AP BIO 1.1 - 1.3

Why is water polar?

electronegativity of O causing slight negative charge of O and partial positive charge of H

Capillary action

spontaneous upward movement of liquid in a narrow tube or porous material, against gravity, caused by the adhesive forces between the liquid and the material, and cohesive forces within the liquid

What are the properites of water?

Dense solid state, high heat capacity, high heat of vaporization, universal solvent, cohesion+adhesion, surface tension

Surface tension

caused by hydrogen bonding, when molecules on the surface have nothing to pull them from the air above, so they form bonds with their neighboring molecule, causing stronger IMF.

• gets tighter

• more attracted to each other

• stronger cohesion

Solvent

Because of its polarity, the negative ends attaches to solute cation and positive ends attract to solute’s anion.

• it can dissolve anything with charge (polar/ionic)

Ice

the molecules of water gets pushed away from each other in solid state. As a result, the molecules of water are less dense and floats.

High Heat capacity

• high amount of heat needed to raise the amount of heat

• minimizes change in temperature

• because of hydrogen bonds, water requires a large amount of energy to break before the water molecules can move faster and increase in temperature

High heat of vaporization

• the hydrogen are very strong, so to break them requires a lot of energy. When the bonds are broken and H2O turns to it’s gas stage, the kinetic energy is lost, taking away energy, leaving a cooling effect

What is Carbon?

• Key component for macromolecules

• carbon bonds are exceptionally stableCarbon due to carbon's unique ability to form strong, covalent bonds with itself and other elements

• Forms 4 bonds, so it serves as a backbone for macromolecules

Hydrocarbon

• Covalent bonds between atoms in hydrocarbons store energy, making it a good fuel when burned

• Can form 5 and 6 membered rings

• Single or double bonds may connect the carbons in the ring

  Nitrogen may be substituted for carbon

Benzene

An important hydrocarbon rings, used in some amino acids, cholesterol, and its derivatives

Isomers

molecules that have the same chemical formula but differ in placement/arrangement of atoms or types of bonds between atoms

What are the 3 types of isomers?

1. Structural isomers - have a different covalent arrangement of atoms.

2. Geometric isomers -  have a different arrangement of atoms around a double bond

3. Enantiomers  - molecules that share chemical formula and bonds but differ in 3D placement of atoms; mirror images

Hydroxyl group

• polar

• alcohols

• increases the solubility and boiling points of molecules it's attached to due to H-Bonds

Aldehyde

• c=o is very reactive

• important in building molecules + energy-releasing reactions

Keto

• important in carbohydrates and in energy reactions

Carboxyl

• acidic

• carboxylic acids

• Ionizes in living tissues to form COO⁻ and H⁺

• Enters into condensation reactions by giving up its —OH group.

• Some important in energy-releasing reactions.

Amino

• Basic

• Accepts H⁺ in living tissues to form —NH₃⁺

• Enters into condensation reactions by giving up H⁺.

Phosphate

• Negatively charged

• Enters into condensation reactions by giving up —OH

• When bonded to another phosphate, hydrolysis releases much energy

Sulfhydryl

• By giving up H, two —SH groups can react to form a disulfide bridge (S—S), stabilizing protein structure

What are the 4 types of macromolecules?

carbohydrates, lipids, proteins, nucleic acid

monomers and polymers

• Macromolecules consist of individual subunits called monomers

• Monomers are linked together via covalent bonds into polymers

Dehydration synthesis

• joins monomors together

• forms a covalent bond

• releases H2O

• releases energy

Hydrolysis

• breaks polymers

• 1 monomer gain OH, 1 gains H

• requires energy

Enzymes

• speed u reaction for hydrolysis and dehydration synthesis

• enzymes that helps with hydrolysis ends with -ase

Anabolism

link simpler molecules to form more complex ones, requires energy that are captured in chemical bonds that form

Catabolism

break down molecules, releasing energy

metabolism

• chemical reactions in a living organism that sustain life, transforming food into energy, providing building blocks for cells and tissues, and eliminating waste products

• anabolism + metabolism

• creates more disorder

Entropy

• If there are fewer products than reactants, the disorder is reduced; this requires energy to achieve

• If a chemical reaction increases entropy, its products are more disordered or random than its reactants.

• +G(energy to do work) → -S (entropy)

Laws of thermodynamics

1. Energy is neither created nor destroyed

2. Second law: Disorder (entropy) tends to increase. 

   When energy is converted from one form to another, some of that energy becomes unavailable for doing work (is lost from the system often as heat energy).

3. In a closed system with repeated transformation, free energy decreases and unusable energy increases