The Effects of Chemicals on Living

Organisms

CO: SWBAT describe the role of

biotechnology in daily life.

LO: SWBAT write a letter about the ethical

implications of humans’ ability to change and

manipulate DNA.

CO: SWBAT describe the beneficial effects of

chemicals on living organisms.

LO: SWBAT calculate lethal dose amounts

with relation to the body mass of different

organisms.

Imagine you are hiking with your friend. You

stop by a stream and take a sip of water.

“Water tastes so much better without any

chemicals in it!” exclaims your friend.

Is the water from the stream truly free of

chemicals?

Water itself is a chemical.

A chemical is any substance that has a

defined composition.

The stream’s water probably contains other

chemicals

Dissolved minerals

Gases

You are surrounded by chemicals everywhere

you go.

Even your body is made of chemicals!

Natural chemicals are chemicals that can be

found in nature or that are made by natural

processes.

Water

Rocks

Plants

Citric acid gives

oranges their tart

taste.

Fructose is a sugar that

is commonly found in

fruits.

Water makes up a large

part of all plants and

animals.

Natural chemicals are made by the human

body through natural processes

Breathing – release carbon dioxide

Proteins and fats

Made by other living things

Plants - carbohydrates

Insects

Bacteria

Minerals and gems form through processes

involving the Earth

A chemical that is not found in nature and

that is not made by natural processes

Plastics

Medicines – pain relievers

Food additives – preservatives, food coloring

Clothing - polyester

Made during chemical reactions between

natural chemicals, other synthetic chemicals,

or both

Developed through lab experiments

Oftentimes produced by accident

Teflon

Silly putty

A medicine is a substance that is used to

cure, prevent, or treat illness or discomfort.

Made of one chemical or a mixture of chemicals

Improve a person’s health or well-being by

causing a change in the person’s physical or

psychological state

Some are natural chemicals, but many are

synthetic

Natural – penicillin

Synthetic - aspirin

Kind Example Effect

Analgesic Acetaminophen It relieves pain.

Antihistamine Diphenhydramine It helps relieve minor

allergy symptoms.

Antacid Aluminum hydroxide It neutralizes stomach

acid for relief from

heartburn.

Antibiotic Penicillin It kills some kinds of

bacteria to help cure

infections.

Hormone Insulin Insulin helps treat

diabetes.

Vaccine Chickenpox vaccine It helps prevent infections

in people exposed to the

disease.

To be a good medicine, a medicine must be

potent.

Potency is the power of a medicine to produce its

desired effect

A good medicine must be safe; however, no

medicine is perfectly safe for everyone.

Side effects are effects that differ from the

intended effect.

A dose is the amount of medicine that needs

to be taken at one time.

Depends on who is taking the medication

Adults needs a larger dose than children

Depends on the size of the person

Larger people need a larger dose to have the correct

concentration of medicine in their bodies

Concentration refers to the amount of a substance

in a given volume

A chemical that can prevent or slow down

the spoiling of food

Useful because they keep food fresh during the

time it takes to transport the food to stores

Allow you to store foods for longer periods of

time and keep foods safe to eat

Some prevent the growth of bacteria or mold

Antibiotics can be added to poultry, fish, or canned

goods to kill bacteria

Sorbic acid can be added to fruit juice or dried fruit

to prevent the growth of mold

Some prevent chemical reactions that break

down foods

BHA and BHT are added to foods such as margarine

and cereals to prevent the foods from becoming

rancid

Vitamin C can be added to fruits to prevent a

chemical reaction that causes the fruits to turn brown

Some prevent foods from going stale

Farmers use different chemicals to increase

the amounts of fruits or vegetables that are

grown on a given amount of land.

Fertilizers

A chemical that improves the quality of the soil to

produce plants

A mixture of nitrogen, phosphorus, and potassium that

are the most important elements for plant growth

Pesticides

A poison that is used to kill insects, weeds, and other

crop pests

10 billion kilograms of pesticides used yearly

worldwide

The practice of providing sewage and solid

waste disposal, clean drinking water, and

clean living conditions

Good sanitation helps to prevent the spread

of diseases and infections.

Chlorine is used in the treatment of sewage wastewater Drinking-Water Treatment

First filtration – filtered to remove large organisms and trash

Coagulation – alum is mixed in and forms sticky globs, causing bacteria to cling to the globs

Second filtration – layers of sand, gravel, and hard coal filter the remaining impurities

Chlorination – chlorine is added to prevent bacteria from growing in the water

Aeration – air is forced through the water to release unwanted gases, which reduces odor and improves taste

Additional treatment –

fluoride may be added to prevent tooth decay

Sodium compounds or lime may be added to soften hard water

Chemicals in household cleaners are needed

to kill bacteria and other disease-causing

microorganisms

Bleach is a common name for the chemical

sodium hypochlorite and is effective at killing

bacteria and viruses

Hydrogen peroxide can be applied to wounds to

prevent infection

Problems resulting from dangerous chemicals

depend on a person’s exposure to the

chemicals

Exposure to a chemical means being in contact

with the chemical

Greater exposure = greater risks

Exposed to chemicals through

Inhalation

Ingestion

Absorption

A person’s risk of being affected negatively

by something dangerous

Depends on the physical and genetic make-

up of the organism

Cancer

A disease caused by uncontrolled cell growth

Substances that cause cancer are called

carcinogens

Carcinogen Affected body parts

Asbestos Lung, colon, larynx, and GI system

Alcohol Mouth, pharynx, larynx, esophagus, liver,

and breast

Arsenic Skin, lung, kidney, liver, and GI system

Benzene Bone marrow

Coal tar Lung, mouth, skin, stomach, larynx,

bladder, and bone marrow

Radon lung

Soots Lung, esophagus, liver, and bone marrow

Secondhand smoke Lung

Smokeless tobacco mouth

Tobacco smoke Lung, bladder, mouth, pharynx, larynx,

esophagus, and pancreas

A disease in which a person’s immune system

attacks certain cells, tissues, or organs of the

body

For example, lupus is an autoimmune disease

that may be triggered by certain antibiotics,

certain drugs, and hormones

Some are caused when a fetus is exposed to

certain chemicals

Fetal Alcohol Syndrome (FAS)

A group of defects that a child may have because the

mother drank large quantities of alcohol while

pregnant

Small birth weight

Brain damage

Mental retardation

Thalidomide (a sedative) and isotretinoin

(acne medication) have been known to cause

birth defects

A disease that affects the body’s ability to

use sugar for energy

Can be triggered by steroid medications used

to treat asthma and arthritis

People believe diabetes can be triggered by

vaccines (no scientific proof)

Can be caused by chemical exposure

Lead poisoning

Children eat paint chips from walls painted with lead-

based paints

Hinders the body’s neurological development

Causes speech delays, ADHD, ADD

Pain relievers can cause kidney damage if

they are used for long periods of time

Combinations of aspirin, acetaminophen, and

caffeine can damage kidneys

Exposure to cigarette smoke can contribute

to the development of heart disease

Taking illegal drugs, like cocaine and Ecstasy,

can cause heart attacks

A disease that causes air passages in the

lungs to narrow

Symptoms include shortness of breath,

wheezing, and coughing

Can be caused by chemicals in the air

Cigarette smoke

Air pollutants

Aerosol sprays

Laws and rules to reduce exposure

Clean Air Act (1970, 1990)

Clean Water Act (1972)

These acts set standards for acceptable levels of

pollutants in the air and water

Rules that ban smoking

Personal

Make good choice

Work in well-ventilated area when using

chemicals

Thoroughly wash produce