Lecture 5: prokaryotes and you

food

Nutritious substance that organisms ingest to maintain life

bacteria

- among the first organisms ever

- nearly everywhere

fermentation

- Biochemical process that gets energy from carbohydrates that does not require oxygen (anaerobic)

- Bacteria and fungi are mostly responsible, often together (SCOBY = symbiotic colony of bacteria and yeast)

Lactic Acid Fermentation

- Takes glucose to make lactic acid

- Done naturally in most organisms to get energy without oxygen

one of the first forms of chemical reactions harnessed by humans

lactic acid fermentation --> early cheesemakers

when do your muscles produce lactate?

as a result of anaerobic metabolism during strenuous exercise

lactic acid in the vagina

maintains PH

common fermenting bacteria

Lactobacillus (lacto = lactic acid)

• creates yogurt, kimchi

foods from lactic acid fermentation

pickles, yogurt, cheese, sour cream, kimchi, sauerkraut

Streptococcus

strep throat

disease

A disorder of structure or function in an organism, especially one that has a known cause and a distinctive group of symptoms

disease is caused by

all forms of organisms (virus, bacteria, fungi, protists, animals, plants)

extracellular bacterial pathogens

- Multiply outside your cells and excrete a substance (toxin) that causes harm

- Cause an imbalance in our microbiome Ex. Clostridium, Staphylococcus, Streptococcus

extracellular bacteria example

Escherichia coli (E. coli)

• Can cause an imbalance in our microbiome

Intracellular bacterial pathogens

- Enter into cells to survive (parasite)

- Can excrete toxins

- Kills your cell by causing it to burst (apoptosis)

intracellular bacteria example

salmonella

where is E. coli found

- raw or u undercooked ground beef

- unpasteurized beverages and dairy

where is salmonella found

- Undercooked eggs, poultry, and meat

- contaminated fruits and vegetables

- Unpasteurized milk and other dairy products

- Reptiles

two types of toxins

endotoxins and exotoxins

endotoxins

- Mostly based on lipids and sugars

- Only released into the host if the bacterial cell ruptures (lysis)

- Can cause septic shock

exotoxins

- Mostly proteins

- Produced and secreted as a defense

- Ex. Botulinum toxin

Antibiotics

Antimicrobial substance active against bacteria

penicillin

antibiotic; increased the life expectancy of humans immensely

microbiomes

-collection of microbes that live in or on your body

- body creates favorable environments for microbes (ex; stomach develops a thick mucus for bacteria to insert in to)

microbiomes and digestion

- responsible for major aspects of digestion (like breakdown of the protein tryptophan

- this makes a molecule called IPA, which protects neurons

leading cause of disease

virus

leading cause of hospitalization

salmonella

how to protect yourself disease

- wash hands

- never drink unpasteurized milk

- take antibiotics only with a bacterial infection and to complete the regimen

- prepare food appropiately

- maintain a healthy gut biome to outcompete pathogenic bacteria (fruits, vegetables, fermented foods)

preparing food safely

- pickling (vinegar kills microbes)

- preservative (high concentration of sugar prevents microbial growth or chemicals)

- canning (heat kills bacteria and then is sealed)

- drying (microbes die without water)

- salting (high salt)

food provided by prokaryotes

soy sauce (fermented soybean paste with many species of bacteria)