The Human Body A. Life and Chemistry
1. A chemical ……………………………. is the process that occurs when
compounds, called reactants, form one or more new substances, called products.
2. During a chemical reaction, bonds are ……………………………….. and new bonds
are formed.
3. Chemical reactions take place in the body’s ………………………………………. and are
essential for human life.
B. Elements and Compounds
1. ………………………….. are the basic units that make up chemicals.
a. Elements cannot be broken down or transformed into another element during
a(n) ……………………………………….. reaction.
b. Six elements—……………………………….., oxygen, hydrogen, nitrogen, calcium,
and phosphorus—make up …………………………………... percent of the body’s mass.
2. …………………………………….. are made of two or more elements and can be broken
down into simpler substances.
3. Compounds are made by binding ………………………………... together in different
ways.
a. …………………………………..bonds form when electrons travel from one element
to another.
b. ………………………………. bonds form when the electrons in each element are
shared.
4. …………………………….. compounds do not contain carbon-hydrogen bonds.
a. ……………………………….. gas and water are inorganic compounds that humans
need to survive.
b. A substance that gives up or gains an electron is called a(n) ………………………………………………..
c. ………………………………... ions help nerve and muscle cells function and make
up bone.
d. Water is able to dissolve many substances because of……………………………………
its .

Name Date Class

Lesson Outline continued

5. In science, the term …………………………………... describes compounds that contain
carbon and other elements, such as hydrogen, oxygen, phosphorus, nitrogen, or sulfur, held together by covalent bonds.
6. Substances that form from joining many small organic compounds
are called ………………………………………..
a. Carbohydrates are formed when simple sugars, called
……………………………………….., are joined together.
b. …………………………………….. are made from carbon, hydrogen, and oxygen and
include cholesterol and triglycerides.
c. Proteins form when …………………………………., the building blocks of protein,
join together.
d. Nucleic acids are formed when …………………………………………., molecules made
of a nitrogen base, a sugar, and a phosphate group, join together.
C. The Body’s Organization
1. ………………………………………... that are organized in specific locations help cells carry
out specific functions.
2. ……………………………………...are the building blocks of all living things and have
different shapes and functions.
3. ………………………………….. are made of a group of cells that work together
and perform a function.
4. A(n) ……………………………………..., such as a liver or spleen, is a group of tissues
that work together and perform a function.
5. Organ ………………………………………. are groups of organs that work together and
perform a specific task, such as helping the body communicate or defend itself.