Chapter 2/Chemical Composition of the Body Flashcards
Everything that takes up space and has mass
Matter
Smallest unit of matter
-protons
-neutrons
-electrons
atoms
In the atomic nucleus
Protons and neutrons
orbits the nucleus at various distance
electrons
Chemical element has a specific # of protons
atomic number
of protons equal
of electrons
Atomic mass
protons + neutrons
Elements can exist as isotopes
Differ in the # of neutrons
unstable isotope, emits energy
radioisotopes
The amount (grams) equal to the numerical value of the atomic weight
Gram atomic mass
Atoms that gain or lose electrons, acquire a net electrical charge
ion
Net positive charge
cation
net negative charge
anions
-Two or more atoms bonded together
-Represented by their component atoms
C6h12O6(glucose)
molecules
One or more electrons in the outer orbital are shared between atoms
Covalent bonds
-Electrons are not shared equally between atoms
-One acquires slight negative charge, the other becomes slightly positive
Polar covalents bond
Electrons are shared equally
Non-polar covalent bond
the attraction between two oppositely charged ions
-dissolve easily in water
ionic bond
electrical attraction between slightly positive hydrogen and slightly negative atoms ( oxygen, nitrogen)
-very weak individually
-But in large numbers can play an important role
hydrogen role
-Molecules are three-dimensional
- Rotation around chemical bonds allows different molecules shapes
Molecular Shape
Ionization can occur in atoms covalently linked in molecules
Ionic molecules
-Atoms with unpaired electrons in an outermost shell
-Unstable and highly reactive, pull electrons from another atoms to fill their shell
Free Radicals
Substances dissolved in a liquid
solutes
The liquid in which solutes are dissolved is the
solvent
Solute + Solvent
Solution
-Polar molecules
-Liquid over broad range ( 0-100)
-High heat capacity
Water
-Hydrolysis
-Dehydration synthesis
Water reactions
Molecules that easily dissolve in water
- Contain polar covalent bonds or ionized groups
– Electrical attraction to water.
Hydrophilic
molecules that do not dissolve
in water. (Oil in water)
– Contain non-polar covalent bonds.
– Separate into two phases
Hydrophobic
- Molecules that have a
the polar region at one end
and a nonpolar region
at the opposite end. - Form cluster in water
- Important function in
plasma membrane
structure
Amphipathic Molecules
The amount of solute dissolved per liter of
solution
Concentration
increase H+ concentration (release H+)
acids
decrease H+ concentration (release OH-)
bases
Amount of H+ in a solution is expressed
pH
Carbohydrates composed of
C,H, O
Provide cells with energy
Monosaccharide
glycogen-an energy reservoir
hydrolysis of glycogen release glucose into the blood
Polysaccharides
