Biological Concept Introduction & Cells Flashcards
Chapter 1
Biology is the study of what?
Living Things
What is an atom?
The smallest unit of an element that retains all the properties of the element.
What is a molecule?
2 or more atoms linked together
What is the term for anything the occupies space and mass?
Matter
A positive ion is called a ?
Cation
A negative ion is called a ?
Anion
An isotope has the same atomic # but different what 2 things
Different masses and number of neutrons
H2O is the universal solvent meaning it can ..
-H bond with itself
-has high boiling point
-has high melting point
What is the structure of H2O
A bent molecule at 105 degrees, polar molecule can form 4 Hydrogen bonds
If a molecule shares electrons equally its called a
nonpolar covalent bond
If electrons are shared unequally its called a
polar bond
How do enzymes increase the rate of a biological reaction?
By lowering the energy of activation for forward and reverse reactions
Delta G: Free Energy represents
the energy available to do work
+Delta G is
non-spontaneous
-Delta G is
spontaneous
What does a spontaneous reaction mean?
The reaction goes to completion (to the right) by over 50%
Delta G =0 at equilibrium
Delta H: Enthalpy
Heat
*almost all exothermic (heat-releasing) processes are spontaneous
Delta S: Entropy
the amount of randomness or disorder in a system
pH=
-log[H30+]
pOH=
-log[OH-]
Acids will donate what?
H+ ions
Bases will accept what?
H+ ions
A large Ka =
a small pKa, means its a strong acid
pKa=
-logKa
What is a buffer?
a compound that resists pH change
*a weak acid or base and its salt
To solve buffer questions use the Henderson-Hasselbach Equation
pH=pKa+ log [base]/[acid]
Energy can be put into 2 categories
1.) Kinetic: energy of motion (blood flow)
2.) Potential: energy that is stored (glycogen)
Temperature is a measure of what?
Average kinetic energy
1st Law of Thermodynamics:
energy can neither be created nor destroyed but only transferred or changed from one form to another
2nd Law of Thermodynamics:
The entropy (disorder) of the universe is increasing over time
-all processes involve heat loss, with no process being 100% efficient
3rd Law of Thermodynamics
As the temperature approaches absolute zero (-273C or 0K), the entropy of a system is minimum
What is heat?
The transfer of thermal energy between 2 bodies
What is the direction heat travels?
From hot object to cold object
What is an open system?
Mass and energy can exchange
ex: H2O in an open container
What is a closed system?
Allows energy to transfer, but not mass
ex: H2O in a closed flask
What is an isolated system?
Neither energy nor mass can transfer
ex: H2O in a flask is closed and placed in a vacuum jacket
What is an exothermic reaction?
It gives off heat so the surroundings get hot
What is an endothermic reaction?
It absorbs heat so the surroundings get cold
Solid to Liquid
Melting delta H is +
Liquid to Solid
Freezing delta H is -
Liquid to Gas
Vaporization (boiling) delta H is +
Gas to Liquid
Condensing delta H is -
Solid to Gas
Sublimation delta H is +
Gas to Solid
Deposition delta H is -
What does ATP drive?
Endergonic reactions to become exergonic