Life's Chemical Basis- Unit 1 Flashcards
Life's Chemical Basis
Where is methylmercury found
Fish, shellfish and humans
why is methylmercury dangerous
it easily crosses skin and mucous membranes and will damage nervous system, brain, kidneys, and organs and cause Prions disease
Where does methylmercury come from?
Human activities that release mercury atoms (coal burning)
How is Methylmercury absorbed?
Eating, going into eyes, and through skin
Atoms
Fundamental building block of matter
Element
Substance that consists only of atoms with the same number of protons
Nucleus
Core of atom- contains protons and neutrons
Protons
Positively charged subatomic particle that occurs in all atomic nuclei
Neutron
Uncharged particle that occurs in all atomic nuclei
Electron
negatively charged subatomic particle that occupies orbitals around an atomic nuclei
charge
Electrical property, opposites attract, identical repel
Molecules
Atoms interacting with other atoms, its behavior depends on structure of atoms
How are elements defined
By the number of protons in the nucleus
How are periodic tables organized
By atomic number
What groups in the periodic tables act the similar
Elements in columns
Atomic number
Quantity of protons in atomic nucleus
Isotopes
Atoms of elements that differ in mass number
Mass number
Total number of protons and neutrons in a nucleus of an atom
Radioisotopes
Isotope with too many protons or neutrons that are radioactive
How do radioisotopes attempt to stabilize themselves
shed subatomic particles in process of radioactive decay
What can the shedding of subatomic particles in radioisotopes sometimes achieve
It can transform elements
What radioactive isotope is used in a PET scan
MAO-B
What is radioactive decay used for
As a tracer that tracks biological processes inside organisms
How do electrons coexist among atoms
Atoms acquire share and donate electrons
What determines how an atom will interact with others
It’s number of electrons and the arrangement of those electrons
What does the typical atom have of protons and neutrons
Equal amounts
Ionic bond
Strong association between oppositely charged ions resulting in mutual attractions of opposite charges
Example of ionic bonds
Table salt, Sodium and Chloride
Covalent
Atoms share pair of electrons in covalent bond which is nonpolar if sharing is equal and polar if not
Polarity
Separation of molecular charges into positive and negative regions
Hydrogen Bond
Attraction between a covalently bonded hydrogen atom and another atom taking part in a separate covalent bond. Attraction between two due to opposite charges
What is the typical hydrogen bond
Oppositely charged H20 molecules and a bond of different atoms that have different electronegativities
What makes hydrogen bonds strong
When a lot of them are all squished together
What are DNA atoms strong enough to hold
DNA
What happens if radioactive materials hit hydrogen bond
It will break them and cause abnormal arrangements. If hits DNA this will create cancer
3 water properties
Solvent for polar solutes, resistant to temperature changes, and cohesion
How do all the water properties occur
Due to hydrogen bonding
Solvent
liquid that can dissolve salt, sugar and other polar substances
Solute
Dissolved substance
How does water dissolve salt
Water surrounds NaCl and pulls it apart slowly releases ions
Hydrophilic
Substance that dissolves in water easily (salt)
Hydrophobic
Substance that resists dissolving in water (oil)
Why are the 3 water properties important
They are essential for life
Cohesion
Tendency of molecules to stick together
What creates surface tension
cohesion causes molecules to contract to take up a small surface area
What else does cohesion allow for
water to go up plants, resist evaporation, and be sticky
How does water resist evaporation
A lot of heat is needed to break up the hydrogen bonds
Evaporation
Transition of liquid to a gas which requires energy and removes heat from liquid
Why is stabilizing temperature important
Most molecules of life function within a certain range, and it allows for homeostatis
Why is water good for stabilization
Hydrogen bonding needs more heat to raise temperature of water than other liquids
What does ice do to the molecular structure of water
It locks the bonds in a 3-D lattice
Why does ice float
Molecules will pack less densely in ice so they are less dense and lighter than water
What would happen if ice didn’t float
All fish would die
At what PH level does all biological processes occur around
7
What is a PH level
measure of concentration of hydrogen ions (H+)in a fluid
Concentration
Number of molecules of solute per unit of volume of a solution
What do acids do with hydrogen ions
Release them into water
What do bases do with hydrogen ions
Accept hydrogen ionsin water
What does water split into
Hydrogen (H+) and hydroxide (OH-)
What are the amounts of H+ and OH- when Ph is neutral
They are equal
What do strong acids do differently than Weak acids
They release more H+ ions into the water
Example of strong acid
Hydrochloric acid
0=? 14=?
Bigger is base, lower is acid
Acid and base molecules
Acids have a lot of H+
Bases have a lot of OH-
Buffer
Chemicals that stabilize solutions PH by donating and accepting ions that help PH range
Examples of things that are buffered
Cell body and organismal fluids
Acid Rain
Burning fossil fuels releases acid sulfur and nitrogen compounds carried with wind. When mixed with water and oxygen it turns into acidic rain
Air pollution
All ecosystems show detectable effects of air pollution, and mercury levels are still rising
