Basic Biochem Flashcards
Proton (+)
define the atomic number and element
Electron (-)
interact in bonds. occupy space >100,000 times the width of atomic nucleus
Neutron (no charge)
help form nucleus, contribute to atomic mass and isotopes
Atom
the basic unit of matter
Atoms come in what?
elements, each element is defined by the number of protons in the nucleus (atomic number)
Electrons occupy?
orbitals: 3D spaces around the nucleus where they can interact with neighboring atoms
Electrons define
a fixed number of electrons can fit in a given energy level around the nucleus. each energy level is subdivided into orbital clouds of particular shape
Energy levels
- electrons have potential energy related to their position
- electrons farther from the atomic nucleus have more energy
- the chemistry of life capitalizes on this property to capture and use chemical energy
Elements of life
carbon, hydrogen, oxygen, nitrogen, and Potassium
C,H,O,N,P
represent more than 95% of the matter in all life
Carbon
the backbone of of biomolecules
Hydrogen
most abundent in number
Life
based on smaller atoms that are common in the universe, due to the way atoms are naturally made
Isotopes
version of an element where the number of neutrons varies. Isotopes have same chemical behavior but are often rare
ex: hydrogen-1 (protium), hydrogen-2 (deuterium), and hydrogen-3 (tritium),
Mass Spectrometers
special tool that can detect isotopes, separates and measures atoms by mass and quantity
Radioisotopes
emit radiation energy detected by spectroscope
Radioactive Decay
some isotopes decay into daughter elements at fix rates
Isotope fingerprint
stable isotope ratios can vary in samples often by natural region
Covalent bond
sharing of electrons to achieve full valence orbits between bonded atoms
Ionic bond
transfer of electrons
Ions
- charged atoms of molecules
- occurs when an atom or moles gains or loses electrons to gain stability in electron orbitals
- most common among atoms near noble gases
ex: sodium ion (Na+), chloride ion (Cl-), and calcium ion (Ca2+).
Anions
negative ions
Cations
positive ions
Opposite charges
attract to form ionic bonds
Atom bond
a single atom can form multiple covalent bonds
Four Valence Electrons
available to form up to four stable bonds that are equidistant from one another
Polyatomic Ions
some covalently bonded molecules can also become ions to form more stable structures
Polar Covalent Bond
bonding electrons shared unequally between two atoms, partial changes in atoms
Nonpolar Covalent Bond
bonding electrons shared equally between two atoms, no charge on atoms
Cohesion
polar attraction between molecules of the same kind, forms hydrogen bonds
Adhesion
polar attraction between different molecules
Hydrophilic
water loving substance, usually rich in atoms of O or N
Hydrophobic
molecules that do not dissolve in water like oils and waxes
Capillary Action
combines cohesion and adhesion
Properties of water
- Water is both cohesive and adhesive
- Water is a good solvent
- Water organizes nonpolar molecules
- Solid water is less dense than liquid water
- Water has a high specific heat
- Water has high heat of evaporation
Three states of water
vapor, liquid, ice
Exergonic Reaction
release energy by breaking high energy bonds to form lower energy bonds
Endergonic
absorb energy, require energy to occur usually produces more complex molecules from simpler units
Oxidation
Endergonic Reaction
Low energy bonds are broken are broken to form high energy bonds
Oxidation- Reduction (redox)
reactions involve electron transfer b/w reactants:
– Oxidation- Loss of electrons, tend gain O but lose energy.
– Reduction- Gain of electrons, tend to gain H and energy.
Acids
compounds that release H+, pH less than 7
Bases
compounds that accept H+ pH greater than 7
pH
a measure of how acidic/basic water is.
amphipathic molecule
chemical compounds that have both polar and nonpolar parts.
