Ap Bio Unit 1

The Chemistry of Life

Covalent Bond

The sharing of a pair of valence electrons by 2 atoms

Polar Bond

The covalent bond between atoms that don’t share electrons equally

Nonpolar Bond

When electrons are shared equally

Ionic Bond

When 2 ions bond (1 giver/1taker). Cations bond with anions (+/-)

Hydrogen Bond

The non covalent attraction between a hydrogen atom and an electronegative atom with a partial charge

Van der Waals Interactions

The slight, fleeting attractions between positive and negative charges that enable all atoms and molecules to stick (Gecko)

The strongest bonds

Covalent, polar, non polar, and ionic bonds

Weaker Bond

Hydrogen Bond

Weakest Bond

Van der Waals Interaction

Cohesion

Hydrogen bonding between like molecules

Surface Tension

Measure of how difficult it is to break or stretch the surface of a liquid

Adhesion

The bonding between unlike molecules

Transpiration

This is the movement of H2O up plants

Temperature

The measure of intensity of heat due to average KE of molecules

Capillary Action

The tendency of water to rise in a thin tube, due to cohesion and adhesions

Thermal Energy

The total amount of KE in a system

High Specific Heat

The ability of water to resist changes in temperature

Evaporative Cooling

Molecules with greatest KE leave as a gas

Insulation by Ice

Less dense, floating ice insulates liquid water below

Solution

Liquid, homogeneous mixture of 2+ substances

Solvent

Dissolving agent (liquid)

Solute

Dissolved substance

Water

Versatile Solvent

Hydrophilic

Affinity for water, polar, ions

Hydrophobic

Repel water, non polar

Acid

Increases H+ concentration (HCl) (0-7)

Base

Reduces H+ concentration (NaOH) (7-14)

Carbon

The most important to life because of its versatile bonding behavior. It can form up to 4 single, double, or triple covalent bonds with other atoms and can form rings or chains. The atoms can also be remodeled into a variety of organic compounds

Functional Groups

Chemical groups that affect molecular function by being directly involved in chemical reactions. Helps determine how that molecule will behave chemically; gives it shape

Hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, and methyl

The 7 functional groups

Hydroxyl

Because of oxygen, it adds to polarity

Carboxyl

Found on every amino acid. Acts as an acid

Carbonyl

Tends to be found in sugars. Also adds to polarity

Amino

Acts as a base. Found on every amino acid

Sulfhydryl

will form the covalent cross-links with other cysteines in the tertiary and quaternary protein structures

Phosphate

Considered an energy releasing side group

Methyl

Nonpolar

Monomers

Molecules used as repeatable subunits to build larger molecules

Polymers

Larger molecules that are built from chains of monomers

Dehydration Synthesis

How cells build large molecules from smaller ones. An enzyme removes a hydroxyl group from one molecule and a hydrogen atom from another. A covalent bond forms between the mecums, and water also forms.

Monosaccarides

The monomers of carbohydrates

Glycosidic

The bond of carbohydrates

Amino Acids

The monomers of protein

Peptide

The bond of protein

Nucleotides

The monomers of nucleic acids

Phosphodiester

The bond of nucleic acids

Hydrolysis

How cells split large molecules into smaller ones. An enzyme attaches a hydroxyl group and a hydrogen atom (both from water) at the cleavage site

Carbohydrates

These consist of CHO in a 1:2:1 ratio and can be used for energy structure and for storing/transporting energy quickly

Monosaccharides

These are the monomers of carbohydrates also called simple sugars and are mostly used as an energy source or structure and are very soluble in water. They may be linear or ring form

Disaccharides (Oligosaccharides)

These are made of 2 monosaccharides joined together

Polysaccharides

These are also called complex carbs since they contain many monomers. They can be branched or in straight chains

Lipids

These function as long term energy storage and the structural foundation of cell membranes. They can be fatty, oily, or waxy, are made up of CHO, and are insoluble in water

Fatty Acids

These are simple organic compounds with a carboxyl group joined to the backbone of 4 to 36 carbon atoms

Hydrocarbon tails

These are hydrophobic

Carboxyl Group “Head”

This is hydrophilic

Saturated Fatty Acids

These are single bonds within their hydrogen tails. They are fully saturated with hydrogen atoms and the tails are flexible. They can “stack up” at room temp, forming a soft solid (butter) and most animal fats are made up of them

Unsaturated Fatty Acids

These contain 1 or more double bonds in the carbon chain making the hydrocarbon tails slightly bent. They are less flexible and because they can’t stack together, they will be a liquid at room temperature

Fats

These are lipids with 1,2, or 3 fatty acids bonded to glycerol (alcohol). The fatty acid attaches to a glycerol via the carboxyl group, then losing its hydrophilic properties. Ex: triglycerides and phospholipids

Waxes

Complex molecules with a varied mixture of lipids with long fatty acid tails bonded to one chain alcohols or carbon rings. The molecules of these pack tightly, making them firm and water resistant

Steroids

These are lipids with a rigid backbone of 4 carbon rings and no fatty acid tails. Cholesterol and estrogen are examples of these

Cholesterol

The most common steroid in animal cell membranes

Estrogen and Testosterone

These govern reproduction and reproductive system development

Proteins

All cellular processes involve these. They are the most diverse molecule and are used for motor, defense, storage, regulatory, sensory, transport, enzyme, structural and signaling

Amino Acids

These are the monomer of protein, There are 20 possible, all with an amine group carboxyl group, and variable group. CHON is found in all of these and all of proteins

R Group

This gives amino acids their properties-hydrophobic/philic, acid, base, etc

Polypeptides

Linear chains of amino acids

Peptide Bonds

Between the amino group of one amino acid and the carboxyl group of another

Structure of a Protein

This determines the function of a protein (how it will work/behave)

Primary Structure of a Protein

The unique amino acid sequence of a protein. Amino acids are held together by peptide bonds

Secondary Structure of a Protein

When the polypeptide chain folds and forms hydrogen bonds between the repeating portions of amino acids; resulting from interactions between the repeating portions of amino acids. Hydrogen bonds can cause the polypeptide to from beta sheets or alpha helices

Beta Sheets

Flat

Alpha Helices

Coils

Tertiary Structure of a Protein

Depends on how the R groups interact with each other. Hydrogen bonds, hydrophobic interactions, disulfide bridges (S), and ionic bonds (base-Acid)

Quaternary Structure of a Protein

When some proteins consist of 2 or more folded polypeptide chains in close association or covalently bonded together. The R groups interact (Ex: Hemoglobin)

Denature

When a protein loses its shape and no longer functions correctly as a result of its environment

Nucleic Acids (CHONP)

Store heredity information

DNA

A polymer with a double stranded helix, has N-bases: A, G, C, Thymine, stores hereditary information, is longer/larger and sugar is deoxyribose

RNA

This is single stranded, has N-bases: A, G, C, and Uracil, carries information from DNA to ribosomes and sugar is ribose

Nucleotides

The monomers of DNA with a phosphate group (-), 5 carbon deoxyribose sugars, and a nitrogenous base

1’ Carbon

Holds the nitrogen base

3’ Carbon

Has a hydroxide that will bond with the P group of another nucleotide

5’ Carbon

Holds onto the phosphate group