Full AP Bio

in depth cram review ap biology

Elements

Substances that cannot be broken down into simpler substances by chemical means.

Total natural elements

There are 92 naturally occurring elements recorded in these notes.

Four main elements of life

Oxygen (O), carbon (C), hydrogen (H), and nitrogen (N), making up 96% of the mass of living things.

Oxygen symbol

$$O$$

Carbon symbol

$$C$$

Hydrogen symbol

$$H$$

Nitrogen symbol

$$N$$

Secondary elements in organisms

Calcium (Ca), phosphorus (P), potassium (K), sulfur (S), sodium (Na), Chlorine (Cl), and magnesium (Mg).

Calcium symbol

$$Ca$$

Phosphorus symbol

$$P$$

Potassium symbol

$$K$$

Sulfur symbol

$$S$$

Sodium symbol

$$Na$$

Chlorine symbol

$$Cl$$

Magnesium symbol

$$Mg$$

Weight of secondary elements

These elements make up most of the remaining 4% of a living thing's weight.

Trace elements

Elements required by an organism only in very small quantities, such as iron (Fe), iodine (I), and copper (Cu).

Iron symbol

$$Fe$$

Iodine symbol

$$I$$

Copper symbol

$$Cu$$

Atom

The smallest unit of an element that retains its characteristic properties; the building block of the physical world.

Subatomic particles

Protons, neutrons, and electrons.

Protons

Subatomic particles located in the core of an atom carrying a positive charge ($+$).

Neutrons

Subatomic particles located in the core of an atom carrying no charge (neutral).

Electrons

Subatomic particles located in electron shells outside the nucleus carrying a negative charge ($-$).

Nucleus

The core of an atom where protons and neutrons are packed together.

Electron shells

The region outside the nucleus where electrons are located.

Electron mass

Considered massless because they are much lighter than protons and neutrons.

Electrically neutral atoms

Atoms that possess the same number of protons and electrons.

Isotopes

Atoms with the same number of protons but different numbers of neutrons in the nucleus.

Radioactive isotopes

Isotopes that decay over time.

Chemical compound

A substance formed when two or more individual elements are combined.

Chemical bonds

The forces holding together the atoms of a compound.

Ionic bonds

Bonds formed between metal and non-metal atoms.

Covalent bonds

Bonds formed between non-metal atoms.

Structure of a water molecule

Consists of two hydrogen atoms joined to one oxygen atom.

Polarity in water

Unequal sharing of electrons where hydrogen has a partial positive charge and oxygen has a partial negative charge.

Partial positive charge symbol

$$\delta+$$

Partial negative charge symbol

$$\delta-$$

Polar molecule

A molecule having partially positive and partially negative charges.

Hydrogen bonds (H bonds)

Attractive forces between the partial positive end of one polar molecule and the partial negative end of another.

Individual strength of H bonds

Individually weak, but strong when they exist in large numbers between water and other substances.

Water as a solvent

Capable of dissolving polar substances like glucose, salt, and amino acids by forming hydrogen bonds.

Cohesion

The tendency of water molecules to stick to each other due to hydrogen bonding.

Adhesion

Water molecules forming hydrogen bonds with a containing tube or surface.

Capillary action

The combined phenomenon of cohesion and adhesion allowing water to rise in thin vessels (roots, trunks).

Surface tension

A property resulting from cohesion where the surface of water resists being broken, allowing light things to stay on top.

High heat capacity of water

The ability of water to absorb and release a lot of heat without drastic changes in its temperature.

Expansion on freezing

When solidifying into ice, hydrogen bonds cause water to expand into a rigid repeating structure.

Density of liquid water vs. ice

Liquid water is slightly more dense than solid water, allowing ice to float.

Biological impact of floating ice

Allows life to survive in lakes and streams underneath the top layer of ice.

Acidic solution

A solution containing a high concentration of $H^+$ ions.

Basic (Alkaline) solution

A solution containing a high concentration of $OH^-$ ions.

pH definition

The measure of acidity of a solution calculated as $pH = -\log[H^+]$.

Relationship of pH to $H^+$ions

An increase in $H^+$ ions causes a decrease in the pH value.

Organic compounds

Chemical compounds containing a skeleton of carbon atoms surrounded by hydrogen atoms.

Inorganic compounds

Molecules that do not contain carbon atoms.

Four types of organic compounds

Carbohydrates, proteins, lipids, and nucleic acids.

Monomers

Repeating building blocks that join to form chains called macromolecules.

Carbohydrate elements

Consist of $C$, $H$, and $O$.

Protein elements

Consist of $C$, $H$, $O$, and $N$ (and sometimes $S$).

Lipid elements

Consist of $C$, $H$, and $O$ (and sometimes $P$ in phospholipids).

Nucleic acid elements

Consist of $C$, $H$, $O$, $N$, and $P$.

Carbohydrate formula (proportion)

$C_n H_{2n} O_n$ (Simplified as $(CH_2O)_n$).

Monosaccharides

The simplest sugars that serve as an energy source for cells.

Glucose formula

$$C_6 H_{12} O_6$$

Fructose

A six-carbon monosaccharide often found in fruits with the formula $C_6 H_{12} O_6$.

Straight-chain vs Ring form

The two physical forms glucose and fructose can take, with ring being common in solution.

Disaccharide

A sugar formed when two monosaccharides combine via a condensation reaction.

Condensation reaction

A reaction combining two molecules that produces one molecule of water.

Glycosidic linkage

The bond formed between two monosaccharides to create a disaccharide.

Maltose formation

Two glucose molecules combined through a condensation reaction.

Sucrose

A common disaccharide known as table sugar.

Lactose

A common disaccharide found in milk and dairy products.

Hydrolysis

A reaction where water is added to break the bond between two monomers in a polymer.

Polysaccharides

Carbohydrates formed by many repeated units of monosaccharides in branched or unbranched chains.

Starch

A sugar storage molecule in plants made of $\alpha$-glucose.

Glycogen

A sugar storage molecule in animals made of $\alpha$-glucose.

Cellulose

A structural polysaccharide in plant cell walls made of $\beta$-glucose.

Polysaccharide solubility

They are not soluble in water and thus do not affect osmotic balance.

Amylose

A straight-chain $\alpha$-glucose polymer used for energy storage.

Amylopectin

A branched $\alpha$-glucose polymer used for energy storage where branches can be easily removed to release energy.

Microfibrils

Structures formed by cellulose providing structural support in plants.

Amino acids

The building blocks of proteins containing carbon, hydrogen, oxygen, and nitrogen.

Parts of an amino acid

Amine group ($-NH_2$), carboxyl group ($-COOH$), a hydrogen ($H$), and an R-group around a central carbon.

Amine group

$$-NH_2$$

Carboxyl group

$$-COOH$$

R-group (Side chain)

The part of the amino acid that varies and determines its chemistry (polar, non-polar, charged).

Number of common amino acids

There are 20 different amino acids commonly found in proteins.

Glycine

The simplest amino acid, where the R-group is a single hydrogen atom ($H$).

Hydrophobic amino acids

Non-polar side chains that repel water and cannot dissolve easily.

Hydrophilic amino acids

Polar or charged side chains that attract water and can dissolve easily.

Asp (Aspartic Acid)

An amino acid with a polar, negatively charged side chain.

Lys (Lysine)

An amino acid with a polar, positively charged side chain.

Dipeptide

A molecule formed when two amino acids join via a condensation reaction.

Peptide bond

The specific name for the bond connecting two amino acids.

Polypeptide

A group of amino acids joined together in a long chain.

Protein

A organic compound consisting of one or more polypeptide chains twisted and folded into a specific 3D structure.

Primary structure

The unique sequence of amino acids in a polypeptide chain.

Secondary structure

The coiling or folding of a polypeptide chain into $\alpha$-helices or $\beta$-sheets due to hydrogen bonding.