Biol PP 1

what is the universe made of?

energy and matter

Define Diffusion

consequence of the expanding Universe

the net movement from a volume of greater concentration to a volume of lesser concentration

what is matter?

anything that takes up space and can be weighed

what holds matter together?

the 4 fundamental interactions of the Universe:

strong nuclear interaction

electromagnetic interaction

weak nuclear interaction

gravity

which interaction is intrinsic to living systems?

electromagnetic interactions

IF fundamental interactions are ≥ energy

THEN objects are bound together larger structure is stable

IF energy > fundamental interactions

THEN objects separate larger structure dissolves

what are the levels of organization of matter on Non-living matter?

elementary particles

subatomic particles

atoms

molecules

small biological molecules

biological macromolecules

what are the levels of organization of matter on living systems?

cells

tissues

organs

organ systems

organisms

populations

communities

ecosystems

biones

biosphere

what are the 3 subatomic particles?

protons, neutrons, electrons

what part of an atom is important in biological systems?

electrons carry energy that can be used by living systems

what is the structure of an atomic nucleus?

protons and neutrons are held together by the strong nuclear information

nucleus of a carbon atom: 6 protons, 6 neutrons (most common isotope)

what is the structure of an atom?

the quantum-mechanical model is the current best physical explanation of the structure of atoms

what is an orbital

volume of space around a nucleus in which electrons are most likely to be found ( an orbital can hold 0, 1, or 2 electrons )

Do all orbitals have the same geometries?

orbitals have different:

shapes

spatial orientations

this will limit the spatial orientations of covalent bonds

do electrons in different orbitals hold the same amount of energy?

in order for an electron to be in an orbital, the electron must carry a specific amount of energy. Normally, lowest-energy orbitals are filled first.

what is the function of an atom?

the smallest unit of an element

what is an element?

a substance that cannot be converted to simpler substances by ordinary chemical means

which elements will we discuss most often when describing living systems?

Sulfur

phosphorus

oxygen

nitrogen

carbon

hydrogen

what is a covalent bond?

the sharing of a pair of electrons between 2 atoms

what happens to the energy that electrons carry when they enter into a covalent bond?

when covalent bonds are formed, energy is released

what is a molecule?

a stable and predictable covalent association between at least 2 atoms

what is a compound?

a molecule that is made of more than one kind of atom

what is an “organic compound'“?

any molecule that has at least one C-C or C-H bond

what is an ion?

an atom that has gained or lost at least one electron

are covalent bonds made in any direction?

covalent bonds of molecules are formed within the same volumes that atomic orbitals occupy

how might electrical charge be unequally distributed across an atom?

lone pairs ar volumes of strong negative charge

what is electronegativity?

a measurement of the strength with which a nucleus attracts electrons

what is polarity?

is a covalent bond, a condition that is the result of an unequal sharing of electrons

this results in an unequal distribution of charge between the atoms

define hydrophilic molecule

a molecule that can be dissolve in water because it has charged atoms and/or polar bonds

define hydrophobic molecules

a molecule that cannot dissolve in water because it lacks charged atoms and/or polar bonds

why care about how molecules interact with water?

biochemical reactions take place in water

if there is not enough water, then biochemical reactions will not occur

if sometimes is not dissolved in water, then it cannot enter into any biochemical reactions

what is an ionic bond?

an electrical attraction between ions of opposite charge

what is a hydrogen bond?

a hydrogen atom that has a partial positive charge AND another atom that has a partial negative charge

what is the hydrophobic effect?

energetically favorable association of non polar surfaces in an aqueous solutions

are all kinds of bond of equal strength?

the geometries and natures of nuclei and electrons are the basis for chemical bonds and interactions

what is an acid?

molecule that donates protons

what is a base?

molecule that accepts protons

what is pH?

negative logarithm of the concentration of H+ ions

7 under is acidic

7 over is basic

what happens during chemical reactions?

old covalent bonds are broken (energy is absorbed)

new covalent bonds are made (energy is released)

define hydrolisis

A chemical reaction in which water is used to break down a compound

what is energy?

the ability to do work

what is work?

force applied over a distance

what is heat?

the transfer of internal energy

do all the electrons in an atom carry the same amount of energy?

an electron that absorbs additional energy can move to a higher energy level in the atom

an electron that moved to a lower energy level in the atom must release energy

what part of an atom is important in biological systems?

The processes of respiration (aerobic or anaerobic)

and/or fermentation are used to transfer energy from high-energy electrons to electrons of molecules in the cell.

molecules I the cell use energy from electrons to perform work on other molecules. These biochemical reactions are life.

where can diffusion only be found?

Diffusion can only be found where there is an unequal distribution of matter and energy.

where can life be found?

Life can be found where there is a net flow of energy and matter:i.e. where there is an unequal distribution of matter/energy