Exam # 1 - Lecture Notes 1-6 Flashcards
What are the eight characteristics of life?
1) Regulated
2) Responsive
3) Reproduces
4) Uses energy
5) Grows
6) Carries instructions
7) Complex/ordered
8) Well-adapted
Does a bacteria cell qualify as life?
Yes, absolutely
Is a virus alive?
No. The virus is not alive because it depends so fundamentally on the cell in order to accomplish the qualities of life
Nothing less than a ____ is alive.
cell
What did Stanley Miller get when he did his experiment?
Amino acids
How many elements occur naturally?
92
How many elements are essential to life?
25
Which four elements make up 96% of living matter?
CHON
Which elements make up the remaining 4%?
Na, P, S, Ca, K, Mg, Cl
The remaining fourteen elements are each present less than ___%. These elements are called _____ elements.
.01%. Trace
If the human body lacks iodine you get ______.
goiter
Atoms combine into ________.
molecules
______ are used for individual atoms and molecules…really tiny matter that you can’t even see.
Dalton’s
The electron is important for two reasons, what are those two reasons?
1) Chemical bonding
2) Storing energy - POTENTIAL ENERGY
______ are atoms that vary in their number of neutrons.
Isotopes
If you are studying the chemistry of the cell, this is referred to as…
metabolism
In biology, it’s not electrons flowing through a copper wire…it’s electrons in…
biological molecules
Why are different elements required for life? Does it matter where an element is on the periodic table? Does it tell us anything about its properties?
Yeah, HOW IT REACTS
The various atoms want to fill…
their outer shells
Behavior depends on the ______ electrons.
valence
What are electrons called in the outer shell?
Valence electrons
Which theory more accurately describes an electrons position in space?
Orbital theory
How many orbitals are contained in the first shell?
One orbital
What’s the orbital called in the first shell and what’s its shape?
s orbital, spherical
How many orbitals are found in the second shell?
FOUR orbitals
How many electrons does one orbital hold?
TWO electrons
The first shell can hold a maximum of ___ electrons. The second shell can hold ____ orbitals, and each one can hold a maximum of _____ electrons.
two, four, two
The _____ rule means you want to have _____ electrons.
octet rule, eight electrons
If you’re hydrogen, you want to have ____ electrons to complete your shell, since only one electron fills its first shell.
two
When a hydrogen bonds with another hydrogen, it forms a covalent bond. H-H. That new hydrogen is no longer an atom, but a ________.
molecule.
How many covalent bonds will oxygen form?
TWO COVALENT BONDS because it already has six electrons in its second shell.
Define a molecule…
Atoms held together by covalent bonds.
How many covalent bonds does phosphorus form?
FIVE covalent bonds. Three single covalent and two double covalent
Phosphorus in biology is typically bonded to _______.
oxygen
Is water charged?
NO, WATER IS NOT CHARGED
There are _____ charges within water due to unequal sharing of electrons.
partial
Is having partial charges within a molecule the same thing as being charged?
No.
Where do you expect partial charges to be in the biological molecule?
CHON
In CHON, which are more electronegative and which are less electronegative?
More electronegative = O and N
Less electronegative = C and H
What happens when you get either O and N with either C or H?
You get partial charge
We are ______ based.
carbon
If your biological molecule has either _____ or _____ in it…you’ll have partial charge.
Oxygen or nitrogen
What is a polar covalent bond?
A bond where the sharing of electrons are unequal
Oxygen contains two polar/non-polar covalent bonds?
two non-polar covalent bonds because they have equal electronegativity, and also because their electrons share equally
What is a non-polar covalent bond?
A bond where the electrons equally share
Hydrogen contains a polar/non-polar covalent bond?
non-polar covalent bond
Is methane polar or non-polar?
non-polar because no partial charge and the electrons share equally
Name the four weak interactions
ionic bonds, hydrogen bonds, van der Waals interactions and hydrophobic interactions
Ionic bond, weak or strong in biology?
WEAK
Compounds held together ionically are called _____.
salts
Can a molecule be an ion?
Yes
Ammonium chloride…what is that?
The chloride is an anion and the ammonium is actually the cation…it has a positive charge…so they stick together…salt
Inorganic phosphate….molecule?
Yes, it’s a molecule…BUT IT’S ALSO AN ION BECAUSE WE GAINED AN ELECTRON!
Bio molecules usually bear partial and full charges which dictates their _______ and _______.
structures and functions
What’s the charge of DNA?
Negative charge because of the ACID
The strength of an ionic bond depends on the _______.
environment
In water, ionic bonds have _/__ the strength of covalent bonds.
1/10th
The cell itself is __% water.
70%
What is required in a hydrogen bond?
1) hydrogen - must have a partial charge
2) the hydrogen needs to be bonded to oxygen or nitrogen
Are hydrogens in water suited for hydrogen bonding?
Absolutely
Van der Waals interactions can occur between…
two non-polar chemical groups
Van der Waals interactions can occur between two non-polar chemical groups which means…
no partial charge
What are transient partial charges?
Temporary, brief, not permanent
Hydrophobic interactions can also occur between…
two non-polar chemical groups
What chemical groups don’t like water?
non-polar chemical groups don’t like water
Why don’t non-polar chemical groups like water?
They’re not charged…they don’t have partial charge.
What are the two ways in which weak interactions are important?
Weak interactions work both intermolecularly and intramolecularly…
They work intErmolecularly to hold two molecules togEther.
They work intrAmolecularly to establish the molecule’s 3D shApe.
What four reasons determine shape?
1) which atoms are bonded to each other
2) the orbitals
3) Intramolecular weak interactions
4) Environmental conditions - oil sticks together in water
When covalent bonds form, valance shell orbitals _______ and _______.
combine and rearrange
Which atoms among CHON does this type of hybridization pertain to?
Carbon, Oxygen and Nitrogen
Sp3 hybridizations happens when these three atoms form…
SINGLE COVALENT BONDS
When a carbon forms with hydrogen to form methane, you get…
SP3 HYBRIDIZATION. SINGLE COVALENT BONDS.
What is it that makes the chain fold?
Weak interactions
__________ weak interactions help determine shape.
intramolecular
At chemical equilibrium, what is equal?
The rates forwards and the rates backwards
Does equilibrium happen in the cells?
NO. Equilibrium is a principle that is applicable to the test tube where we can isolate a reaction.
Reactions in the cell run in metabolic pathways, THERE IS NO EQUILIBRIUM IN THE CELL.
When did the Earth form?
4.54 billion years ago
When did life appear?
3-4 billion years ago