APBio Unit 1 Chem. of Life

Macromolecules

Molecules composed of thousands of atoms: the four main classes being carbohydrates, lipids, prteins, and nucleic acids

Polymer

Chainlike molecules, consisting of many similar or identical building blocks linked by covalent bonds.

Monomer

Make up polymers: connected by covalent bonds.

Dehydration Synthesis

(Condensation Reaction): Covalent bonds which connect monomers have distinct functions: One monomer provides a hydroxyle group and the other provides a hydrogen, creating water (as a biproduct) and a bond between the monomers.

Hydrolysis

Adding water to reverse dehydration synthesis, so the polymer recieves a hydrogen atom and a hydroxyl group

Carbohydrates

A macromolecule made up of C, H and O, with a 2:1 ratio between the hydrogen and oxygen.

Monosaccharides

Simple sugars with 1 ring: Provides immediate energy, classified by the amount of carbons

Disaccharides

Double sugars with 2 rings

Polysaccharides

Polymers, with many rings, joined by glucosidic linkages. Acts as an energy storage macromolecule, building materials for cells or whole organisms

Maltose

A disaccharide formed by joining the two glucose molecules: found in malt sugar

Sucrose

A disaccharide formed by joining glucose and fructose, major form of sugars in plants: found in table sugar

Lactose

A disaccharide formed by joining glucose and galactose. People who lack the enzyme to digest this sugar are "intolerant"

Glucosidic Linkages

the bond that bonds polysaccharides

Starch

During photosynthesis: glucose is a biproduct that is stored in plastids and chloroplasts

Cellulose

Made up cell walls of plants, using beta rings

Glycogen

An animal polysaccharide. Human produces excess sugar, highly branched. Humans and vertebrates store this in the liver and muscles

Chitin

Makes up the exoskeleton of pill bugs; extremely strong, contains nitrogen-containing appendage on each glucose. Structural support for the cell walls of many fungi.

Lipids

Literally no affinity for water (hydrophobic), nonpolar molecules. Have C, H and O, but not in a 2:1 ratio.

Triglycerides

(Fats): Store large amounts of energy, made up of 1 glycerol + 3 fatty acids -> 1 fat + 3 water molecules. Functions as energy storage, to cushion vital organs, and insulation.

Ester Linkage

Joins 3 fatty acids to a glycerol, creating a triacylglycerol

Saturated fatty acids

Fatty acids with single bonds, hydrogen at every possible position, a straight shape, from an animal source. Solid at room temperature.

Unsaturated fatty acids

Fatty acids with double and single bonds, without hydrogens at every possible position, a kinked/bent shape, from a plant source. Liquid at room temperature.

Phospholipid

2 fatty acids attached to a glycerol, with a phosphate group in the 3rd position. Have both hydrophobic and hydrophilic bonds

Steroid

A type of phospholipid: A carbon skeleton with 4 fused carbon rings, which are closely interlocked. ex., cholesterol

Proteins

Built up of 20 types of amino acids, which can unravel or denature in response to changes in pH, salt concentration, and temperature because they disrupt the bonds between parts of the protein

Primary Structure

The unique sequence of amino acids, determined by DNA. Changing this affects a protein's conformation and ability to function.

Secondary Structure

Results from hydrogen bonds at regular intervals doing the polypeptide backbone, typically developed as an alpha helix or a beta pleated sheet.

Tertiary Structure

The protein has folded up upon itself, held together by hydrogen bonds, ionic bonds, Van der Waals reactions, or disulfide bridges

Quarternary structure

Union of 2+ polypeptide subunits

Enzymes

Speeds up the rate of reactions, but are not consumed by the reaction. Lowers the activation energy of a reaction, and makes it easier to perform these reactions.

Substrate

A reactant that binds to an enzyme

Active Site

A pocket/groove on the surface of a protein on the surface of the protein into which the substrate fits. The substrate is held to this area through weak interactions, such as hydrogen bonds or Van der Waals.

Induced Fit Hypothesis

As the substrate binds, the enzyme changes shape leading to a tighter induced fit, bringing chemical groups into position to catalyze the reaction.

Cofactors

Non-protein factors, helping the enzyme fit substrates. ex: zinc, iron, copper

Competitive Inhibitors

Blocks the active site from having a substrate meet. Acts as a feedback mechanism

Noncompetitive inhibitors

Blocks the substrates at a place away from the active site.

Allosteric Enzymes

Enzymes that can change their shape: one shape is active (reaction occurs) and one is inactive (reaction doesn't occur)

Nucleic Acids

An organic compound made up of a pentose sugar, phosphate, and nitrogen base. The three types are DNA, RNA and ATP

Ribonucleic acid (RNA)

Many types of instructional nucleic acid, which is directed by DNA and contributes to protein production

Deoxyribonucleic acid (DNA)

Provides the genetic coding for organisms and directs RNA synthesis: synthesized through dehydration synthesis, connecting the sugar of one nucleotide to another with a strong phosphodiester.

Nucleotide

The building blocks of nucleic acids

Pentose sugar

Deoxyribose and ribose; a building block of nucleic acids

Phosphate

Makes DNA and RNA charged; a building block of nucleic acids

Nitrogen base

Adenosine, Thymine, Guanine, Cytosine, Uracil (RNA); building blocks of DNA. A+T are always together, and G+C are always together based on their properties. U is only found in RNA.

Purines

Adenosine, Guanine; have a double ring,

Pyrimidines

Thymine, Cytosine, Uracil; Single ring

Phosphodiester Link

The bond between a sugar and a phosphate.

Element

a substance that cannot be broken down to other substances by chemical reactions

Atom

smallest unit of matter that still retains the properties of an element

Atomic number

number of protons, which is unique to that element

Electron Shells

where electrons are found; outside the nucleus

Valence Electrons

electrons in an atoms outermost shell, shared in a covalent bond. Given/Taken in an ionic bond.

Covalent Bond

sharing a pair of valence electrons by two atoms

Non-polar Covalent Bond

electrons are shared equally because the two atoms have the same electronegativity

Polar Covalent Bond

One atom is bonded to a more electronegative atom, the electronsof the bond are not shared equally

Ionic Bond

Cations and Anions attract together because of opposite charge

Ion

a charged atom (or molecule)

Hydrogen Bonds

non-covalent attraction between a hydrogen and an electronegative atom

Reactants

Substance present at the start of a reaction

Products

Substance present at the end point

Cohesion

The attraction of one substance to itself.

Adhesion

The attraction of a substance to a different substance.

Surface Tension

The force exerted along the surface of a fluid that causes it to "bead up" and form into drops.

Buffer

A solution that will resist changes in pH when small quantities of an acid or base are added to it.

Proton

A positively charged particle, makes up a part of the atomic nuclei.

Neutron

A particle with lacking charge that makes up part of the atomic nuclei.

Electron

A negatively charged atomic particle.

Hydrophilic

Soluble in water. These substances are either polar or ionic. They are attracted to water.

Hydrophobic

Type of molecule, typically nonpolar, and therefore does not interact easily with water

Molecule

groups of two or more atoms held together by chemical bonds

Solution

Formed when substances (solute) dissolves in other substances (solvent).

Solvent

the dissolving medium in a solution

Solute

substance that dissolves

pH Scale

0 (strong acid) to 14 (strong base) 7 is neutral

Acid

A compound that releases hydrogen ions (H¹⁺) when dissolved in water, having a pH of less than 7.

Atomic mass

The weighted average of the masses of the isotopes of an element.

Base

A compound that releases hydroxide ions (OH¹⁻) when dissolved in water, having a pH of more than 7.

Enantiomers

molecules that are mirror images of each other

Functional Groups

atoms or groups of atoms that give a family of organic compounds its characteristic chemical & physical properites

Heat

The energy associated with the motion of particles in a substance is called

Isomers

compounds that have the same molecular formula but different structures

Isotope

same number of protons, different number of neutrons

Orbital

a region of space around the nucleus where an electron is likely to be found

Radioactive Isotope

unstable and will decay into other elements

Specific Heat

A measure of the amount of heat needed to raise the temperature of 1 gram of a substance by 1 degree C

Temperature

A measure of the average kinetic energy of the particles in a sample of matter.

Van Der Waals

Relatively weak intermolecular force