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Ch. 2 Cell Processes and Energy (Sect.1 & 2)
Name_______________
Period______________
Date_______________
1. A(n) element is any substance that cannot be broken down into simpler
substances. Its smallest unit is the atom
2. When two or more elements combine chemically, they form
a(n) compound. Its smallest unit is called a(n) molecule.
3. A water molecule has two hydrogen atoms and one oxygen
atom. We can write it as H2O.
4. Complete the concept map on organic compounds. Use p.53 in text.
Organic compounds
Contain
carbon
Include
Nucleic acids
carbohydrates
lipids
proteins
5. Compounds that do not contain carbon are called inorganic compounds.
6. Name some foods that are high in protein. Meat, eggs, fish, nuts, and beans
7. How do cells use proteins? They form parts of the cell membrane and make up
organelles. They build body structures like muscle.
8. A(n) enzyme is a type of protein that speeds up a chemical reaction
in a living thing.
9. An energy-rich organic compound is a(n) carbohydrate; sugars
and starches are examples.
**** Proteins are made up of amino acids.
10. Fats, oils, and waxes are lipids. They are organic compounds that
are stored for long term energy.
11. Nucleic acids are large organic molecules that contain the
instructions that the cells need to carry out all the functions of life. There are two
types: Deoxyribonucleic acid which is abbreviated DNA and ribonucleic acid
which is abbreviated RNA.
12. List three ways that cells use water.
a. Chemical reactions need water to dissolve substances and may be part of
reactions
b Water helps keep the cell’s size and shape
c. Water helps keep the temperature of the cell from changing rapidly.
Ch. 2 Cell Processes and Energy (Sect. 1 &2)
p.2
13. The cell membrane is selectively permeable, which means that
some substances can pass through it while others cannot.
14. Name the three ways that substances can move into and out of a cell.
a. diffusion
b. osmosis
c. active transport
15. Diffusion is the process by which molecules tend to move from
a higher concentration to a lower concentration. (Ex: spraying an air freshener or
dropping ink into a glass of water.)
16. What causes diffusion? Molecules are constantly moving and bumping into each
other. This causes the molecules to push farther away from each other and spread
out.
17. Draw molecules on Part B of the diagram below to show how the molecules will
move during diffusion.
H
O
L
Reach equilibrium.
18. The molecules will continue to diffuse until they reach an equal
concentration.
19. In osmosis, water molecules diffuse through a selectively permeable
membrane.
20. Passive transport like osmosis and diffusion requires no
energy. Active transport like engulfing requires energy from the
cell because they are now moving the molecules in the opposite direction from low
concentration to high concentration.