome subunits bind together.

Elongation ribosome holds mRNA and allows complimentary tRNA to attach to binding sites, then tRNA binds to P site, another tRNA binds to A site, “empty” tRNA leaves ribosome.

Termination is that the elongation cycle continues until mRNA reads a stop codon.

5. How did today’s activity do a good job of modelling the process of translation? In what ways was our model inaccurate?

Today’s activity let us built a protein through the DNA to mRNA, then finally get protein. The transcription part is not that much because we did it last time, it is more focus on how translation works to make protein. The P site and A site is very clear when I did this activity and helps me understand how everything works. It might be inaccurate if we couldn’t translate the mRNA well and also it is easy to make mistakes that the amino acid is match with the codon on the mRNA strand but not the anticodon.

transection — DNA translate into mRNA

elongation — start with P site

after P site, the A site is also start matching

after A site matched, the A site move to P site and match the A site again

the protein after the whole process (translation), it stops when their is a stop codon.

1. Explain the structure of DNA – use the terms nucleotides, antiparallel strand, and complimentary base pairing.

DNA is also called Deoxyribonucleic acid, it is mand out of sugars, phosphates and nitrogen bases. DNA is a large polymer made of nucleotide monomers that have 2 backbones, which formed by bonded sugar-phosphate portions of adjacent nucleotides. The two strands are antiparallel, one strand will start with sugar, then phosphate, then sugar, the other strand is opposite that start with phosphate, then sugar. Between the two strands, there are many nucleotide bases that make ladders, H-bonds link between base pairs to form complimentary base pairing that made by Pourine and Pyramidine, which are Adenine and Thymine, Guanine and Cytosine.

2. How does this activity help model the structure of DNA? What changes could we make to improve the accuracy of this model? Be detailed and constructive.

By modeling the structure of DNA, we can have a better visual of hoe DNA is look like and by the time we making it, we can be much clearer about the details that we might not know by just reading. For example, when the time me and my groupmates make the DNA, I truly understand how antiparallel strand means, the pink beads that represent the phosphate should be at opposite direction.

To make the model more accurate, we can change the material that we use, maybe use other things to represent the H-bonds that we need to cut ourselves that is hard to keep them same and also when we try to link to strands together, it is easy for them to came apart, especially when it is winding.

3. When does DNA replication occur?

DNA replication occurs before cells divide, it replicates to double cell structures and their genetic information.

4. Name and describe the 3 steps involved in DNA replication. Why does the process occur differently on the “leading” and “lagging” strands?

The three steps involved in DNA replication are unwinding and unzipping, complimentary base pairing and joining. For the first step – unwinding and unzipping, the helix unwinds and unzip, H-bonds between the base pair break. It is caused by DNA helicase. Then the complimentary base pairing is involved by DNA polymerase, which is the new strand will be pairing with the leading strand to form base-pairs that sill A to T and C to G. The last step is Joining, DNA ligase glues the new strands to the leading strand that make a new DNA. Leading strand and lagging strand are different because leading strand continuous as DNA unzips, but the lagging strand is fragments form as DNA unzips DNA ligase glues fragment.

DNA helicase unzip DNA

complimentary base pairing

DNA ligase join the adjacent nucleotides

DNA replication finished (get two DNA)

5. The model today wasn’t a great fit for the process we were exploring. What did you do to model the complimentary base pairing and joining of adjacent nucleotides steps of DNA replication? In what ways was this activity well suited to showing this process? In what ways was it inaccurate?

We use different colour beads to show how the base pair is on the pipe cleaners, twist the white pipe cleaners to join them together. The model we make this time give us a feel of how DNA replicates and how enzymes works in the process, but it is more focus on the leading strand that we didn’t really look at lagging strand and shows how it works in the DNA replication.