AP Biology Units 1-3

Atoms are the

building blocks of matter

Atoms consist of

protons, neutrons, and electrons

An atom in the elemental state is always

neutral

If all the electrons are in the lowest available energy state, the atom is said to be in the

ground state.

When an atom absorbs energy, it moves to a higher level...

the excited state

Isotopes

atoms of one element that vary only in the amount of neutrons in the nucleus. They are the same chemically.

Radioisotopes

radioactive isotopes

Bond

a bond is formed when two atomic nuclei attract the same electrons

Energy releases when a bond is

formed

Energy is lost when a bond is

broken

Ionic Bonds

transfer of electrons, ions

gains electron - anion (A Negative ION)

loses electron - cation

Covalent Bonds

sharing electrons

molecules

single, double, and triple bonds

polar/non polar

Are diatomics polar or non polar?

non polar

Non Polar

electrons are shared equally between two identical atoms, balanced

Polar

electrons are shared unequally

Hydrophillic

water loving.

Hydrophobic

water hating

Miscibility

property of liquids to mix in all proportions

Hydrogen Bond

Bond between a hydrogen atom and either an oxygen, nitrogen, or fluorine.

Properties of Water

- high specific heat

- high heat of vaporization

- universal solvent

- strong cohesion tension

- less dense as a solid than a liquid

Capillary Action

combined forces of cohesion and adhesion

Surface Tension

the property that allows bugs to walk on water without falling through, caused by hydrogen bonding

Cohesion

the act of sticking together tightly, water is attracted to water

Adhesion

the act of repelling, water is attracted to something other than water

pH

measure of acidity and alkalinity in a solution

0-6 pH

acidic

7 pH

neutral

8-14 pH

basic/alkaline

The value of pH is the...

negative log of the hydrogen ion concentration in moles/liter

A pH of 1 is "x" times higher than a pH of 2

x = 10

pH of stomach acid

2

pH of acid rain

1.5-5.4

pH of human blood

7.4

Buffers

resist a change in pH

What is the most important buffer in the human blood?

Biocarbonate

Isomers

organic compounds that have the same molecular formula but different structures and different properties

Structural Isomers

differ in the arrangement of their atoms

Cis-Trans Isomers

only differ in the spatial arrangement around double bonds, which are not flexible like single bonds

Enantimoers

molecules that are mirror right images of each other

L -

left image, referring to enantimoers

D -

right image, referring to enantimoers

All the amino acids in cells are (L- or D-)

L-

Organic Compounds

contain carbon

Four classes of organic compounds

Carbohydrates, lipids, proteins, nucleic acids.

What does the body use carbohydrates for?

Fuel and as building materials

What do carbohydrates consist of?

Carbon, hydrogen, oxygen

The ratio of hydrogen to oxygen is always

2:1

The empirical formula of carbohydrates is always

CnH2O

1g of a carbohydrate will release "x" calories in a calorimeter

x = 4

What are the three classes of carbohydrates?

Monosaccharides, disaccharides, polysaccharides

Monosaccharides formula

C6H12O6

What monosaccharides are isomers of each other?

glucose, galactose, fructose

Disaccharides formula

C12H22O11

Definition of a disaccharide

two monosaccharides joined together, with the release of a water (H2O) molecule by dehydration

monosaccharide + monosaccharide -->

disaccharide + water

C6H12O6 + C6H12O6 -->

C12H22O11 + H2O

glucose + glucose -->

maltose + water

glucose + galactose -->

lactose + water

glucose + fructose -->

sucrose + water

Hydrolysis

the breakdown of a compound by adding water

What is hydrolysis the reverse of?

Condensation synthesis

Polysaccharides

are macro-molecules, polymers of carbohydrates

How are polysaccharides formed?

many monosaccharides join together by dehydration reactions

How many types of polysaccharides are there?

Four

Plant - structural polysaccharide

Cellulose - makes up the plant cell wall

Plant - storage polysaccharide

starch - amylase, amylopectin

Animals - structural polysaccharide

Chitin - makes up the exoskeleton in arthorpods

Where also can chitin be found?

in the cell wall of mushrooms

Animals - storage polysaccharide

glycogen - "animal starch"stored in liver and skeletal muscles

Lipids

fats, oils, waxes, steroids

All lipids are

hydrophoibc

Most lipids contain (structurally)

1 glycerol and 3 fatty acids

Glycerol is an

alcohol

Fatty acid

a hydrocarbon chain with a carboxyl group at one end

Saturated fats

come from animals. are solid at room temperature, contain only single bonds between carbon atoms

Unsaturated fats

come form plants, liquid at room temperature, good dietary fats, have at least one double bond formed by the removal of a hydrogen atom in the carbon chain

Tropical oils, such as coconut are more similar to

saturated fats

Steroids

are lipids that do not have the same general structure as other lipids, they consist of four fused rings

Types of steroids (3)

cholesterol, estradiol, testosterone

Lipid energy storange

1g of any lipid will release 9 calories per gram when burned in a calorimeter

Lipid structure

phospolipids, major component of the cell membrane

Lipid endocrine

some steroids are hormones

Phospolipids

a lipid where a phosphate group replaces one fatty acid

When phospolipids are added to water,

they self assemble into a bilayer

The head of the phospolipid is _____, while the tail is ________

hydrophilic,hydrophobic

picture : http://www.biologycorner.com/resources/lipidbilayer.gif

Proteins

complex, unbalanced macromolecules

Proteins carry out bodily functions, such as:

growth, repair, enzyme activities, signaling, movement, regulation

1g of a protein burned in a calorimeter releases __ calories

4

Proteins contain what elements?

Sulfur, phosphorous, carbon, oxygen, hydrogen, nitrogen

Amino acids

consist of a carboxyl group, amine group, and a variable (R) group all attached to a center, asymmetrical carbon atom

The R group ____ with each amino acid

differs

Dipeptide

molecule consisting of two amino acids connected by one peptide bond

Four levels of protein structure

primary, secondary, tertiary, quartenary

Primary

the unique, linear sequence of amino acids, the slightest change can have major consequences

Secondary

results from hydrogen bonding within polypeptide molecule, refers to how the polypeptide coils or folds into two distinct shapes

What are the two distinct shapes in a secondary protein structure?

Alpha helix and beta pleated sheet

Tertiary structure

intricate, 3D shape, imposed on secondary structure, determine the protein's specificity

What are the contributing factors in a tertiary sturcture?

hydrogen bonding between R groups, ionic bonding between R groups, hydrophobic interactions, Van der Waals interactions, disulfide bonds between cysteine amino acids

Quaternary structure

proteins that have more than one polypeptide chain

Fibrous proteins

proteins that exhibit either alpha helix, beta pleated sheet, or both