Chemists and how they have made an impact on our lives

Louis Pasteur

• was born on December 27,
  1822

• An average student, _____ was skilled at drawing and painting.

Louis Pasteur

• discovered that microbes were responsible for souring alcohol and came up with the process of pasteurization.

Fermentation

is a biological process in which microorganisms, such as yeast or bacteria, break down sugars to produce energy and form products such as alcohol, acids, and gases.

sugar

yeast/bacteria

• _____→ _____/_____ → New substances are produced

1. 1800s-1850s

2. 1854

3. 1855

4. 1864

Pasteur's Breakthroughs: A Timelinechallenge

1800s-1850s

Louis' explained fermentation scientifically

1800s-1850s

Pasteur showed that fermentation is associated with living microorganisms, particularly yeast, and that different microorganisms are responsible for different types of fermentation.

1854

Louis becomes a professor of science

1854

• Pasteur was appointed professor of chemistry and dean of the science faculty at the University of Lille.

• and one of his duties included finding scientific solutions to common problems in the area.

1855

Louis finds bacteria in the drink

1855

• Louis was assigned the job of figuring out why common drinks like beer and wine became sour.

• He discovered the bacteria growing in the drinks and figured out that if you boiled the drinks and then cooled them, it killed the bacteria.

1864

He studies where the bacteria came from

1864

• went on to study where the bacteria growing in food and drinks were coming from, and he finally figured out it came from the air or environment

Pasteurization

Pasteur heated wine and milk to a certain temperature, then cooled it. He observed that the harmful germs were killed but the taste stayed almost the same.

Pasteurization

This process, called _____, keeps food and drinks safe and fresh.

Spontaneous Generation

The idea that bacteria and tiny organisms could just appear out of nowhere.

• Long ago, people thought that maggots (baby flies) appeared out of nowhere from rotting meat.

Louis Pasteur Swan Neck Experiment

Louis Pasteur used a special flask whose neck was shaped like an S or the neck of a swan

Louis Pasteur Swan Neck Expirement

Louis Pasteur discovered that germs in food and drinks don't just appear on their own. They come from the air, dust, and surroundings.

1865

Louis saves the silkworms

Silkworm Disease Experiment

He found tiny spores (particles) in the sick animals that were not present in healthy ones.

Mothers who carried the spores often produced infected eggs and infected offspring - showing the disease could be passed from one generation to the next.

Pasteur's methods saved the French silk industry by preventing mass deaths of silkworms.

1. Microscopic screening for moths and eggs

2. Select only the healthy breeders

3. Separate and destroy the infected stock

4. Improve hygiene and rearing practices

Silkworm Disease Experiment

How he fixed the problem:

1879

Louis’ discovers vaccinations for chickens

Pasteurella Multocida

The bacteria that caused chicken cholera.

Fresh Germ Experiment

the "fresh germs" were live, strong bacteria that cause the disease called chicken

cholera,

taken directly from the blood or droppings of sick chickens. collect the germs and grow them in special containers (called culture flasks)

"Aged germ" - exposed to air for too long and weak

1855

A vaccination for rabies

1. Studied rabies in animals

2. Made the germs weaker

3. Tested a safe series of vaccines

What Pasteur did? (1885)