Biochemistry Flashcards
Chemical Energy
- main type of energy
Stored in bonds of chemical substances.
Radioisotopes
Are isotopes that decompose to more stable forms.
Radioisotopes
-Atom loses various subatomic particles
Sometimes loss results in an isotope becoming a different element.
Radioisotopes
-As isotopes decay, subatomic particles that are being given off release some energy…
This is called radioactivity
- can be detected and measured with a scanner.
Three basic types of mixtures…
Solution
Colloid
Suspension
Solutions
Solute partials are very tiny, do not settle out or scatter light
Example: mineral water, sugar water
This a homogeneous mixture
*compounds don’t separate (layers) over time when left standing
Colloid (mixture)
Solute partials are larger than in a solution and scatter light; do not settle out.
Example: jell-o, whole milk and shampoo
Considered heterogenous mixture
*compounds don’t separate (layers) over time
Suspension (mixture)
Solute particles are very large, settle out, and may scatter light.
Examples: oil shaken in water, muddy water, and blood
Considered a heterogeneous mixture
*compounds separate (layers) when left standing over time.
What kind of bonds form between water molecules?
Hydrogen bonds
**But each molecule itself has a covalent bond
Oxygen and Argon are both gasses. Oxygen combines readily with other elements, but Argon does not. Why?
Argon’s valence shell is full. So non-reactive
Assume imaginary compound XY has a polar covalent bond. How does it’s charge distribution differ from that of XX molecules?
Electrons would spend more time in the vicinity of the more electronegative atom in XY , whereas electrons in XX would orbit both X atoms to an equal extent.
Covalent bond
Electron sharing that produces a molecule in which shares electrons occupy a single orbital common to both atoms.
Chemical bonds
Energy relationships between electrons of exacting atoms.
* not actual physical structures
Octet Rule
Atoms want 8 electrons in their valence shell.
(Exception of small atoms like H and He they only want 2)
Wanting 8 electrons is the driving force of chemical reactions
(Noble gases have full octets and are less reactive)
Ionic Bonds
Involve transfer of valence shell electrons from one atom to another, resulting in ions
Anion
Negative charged
- ion that’s gains one or more electrons.
Cation
Positive charge
*ion that lost one or more electrons.
Polar Covalent Bonds
Unequal sharing of electrons between 2 atoms, results in electrically polar molecules.
*Atoms have different electron- attracting abilities.
Synthesis reaction
Building
Small particles (monomers) are bonded to form a larger, more complex molecules (polymers).
Example: amino acids join together to form a protein molecule
Decomposition Reactions
Breaking Down
Bonds are broken in larger molecules, resulting in smaller, less complex molecules.
Example: glycogen is broken down to release glucose molecules.
Salts are electrolytes. What does that mean?
Electrolytes are substances that will conduct an electrical current in aqueous solution.
Which ion is responsible for increasing acidity?
H+
Which ion is responsible for increasing basicity?
OH-
To minimize the sharp pH shift that occurs when a strong acid is added to a solution, is it better to add a weak base or a strong base, why?
A weak base to act as a buffer to the strong acid.
