the chemical context of life Flashcards
What is the fundamental idea that living organisms and the world they live in are subject to?
The basic laws of physics and chemistry.
What makes biology a multidisciplinary science?
It draws on insights from other sciences.
How can life be organized structurally?
It can be organized into a hierarchy of structural levels.
What are emergent properties in the context of biology?
Additional properties that appear at each successive structural level.
Define matter.
Matter is anything that takes up space and has mass.
What is an element?
A substance that cannot be broken down into other substances by chemical reactions.
How many naturally occurring elements are there?
92 naturally occurring elements.
What is a compound?
A substance consisting of two or more elements in a fixed ratio.
Provide an example of a compound.
Table salt (sodium chloride or NaCl) with equal numbers of chlorine and sodium atoms.
How many chemical elements are essential to life?
About 25 of the 92 natural elements are essential for life.
What is an atom?
The smallest unit of matter that retains the properties of an element.
What are the three main subatomic particles in an atom?
Protons, neutrons, and electrons.
What is an atomic number?
The number of protons in an atom’s nucleus.
What is the mass number of an atom?
The sum of protons and neutrons in the nucleus.
What are isotopes?
Atoms of the same element with different numbers of neutrons.
