GS CHEMISTS AND HOW THEY HAVE MADE AN IMPACT ON OUR LIVES

Louis Pasteur (1822-1895), French scientist, chemistry, biology, microbiology, medicine, agriculture, food science.

— was a — whose work connected —, —, —, —, —-, and —.

chemist, chemical investigations, biology, medicine

Pasteur began his career primarily as a —-, but his — eventually led him into — and —.

Chemistry →Fermentation →Microorganisms →Germ Theory →Disease Prevention → Vaccination

Pasteur’s scientific journey can be summarized as:

Institut Pasteur, progression, crystal chemistry, fermentation, microbiology, vaccination.

The — describes his work as a — from — to —, —, and —.

1847-1850s

1857

1859-1864

1863-1865

1865-1869

1878

1878

1881

1885

1887

1895

TIMELINE OF PASTEUR'S CONTRIBUTIONS (YEARS)

Research on molecular asymmetry and crystals

1847-1850s

Major studies of fermentation

1857

Experiments challenging spontaneous generation

1859-1864

Research on wine and preservation

1863-1865

Research on silkworm diseases

1865-1869

Germ theory and infectious disease research

1878

Fowl cholera vaccination experiments

1878

Anthrax vaccine

1881

Rabies vaccine/treatment

1885

Institut Pasteur established

1887

Pasteur died, leaving a major scientific legacy

1895

1847: MOLECULAR ASYMMETRY, tartaric acid crystals

Pasteur studied —.

1847: MOLECULAR ASYMMETRY, chemical composition, three-dimensional arrangement

He discovered that certain crystals had the same — but differed in their —.

1847: MOLECULAR ASYMMETRY, polarized light

Some crystals behaved differently when exposed to —-.

same types of atoms

same numbers of atoms

different spatial arrangements

Two molecules can have:

1847: MOLECULAR ASYMMETRY, stereochemistry

This helped establish the foundations of —-, the study of the three-dimensional arrangement of atoms in molecules.

chemistry, stereochemistry

WHY DOES MOLECULAR ASYMMETRY MATTER TODAY?

Pasteur's early work in — contributed to the development of —.

how substances interact with biological molecules

chemical reactions

pharmaceutical activity

properties of materials

Molecular shape can affect:

Two molecules may contain the same atoms but have different arrangements.

One arrangement may interact effectively with a biological target, while another may interact differently.

Examples of Molecular Asymmetry

Chemistry

—- is not only about what atoms are present; it is also about how those atoms are arranged.

1857: PASTEUR AND FERMENTATION

Pasteur investigated why some industries producing wine, beer, vinegar, and other fermented products were experiencing problems with spoilage.

1857: PASTEUR AND FERMENTATION, fermentation

He discovered and demonstrated that —- was associated with the activity of living microorganisms.

1857: PASTEUR AND FERMENTATION, microorganisms, fermentation

Different — could be associated with different — processes.

Lactic acid: Bacteria turn sugars into lactic acid. This makes food taste sour or tangy.

Alcoholic: Yeast turns sugars into alcohol and carbon dioxide gas.

Acetic acid: Bacteria turn alcohol into vinegar

Examples of different microorganisms could be associated with different fermentation processes

Fermentation, biochemical, microorganisms, sugars

— is a — process in which — transform substances such as — into other products.

ALCOHOLIC FERMENTATION

Example of fermentation

Yeast breaks down sugars such as glucose and produces ethanol and carbon dioxide:

Glucose →Ethanol + Carbon dioxide

ALCOHOLIC FERMENTATION

fermentation

Pasteur's work showed that — was associated with the activity of specific living microorganisms.

FERMENTATION, microbiology, biochemistry, food spoilage, disease

This was a major step toward understanding — and — and eventually helped scientists understand how microorganisms can also contribute to — and —.

spontaneous generation

During Pasteur's time, some scientists supported the idea of —.

SPONTANEOUS GENERATION

It was an old scientific idea that living organisms could arise naturally from nonliving matter.

SPONTANEOUS GENERATION

In simple terms, people once believed that life could appear without coming from another living organism.

People observed things like:

Maggots appearing on rotting meat.

Microorganisms appearing in broth.

Mice supposedly appearing from stored grain or dirty materials.

EXAMPLES OF SPONTANEOUS GENERATION

SPONTANEOUS GENERATION

They could see the organisms, but they did not know that microscopic organisms or eggs were already present and could not be seen with the naked eye.

"Do microorganisms appear spontaneously, or do they come from microorganisms already present in the environment?"

Pasteur wanted to answer an important question:

Pasteur placed nutrient-rich liquid in special swan-neck flasks.

1. The liquid was heated.

2. Heating killed microorganisms present in the liquid.

3. The curved neck allowed air to enter.

4. Dust and microorganisms from the air became trapped in the bend.

5. The liquid remained free from microbial growth while contamination was prevented.

6. When the liquid was exposed to trapped contaminants, microbial growth could occur.

PASTEUR'S SWAN-NECK FLASK EXPERIMENT

Heat applied —> Let flask sit —> No bacteria present

PASTEUR'S SWAN-NECK FLASK EXPERIMENT (1)

Heat applied —> Remove the neck and let it sit —> Bacteria present

PASTEUR'S SWAN-NECK FLASK EXPERIMENT (2)

Heat applied —> Tilt flask sideways and let it sit —> Bacteria present

PASTEUR'S SWAN-NECK FLASK EXPERIMENT (3)

PASTEUR'S SWAN-NECK FLASK EXPERIMENT

It provided strong experimental evidence against spontaneous generation and supported the idea that microorganisms are present in the environment.

PASTEUR'S SWAN-NECK FLASK EXPERIMENT, existing microorganisms, environmental contamination

This changed their old belief that spoilage or microbial growth might happen spontaneously; instead, microorganisms come from — and —.

PASTEUR'S SWAN-NECK FLASK EXPERIMENT, infectious disease

If microorganisms can contaminate food and laboratory materials, they can also cause —.

modern microbiology, infection control

Pasteur’s Swan-Neck Flask Experiment helped establish the scientific foundation for — and —.

wine, PASTEURIZATION

Pasteur investigated why — sometimes became spoiled. He discovered that microorganisms could cause undesirable chemical changes in wine and other products. He used controlled heating to reduce harmful or unwanted microorganisms while preserving the product's useful qualities. This process became known as —.

Pasteurization

— is a controlled heat treatment used to reduce microorganisms in certain foods and beverages.

False

Pasteurization is the same as sterilization. True or False

Pasteurization, Sterilization

— greatly reduces microorganisms to improve safety and shelf life, while — aims to eliminate all viable microorganisms.

Pasteurization

— works by heating a food or beverage to a carefully controlled temperature for a specific amount of time, then cooling it.

Pasteurization, heat

The — reduces microorganisms that can cause disease or spoilage.

FOOD OR BEVERAGE CONTAINS MICROORGANISMS

CONTROLLED HEATING

MICROORGANISMS ARE REDUCED

RAPID COOLING

PROPER STORAGE

PASTEURIZATION PROCESS

FOOD OR BEVERAGE CONTAINS MICROORGANISMS

Milk, for example, may naturally contain bacteria from the environment.

CONTROLLED HEATING

The product is heated to a specified temperature for a specified time. The exact temperature-time combination depends on the product and processing method.

MICROORGANISMS ARE REDUCED

Heat damages important structures and processes inside microorganisms, particularly their proteins and cellular systems. Many microorganisms are killed or become unable to reproduce.

RAPID COOLING

The product is cooled to slow the growth of microorganisms that may remain.

PROPER STORAGE

The pasteurized product is packaged and stored appropriately, often under refrigeration.

No

DOES PASTEURIZATION KILL EVERYTHING?

True

Pasteurization does not sterilize a product. Some microorganisms may survive, which is why pasteurized foods may still require refrigeration and proper handling. True or False

wine, fermentation, microorganisms, fermented products

Pasteur discovered through his studies of — and — that — were responsible for undesirable changes in —. This led to the development of controlled heating as a way to reduce these microorganisms.

False

Pasteurization simply "cook" food. True or False

Pasteurization

It is a carefully controlled heat treatment designed to reduce microorganisms while preserving the quality of the product as much as possible.

1860s, France's silk industry, silkworms, French government

In the —, — was experiencing a major crisis because — were dying from disease. The — asked Louis Pasteur to investigate the problem.

Healthy silkworms vs. Diseased silkworms, microscopic observations, controlled experiments

He used — and — to determine how disease was transmitted.

Healthy silkworms vs. Diseased silkworms, diseased breeding stock, pebrine, infected eggs

One important finding was that — could transmit — to the next generation through —.

germ theory of disease

Because Pasteur's work on silkworm diseases came during the period when scientists were developing a better understanding of microorganisms and infectious diseases. This contributed to the development and acceptance of the —.

GERM THEORY OF DISEASE

It explains that specific microorganisms can cause specific infectious diseases.

medicine, public health

Germ theory transformed — and —.

True

Once scientists understood that microorganisms could cause disease, they could develop ways to control them. True or False

Hand hygiene

Sterilization

Disinfection

Vaccination

Food safety

Infection control

Ways to control microorganisms that cause diseases

Hand hygiene

Washing hands helps remove microorganisms and reduce their transmission.

Sterilization

Medical instruments can be treated to eliminate microorganisms before use.

Disinfection - Disinfectants

It can reduce microorganisms on appropriate surfaces.

Vaccination - Vaccines

Prepare the immune system to recognize specific infectious agents or their components.

Food safety

Processes such as pasteurization reduce microorganisms in certain foods and beverages.

Infection control

Hospitals use procedures designed to prevent microorganisms from spreading between patients, healthcare workers, and environments.

Vaccination

Pasteur developed an important method for creating protection against certain infectious diseases by using weakened/attenuated forms of disease-causing microorganisms, what is it?

Vaccination

It is a method of preparing the immune system to recognize and respond more effectively to a particular infectious disease.

modern immunology

Vaccination contributed to the development of —- and vaccination.

Fowl cholera

Anthrax

Rabies

MAJOR EXAMPLES OF VACCINATIONS

ATTENUATION

PASTEUR'S IMPORTANT DISCOVERY:

Attenuation

It means weakening a microorganism so that it has reduced ability to cause disease while retaining the ability to stimulate protective immunity.

Attenuation

This was an important development because it showed that microorganism did not necessarily have to cause severe disease to stimulate protection.

FOWL CHOLERA VACCINE, late 1870s, colleagues, fowl cholera, chickens

In the —, Pasteur and his — studied —, a disease affecting —.

FOWL CHOLERA VACCINE, old culture of the disease-causing organism

They observed an important phenomenon involving an —.

The microorganism had become attenuated under certain conditions.

This led to an important principle: A weakened microorganism can sometimes stimulate protection against a more dangerous form of the disease.

What did Pasteur learn in Fowl Cholera Vaccine?

Fresh culture of cholera bacterium —^injection→ Chicken injected with aged culture is chicken free from cholera

↓injection

Normal healthy chicken is dead due to cholera

The classic experiment of Pasteur with chicken (fowl) cholera

attenuation, anthrax

Pasteur then applied the idea of — to —, a serious disease affecting livestock and humans.

1881, collaborators, Pouilly-le-Fort experiment

In —, Pasteur and his — conducted the famous —.

Pouilly-le-Fort experiment

They simplified experiments with vaccinated sheep and unvaccinated sheep.

Pouilly-le-Fort experiment

Both groups were subsequently exposed to anthrax.

Pouilly-le-Fort experiment

The result was that vaccinated animals were protected much more effectively than unvaccinated animals.

Pouilly-le-Fort experiment

This demonstrated that vaccination could be used as a practical method to protect animals from infectious diseases.

Explain the Pouilly-le-Fort experiment

rabies

Pasteur's most famous vaccination work involved —.

Rabies

A serious viral disease that affects the nervous system.

collaborators, rabies

Pasteur and his — developed a series of preparations used to confer protection against — after exposure.