Cellular Respiration Activity- Clothespins and Muscle Fatigue

Analysis

1.      My strength declines as I progressed through each trial.

2.      My hands and fingers felt tired and cramped during the end of the trials.

3.      Take in more food before I squeeze the clothespin.

4.      The number of times squeezing the clothespin are usually higher for the dominant hand than the non-dominant hand. We regularly use more of our dominant hands in daily activities, the muscles inside already get used to do so much every day. We have a better control of our dominant hands. However, our non-dominant hands are not trained to do so much normally and therefore easier to get fatigue.

5.      In order to get the energy that we need every day, our bodies oxidise the carbohydrates and the energy carrier ATP releases energy and becomes ADP and Pi. There is not enough energy to supply the hand for this series of continuous events immediately (squeezing the clothespin) and therefore gets fatigue. However, after 10 minutes, our muscles recover as the energy comes back.

A visit to the Royal Ontario Museum

I went to the Royal Ontario Museum on the 28^th October. The ‘tour guide’ in the museum told us a lot of the phenomenon of the population dynamics happening in this world. One of the most remarkable incidents is because of the effect of global warming, the average water temperature increases which lead to the massive breeding of the giant jellyfish in the sea. To us human beings, this is not a very good sign as jellyfish would sting us with their tentacles. Once there were some fishermen in Japan, who threw their nets into the sea and instead of catching fish, they caught a huge amount of giant jellyfish, their weight even exceed the capacity of the boat and the boat turned upside down. Some of the people suggest that in order to eradicate these jellyfish, they should build a net full with steel spikes and tear all of the jellyfish apart, however, it turned out that this is a very bad solution as these giant jellyfish breed a lot when they feel anxious, this causes a lot of their eggs to land on the seabed. The food chain is interconnected, there is always a reason why such an animal exists in this world, disrupting the habitat would surely lead to unimaginable consequences, therefore we should monitor frequently the effect of the activities on the environment.

20-point note

Laws of Thermodynamics

The First Law of Dynamics :

In the universe, the total amount of energy is constant. Energy cannot be created nor destroyed, it is converted from one form to another. If a substance gains a certain amount of energy, there would be a loss of energy in somewhere else in the universe.

The Second Law of Dynamics:

In a closed system, the entropy of the system increases directly or indirectly when there are any changes or remain constant.

The universe favours an increase in entropy.

Reactions

Exothermic reaction/ exergonic reaction

A chemical reaction in which the energy of the reactants is higher than the energy of the products, more energy is released during bond formation than that was absorbed during bond breaking, the products formed is more stable than the reactants, and heat is released.

Endothermic reaction/ endergonic reaction

A chemical reaction in which the energy of the reactants is lower than the energy of the products, less energy is released during bond formation than that was absorbed during bond breaking, heat is required to initiate the reaction as the products formed is less stable than the reactants.

Metabolism

Metabolism equals to the sum of all catabolic and anabolic processes.

Catabolic processes refer to the breaking down of complex structures into simpler ones.

Anabolic processes refer to the formation of complex molecules and structures from simpler ones.

Redox reactions

Redox reactions (oxidation-reduction) refer to chemical reactions in which reduction and oxidation reactions take place at the same time.

A substance undergoes reduction means that it is gaining electrons while a substance undergoing oxidation means that it is losing electrons.

A reducing reagent is one who oxidises itself but reduces others.

An oxidizing reagent is one who reduces itself but oxidises others.

Enzymes

Substrate is the reactant that an enzyme acts on when it catalyses a chemical reaction.

Substrate binds to the specific active sites on the enzyme, the molecule is now called an enzyme-substrate complex.

Enzyme is a dynamic protein molecule that alters its shape to accommodate the substrate, this model of enzyme activity is called induced-fit model.

Coenzymes are organic nonprotein substances that are required for enzymes to work.

Cofactors are nonprotein substances that are required for enzymes to work.

Inhibitors

Competitive inhibitors compete with substrate to bind into the active sites of the enzymes.

Noncompetitive inhibitors bind into other sites of the enzymes, causing an altering of the shape of the enzyme and hence the active sites of the enzyme lose the affinity for its substrate.

Feedback inhibition refers to the metabolic control in cells which the product formed later in the sequence of reaction steps allosterically inhibits an enzyme that catalyses a reaction occurring earlier in the process.

Biotechnology test

Polymerase Chain Reaction

Three steps cycle: heating, cooling, replication

Targeted strand is only heated after the third cycle.

Gel Electrophoresis

digested DNA molecules are injected to the wells

they travel from the negative electrode to the positive electrode

their rate of movement depends on their sizes, with the smaller fragments travelling further and larger DNA fragments nearer to the negative electrode

Restriction Fragment Length Polymorphism

As the amount of DNA is too large and the difference between their sizes are similar, it appear as smear, RFLP is then needed

The next step is Southern blotting to attract the DNA to travel from the gel to the nylon membrane

The nylon membrane is then put in a plastic bag with radioactive probe inside

placed against X-ray film---autoradiography

Vector Cloning

isolate plasmid DNA and select the DNA with the desired gene

insert the desired gene into the plasmid

use the same restriction enzyme to cut the DNAs

DNA ligase is used to fuse them together permanently

put the recombinant plasmid back into the bacteria

clone the bacteria and select bacterias with the desired gene

PCR VS DNA sequencing

PCR starts with a double stranded DNA but DNA sequencing starts with a single-stranded DNA. Both methods require DNA polymerase and nucleotides. PCR require primers but DNA sequencing require radioactively labeled primer and dideoxynucleotides that stop the event of elongation as they do not have a 3’-OH in the structure. PCR is a cycle but DNA sequencing is not. Different form PCR with repetitive heating, cooling and replication, DNA sequencing needs to undergo gel electrophoresis and autoradiography.

PCR VS Vector Cloning

Vector cloning is best for preparing a large quantity of the desired gene, however if the DNA is impure, PCR will then be a quicker method as it does not require cells. PCR can make a lot of copies before vector cloning starts and less time consuming as you do not need to find the desired gene and then clone it. PCR can be used even there is only a small amount of DNA. However, errors will happen during DNA replication, the number of desired copies may not be satisfactory. Vector cloning is a more accurate method.

Deaf by design

After hearing the presentation on deaf by design, I cannot help thinking about the ethical issues brought up by the new generation in the deaf families. I can truly understand that why the deaf people are so eager to find a spouse and give birth to deaf children, in which they can find likeliness of each other. However I am strongly against them to abore fetus without listening disabilities, it is just that they are different from their family members do not mean they do not have the right to live. In addition, they are the ones who are regarded as normal by the general public. On the other hand, I really feel enraged when the parents actually persuade their child not to have cochlear implant and knock down their child’s confidence. If it is the will of the child to have the opportunity to listen to the wonderful voices in the world, why don’t give her a chance of the parents are able to do so. The child should have the right to choose the pathway of her own future.

Genetics Test

DNA Replication

DNA polymerase III catalyses the elongation of new DNA at a replication fork

DNA strands grows form 5’ to 3’ direction

Leading strand- copied into the direction of the fork continuously from a single primer

Lagging strand- copied away from the fork in short segments called Okazaki fragments, each requiring a new primer

                                                                  DNA Transcription

Transcription: initiation, elongation and termination

Transcription factors recognizes the 5’ TATA 3’ box

Terminator sequence AAUAA

A 5’ cap is at the 5’ end of the pre-mRNA molecule

A poly(A) tail is at the 3’ end

                                                                 DNA Translocation

mRNA is read from 5’ to 3’ codon by codon

The P site on ribosome holds the tRNA with the polypeptide chain

The A site has the tRNA with the next amino acid

It is at the E site where tRNA is discharged