Cells are the smallest unit of life and all living things are composed of one or more cells. The three main components that make up cells are macromolecules, water, and nucleic acids. Macromolecules include proteins, lipids, and carbohydrates which provide structure, store energy, carry out functions, and act as protective barriers. Water makes up 70% of a cell's volume and is important for dissolving substances and insulation. Nucleic acids like DNA and RNA carry hereditary information and help regulate cell processes.

1. Cells
Ch. 2.1
http://koning.ecsu.ctstateu.edu/cell/cell.html

2. Focus Questions
1. What is cell theory?
2. What basic substances make up cells?
3. Why are macromolecules important to a
cell?

3. 1. What is cell theory?
Cell theory
All living things
have cells
Cells are the
smallest unit of
life
All cells come
from preexisting
cells

5. Definition of Cell
A cell is the smallest unit that is
capable of performing life
functions.

6. Which is NOT part of the cell
theory?
0% 0% 0% 0%
A. B. C. D.
A. All cells come from
preexisting cells
B. All cells contain a
nucleus
C. All living things
have cells
D. Cells are the
smallest unit of life
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7. Examples of Cells
Amoeba Proteus
Plant Stem
Red Blood Cell
Nerve Cell
Bacteria

8. Which is NOT a macromolecule?
0% 0% 0% 0% 0%
A. B. C. D. E.
A. Carbohydrates
B. Lipids
C. Nucleic Acids
D. Proteins
E. Water
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9. 2. What basic substances make up cells?
Macromolecules
Water Nucleic
Acids
Proteins Lipids Carbohydrates
Definition Water
makes up
___% of a
cell’s
volume
Long
chains of
nucleotides
Long chains
of Amino
acids
Large
macromolecule
that does not
dissolve in
water
Sugar molecules (1, 2,
or long chain)
Examples DNA
RNA
enzymes
hair (horns,
feathers)
fats
oils
sugars
starch
cellulose
Importanc
e to the
cell
• dissolves
substances
• insulates
• carry
hereditary
Information
• used to
make
proteins
• regulate
cell
Processes
• provide
structural
support
• store large
amounts of
Energy
• form
Protective
barrier
around
Cells & cell
parts
• supply energy
for cell
processes
• provide
structural
support

10. Which substance contains
amino acid?
0% 0% 0% 0% 0%
A. B. C. D. E.
A. Carbohydrates
B. Lipids
C. Nucleic Acids
D. Proteins
E. Water
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11. Which 2 macromolecules store
energy?
A. Carbohydrates & Proteins
B. Lipids & Proteins
C. Nucleic Acids & Lipids
D. Lipids & Carbohydrates
0% 0% 0% 0%
A. B. C. D.
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12. Which substance acts as a
protective barrier?
0% 0% 0% 0% 0%
A. B. C. D. E.
A. Carbohydrates
B. Lipids
C. Nucleic Acids
D. Proteins
E. Water
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13. Which substance is made up of
sugars?
0% 0% 0% 0% 0%
A. B. C. D. E.
A. Carbohydrates
B. Lipids
C. Nucleic Acids
D. Proteins
E. Water
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14. Which substance makes up
70% of the cells volume?
0% 0% 0% 0% 0%
A. B. C. D. E.
A. Carbohydrates
B. Lipids
C. Nucleic Acids
D. Proteins
E. Water
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