- Mix 2cm3 of lactase enzyme with 8cm3 of 2% sodium alginate solution in a 15cm3 beaker.
- Add the alginate enzyme mixture to 20cm3 1.5% calcium chloride solution in 50cm3 beaker. Do this one-drop at a time. This will produce little beads immobilizing the lactase enzyme.
- Leave the beads to harden in the solution for 10 minutes.
- After ten minutes separate the beads from the calcium chloride solution through a tea strainer.
- Attach a piece of tubing (4mm diameter aquarium airline tubing 10cm in length) to the end of the 10cm3 column syringe barrel.
- Place a piece of nylon gauze (1cm2) at the bottom of the column that has been made from the 10cm3 syringe barrel.
- Attach the tap 5cm down the tubing of the 10cm3 syringe barrel. Do not make the tap so tight that the milk will not be able to pass through.
- Place a 50cm3 beaker underneath the end of the tube (this will collect the milk)
- Pack the beads into the column made from the syringe barrel.
- Pour the ordinary milk containing lactose into the column. The trapped lactase enzyme splits the lactose sugar; glucose and galactose are then formed.
- Detect whether the milk has glucose or not using a glucose test strip. Dip the strip into the milk that has been through the syringe with the beads. Once the glucose strip has been dipped into the milk hold the piece of paper up to the box to compare colours.
0 Comments
The relationship between smoking and the death rate as a consequence of smoking is a positive correlation. This means that as one factor increases i.e. smoking the other simultaneously increases i.e. the death rate due to cancer. Many reports and surveys support the fact that smoking causes cancer; it is not another unknown factor which causes cancer. It is the tobacco. Tobacco smoke consists of over 7,000 chemicals of which 70 of them are known to cause cancer. Smoking accounts for 30% of cancer deaths in the United States. Not only this but also 87% of deaths due to lung cancer in men and 70% in women. One of the first studies that supports this idea that tobacco and smoking causes cancer was in the 1950s by two cancer researchers, E Cuyler Hammond, PhD and Daniel Horn PhD. They did what is called a cohort study. In January 1952 Hammond and Horn had roughly 188,000 men who volunteered to take part in this research. The participants gave their smoking background, how often they smoked, when they started, how many cigarettes they smoked and all of their current and previous habits. In November 1952 it was inquired which participants were alive/dead/don't-know. 20 months after this Hammond and Horn had discovered preliminary findings which were soon published on the 7th August 1954. The conclusion from this investigation was that men who smoked cigarettes had a far higher death rate than men who had never smoked cigarettes or only smoked cigars and pipes. This study was one of the first to provide real evidence that tobacco is a causation of cancer and not another factor. References http://ije.oxfordjournals.org/content/38/5/1175.full http://www.cancer.org/cancer/cancercauses/tobaccocancer/questionsaboutsmokingtobaccoandhealth/questions-about-smoking-tobacco-and-health-cancer-and-health http://www.cancer.org/research/acsresearchupdates/the-study-that-helped-spur-the-us-stop-smoking-movement OXFORD IB DIPLOMA PROGRAMME BIOLOGY COURSE COMPANION 2014 EDITION ANDREW ALLOTT, DAVID MINDORFF Not everyone loves a gouda bit of cheese but it is estimated that the average american consumes approximately 16kgs of cheese every year. Having a cheesy pizza or toastie probably leaves you wanting more. You may think that it is because of the taste of the cheese however there is more to the addiction of cheese than just the taste. Casein is a protein that is found in milk, meaning it is also found in cheese. 'Ceasus' in latin translates to cheese. Casein releases casomorphins which control pain, reward and addiction. This release of casomorphins triggers a high level of dopamine, a neurotransmitter which gives the brain a pleasurable reward. So, in conclusion when we eat cheese our dopamine levels rise making cheese addictive because of the effect it has not only on our tastebuds but also on our brains. http://www.ncbi.nlm.nih.gov/pubmed/25692302 Stargardt’s disease is the slow but progressive vision loss due to the death of photoreceptor cells in the macula (the central part of the retina). Stem cells can be used to help treat Stargardt’s disease as they are undifferentiated and have the ability to become any specialised cell. Not only are stem cells special in this sense but also in the fact that they are able to divide continuously whereas differentiated cells can no longer divide. Due to this ability, stem cells may be able to help Stargardt’s disease by being taken from the embryo and cultured in the lab to become retina cells. These specialised cells would then be transplanted into the eye of someone with Stargardt’s disease thus repairing their eyesight. Although this stem cell procedure from taking the cells from an embryo could be extremely effective and help many people it also has its ethical issues. The controversy lays between two main ideas/points, prevention of suffering, and the duty to respect human life. This causes disagreement because it can be argued when life begins, many people say life begins when the sperm and egg first “join together” thus meaning taking cells would be destroying human life. Whereas many people say life has not yet begun as the embryo does not have emotional, psychological or physical features that a human would. The argument lays beneath the question as to when does human life begin. Another disease which can be treated with the use of stem cells is sickle cell disease, this is a hereditary form of anaemia. The red blood cells that carry oxygen become mutated thus making them a crescent like shape. As a consequence of their shape it means that the red blood cells cannot move around the body as well, the sickle shape often causes blockages of blood vessels which have negative effects, for example tissue and organ damage. Stem cells can be taken from the bone marrow of a person who does not have sick cell disease and can be transplanted into the bone marrow of the person with the disease. The ethical issues of bone marrow transplant are that it causes a lot of pain and suffering for the person providing the stem cells for the transplant, the procedure is very long and it can be argued whether it is right to lower the quality of life for that person in order to conserve and preserve someone else’s life. Many people argue that it may be in the way of God or against nature as well. |
Professor Laura M TotterdellPhD in physiology and cake making as well as quantum physics. Archives
April 2016
Categories |