Cellulose and Starch Glycogen Sugar storage form in

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Cellulose and Starch

Cellulose and Starch

Glycogen • Sugar storage form in animals • Large stores in muscle and liver

Glycogen • Sugar storage form in animals • Large stores in muscle and liver cells • When blood sugar decreases, liver cells degrade glycogen, release glucose

Fredrick Griffith

Fredrick Griffith

Streptococcus pneumoniae

Streptococcus pneumoniae

Fig. 6. 3 b

Fig. 6. 3 b

Fig. 6. 3 b

Fig. 6. 3 b

Fig. 6. 3 b

Fig. 6. 3 b

Fig. 6. 3 b

Fig. 6. 3 b

Avery, Mc. Carty and Mac. Loed, 1944

Avery, Mc. Carty and Mac. Loed, 1944

Avery, Mc. Carty and Mac. Loed, 1944

Avery, Mc. Carty and Mac. Loed, 1944

- double ring - single ring

- double ring - single ring

Watson, Crick and Wilkins 1962 Nobel Prize for Physiology or Medicine

Watson, Crick and Wilkins 1962 Nobel Prize for Physiology or Medicine

1886: Christiaan Eijkman and two other Dutch doctors set sail for the island nation

1886: Christiaan Eijkman and two other Dutch doctors set sail for the island nation of Java (now part of Indonesia). Java was part of the Dutch East Indies, an important trading colony for the Dutch. In the 1800’s epidemics off malaria, cholrera, dysentery and beri were common and costly.

The Dutch government sent Dr. Eijkman to find a cure for beri which was

The Dutch government sent Dr. Eijkman to find a cure for beri which was effecting navy crews and the native workforce. In Sinhalese, beri means weak, and doubling the word intensifies the meaning Beriberi results in weight loss, muscle weakness and loss of feeling in limbs leading to paralysis.

Beriberi can also lead to edema (swelling) of the legs and an enlarged heart

Beriberi can also lead to edema (swelling) of the legs and an enlarged heart as the heart tries to compensate resulting in heart failure. Beriberi is common in end-stage alcoholics.

What may have caused the beri epidemic?

What may have caused the beri epidemic?

Eijkman and his colleagues had spent the previous few months in the lab of

Eijkman and his colleagues had spent the previous few months in the lab of Robert Koch a German physician and the one the father’s of Germ Theory – the idea that microscopic organisms could cause disease. In Koch’s lab they learned to isolate and identify bacteria on petri plates. By mid-1887 the group completed their work and filed their report. They confirmed that a bacterium caused beri but they were unable to successfully infect another organism.

Furthermore, unlikely most infectious diseases, beri appeared require repeated exposure in the area where

Furthermore, unlikely most infectious diseases, beri appeared require repeated exposure in the area where beri was common. The group left Eijkman on Java as head of the medical school where he continued to research beri. Over the next three years he failed to isolate the beri bacterium. In 1890 he made the chance discovery that the chickens in the hospital yards had the same symptoms as those of beri.

What would you have done with this new information?

What would you have done with this new information?

Eijkman moved the chickens from the hospital yard to cages in a lab. Miraculously,

Eijkman moved the chickens from the hospital yard to cages in a lab. Miraculously, the chickens recovered with no apparent intervention! Eijkman began to search for cause of the rapid recovery and possible cure to beri. He discovered that the chickens diet had changed from left-over polished, white rice from the officer’s mess to unpolished, brown rice.

What hypothesis(es) could be generated from Eijkman’s observations?

What hypothesis(es) could be generated from Eijkman’s observations?

Eijkman conducted a number of experiments and discovered: 1) that chickens fed only white

Eijkman conducted a number of experiments and discovered: 1) that chickens fed only white rice soon developed the symptoms of beri. 2) When fed unpolished, brown rice or even just the polishings of rice they soon recovered. 3) Chickens fed solely on brown rice never developed beri symptoms.

Eijkman wondered whether the same results would apply to people. But controlling peoples diets

Eijkman wondered whether the same results would apply to people. But controlling peoples diets is difficult and expensive. But there was one place where people’s diets could be controlled – Prison. Eijkman, along with the Javanese supervisor of Civil Health, A. G. Vorderman, began looking at the diet of prisoners and the prevalence of beri in prisons throughout Java.

No. of prisons with beri present Brown rice 35 1 Mixed brown rice &

No. of prisons with beri present Brown rice 35 1 Mixed brown rice & white rice 13 6 White rice only 51 36 Diet Percentage of prisons with beri present 2. 7% 46. 1% 70. 6%

What are some alternative hypotheses that could explain these prison results?

What are some alternative hypotheses that could explain these prison results?

Vorderman consider alternative sources for the beri bacterium. For example, No. of prisons with

Vorderman consider alternative sources for the beri bacterium. For example, No. of prisons with beri present Percentage of prisons with beri present 40 -100 26 13 50. 0% 21 -40 32 11 34. 4% 2 -10 42 19 45. 2% sparse 73 32 44. 6% medium 1 1 N/A* overcrowded 26 9 34. 6% Age of Bldgs. Population Density

Eijkman left java in 1890 and over the next few years extracted the curative

Eijkman left java in 1890 and over the next few years extracted the curative factor from rice polishings using water and alcohol; demonstrated that the factor was destroyed at 120 C and could cross a cell membrane.

Not long after English researcher Fredrick Hopkins discovered that rats fed a strict diet

Not long after English researcher Fredrick Hopkins discovered that rats fed a strict diet of only the major macromolecules: proteins, fats and carbohydrates plus water and salts developed symptoms similar to beri. But as little as 2 ml of milk a day could reverse the symptoms. Like the rice polishings there was a factor present in milk that cured beri.

At virtually the same time other researchers such as Casimir Funk in England Umetaro

At virtually the same time other researchers such as Casimir Funk in England Umetaro Suzuki in Japan were isolating other sources of the antiberi factor, as well as factors that cured a number of other diseases. Slowly it began to dawn on scientists and doctors that diseases such as beri were not the result of a bacterium but rather the absence of something in the diet – something that Casimir Funk called ‘vital amines’. What was the anti-beri factor that Eijkman and others had discovered? https: //www. nobelprize. org/prizes/lists/all-nobel-prizes/