Chapter 2: The Chemical Basis of Life Flashcards
What are the typically referenced main elements
CHNOPS, carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur
What is matter?
Anything that occupies space and has mass. It makes up living organisms and is made up of elements
What are elements?
Substances that cannot be broken sown to other substances by ordinary means. Each element has a symbol, and there are 92 elements found in nature.
What do 96% of living organisms consist of?
oxygen, carbon, hydrogen, nitrogen
What does the other 4% of living organisms consist of?
Calcium, phosphorus, potassium, sulfurr, sodium, chlorine, and magnesium
What are trace elements?
Elements that are only needed for life in very small quantities but are still necessary
Compound
substance containing 2+ elements in a fixed ratio;
Atoms
the smallest unit of matter that retains the properties of a given element
subatomic particles
smaller than an atom, protons and neutrons found in atom’s nucleus, electrons orbit nucleus in electron cloud since the speed of electrons is nearly the speed of light
electron arrangement
the farther an electron is from the nucleus, the greater its energy. electrons occur in electron shells (1, 2, or more). The innermost shells fill up with only 2 electrons, outermost shells of most main elements of life can hold 8 electrons or 4 pairs
Filling the outermost electron shell
Elements that do not have outer shell filled readily react with other elements to fill those shells. chemical bonds take place when atoms share/donate/receive other electrons, and so stay close together held by attraction
Octet Rule
says that atoms tend to gain, lose, or share their electrons so as to have 8 electrons in outer electron shell
Name parts of an atom and charges
nucleus- protons (+) and neutrons (no charge)
electrons(-) are in the surrounding electron cloud
name 2 key trace elements discussed and their importance
iron is necessary for energy processing and transporting oxygen in blood, need it so you don’t get anemia
iodine is essential ingredient of a hormone produced by thyroid gland
why does bonding take place?
because the goal of each atom is to have a full outer shell, in most cases 8 electrons, otherwise known as octet rule (except for H and He which only need 2)
what’s the difference between polar and non polar bonds?
non polar bonds are shared equally and polar bonds are not
what is the difference between cohesion and adhesion?
cohesion is anything sticking to more of its same kind, adhesion is two different kinds of things sticking to one another
what is the difference between a solvent and a solute?
A solute will always dissolve in the solvent
xylem vs phloem
xylem transfers minerals and waters, and phloem transfers organic materials
what is acid on a pH scale
0 to anything below 7
what is neutral on ph scale
7
what is basic on pH scale
anything above 7 to 14
what does likes dissolve likes mean
polar molecules will dissolve polar molecules, non-polar dissolves non-polar, non-polar and polar do not dissolve
In terms of the donation or the acceptance of protons, please compare and contrast acids and bases.
Acids donate Hydrogen ions (protons) to a solution whereas bases are proton acceptors
