Ch. 02 - Chemistry Flashcards
Chemistry is the study of what?
the composition of matter
What is matter?
matter is anything that takes up space and has mass
What is mass?
a measure of the amount of matter an object contains
What is weight?
a measure of the pull of gravity on a mass
What are the three states of matter?
Solid, Liquid, and Gas
What’s an element?
a substance that cannot be broken down into other substances by chemical means
How many naturally occurring elements are there?
92
How many of the naturally occurring elements are essential for life?
25
What are the 4 elements that make up 96% of living matter?
Carbon (C), Oxygen (O), Hydrogen (H), Nitrogen (N)
A chemical reaction in which the amount of energy released is greater than the activation energy needed to start the reaction is called:
Exergonic Reaction
What do enzymes do?
- Act as biological catalysts
- They are proteins
- They accelerate chemical reactions
- ALWAYS LOWER the activation energy required to start a chemical reaction
What is an anion?
An anion is a negatively charged atom or group of atoms
A type of reaction in which simple molecules are bonded together to make a larger, more complicated molecule is called a(n) ______ reaction.
Anabolic (or Synthesis) Reaction
What is the type of chemical reaction that breaks a molecule into smaller fragments by breaking its chemical bonds?
Decomposition (catabolic) Reaction
A pure chemical substance made up of atoms of two or more types of elements in a fixed proportion is called _____.
A Compound
The presence of an appropriate enzyme affects only the ____.
rate of the reaction
The pH of a solution indicates the:
concentration of hydrogen ions it contains
What are the important classes of lipids?
fatty acids, eicosanoids, glycerides, steroids, and phospholipids and glycolipids
triglycerides (neutral fats)
3 fatty acid molecules attached by dehydration synthesis to a molecule of glycerol
diglycerides
2 fatty acids and glycerol
monoglycerides
1 fatty acid + glycerol
Steriods
(1) components of plasma membranes
(2) include sex hormones
(3) important in lipid digestion
phospholipids and glycolipids
structural lipids that are components of micelles and plasma membranes
Proteins
- contain carbon, hydrogen, oxygen, and nitrogen
- formed from amino acids
