Download Chapter 1, Section 3 Notes

Chapter 1, Section 3 Notes
I.
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III.
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VI.
Elements and Compounds
a. Element: substance that cannot be broken down
i. Smallest unit of element = atom
ii. Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur found in
living things
b. compound: two or more elements chemically combine
i. smallest unit of compound = molecule
ii. example: water (2 hydrogen atoms & 1 oxygen atom)
c. organic: compounds that contain carbon
i. four types of organic compounds in living things
d. inorganic: does not contain carbon
Carbohydrates
a. Contain the elements hydrogen, oxygen, and carbon
b. Sugars combine to form starches (store excess energy)
i. Found in foods that come from plants
Lipids
a. Includes fats, oils, and waxes
b. Contain more energy than carbohydrates (cells store energy in lipids)
c. Make-up cell membranes
Proteins
a. Made of smaller molecules called amino acids
i. Amino acids (only 20) can be rearranged to create thousands of different
proteins
b. create most structures in a cell
c. produce enzymes = speed up chemical reactions
Nucleic Acids
a. Contain instructions for carrying out life functions
b. Two types of nucleic acids:
i. DNA – carries information and is passed from parent to offspring
ii. RNA – found in cytoplasm and has a role in creating proteins
Water and Living Things
a. Four important roles for water
i. Chemical reactions involve water
ii. Helps cells keep their size and shape
iii. Helps keep temperature of cells from changing too rapidly
iv. Chemical reactions use substances that are dissolved in water