Unit 1 Campbell 12th Edition

Trace elements

elements needed only in minute quantities

ex: Fe, I, Zn

Essential elements

elements needed to live a healthy life and reproduce (humans have 25)

What is the approximate mass of protons and neutrons

1 dalton/amu

Radioactive isotopes

an isotope where the nucleus decays spontaneously, releasing energy and particles

Half-life

the time it takes for half to the parent isotope to decay

Energy

the capacity to cause change

Potential energy

energy possessed because of location or structure

Inert elements

Elements with a full valence shell, so chemically unreactive

Orbital

the 3D space where an electron mostly resides

Covalent bond

sharing a pair of valence electrons

Compound

combination of two or more different elements

Molecule

two or more atoms

Nonpolar covalent bond

electrons pulled relatively equally; low electronegativity

Polar covalent bond

electrons not shared equally

Ionic bond

ions attracting each other

Hydrogen bond

noncovalent attraction between H and electronegative atoms

Chemical reaction

the breaking and making of chemical bonds, causing a change in composition of matter

Reactants

starting materials

Products

resulting materials

4 properties of water

cohesion, temperature regulation, floating on ice, universal solvent

Cohesion

attraction of molecules to molecules of the same kind

Surface tension

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

Adhesion

the clinging of one substance to another

Kinetic energy

the energy of motion

Temperature

average kinetic energy of molecules in a body of matter

Thermal energy

total kinetic energy of a body of matter (depends on volume)

Heat

thermal energy transfer from one body to another

calorie

amount of heat to raise 1g of water by 1 C

1 calorie is how many Joules

4.184 J

Hydrophilic

affinity for water

Hydrophobic

can't form hydrogen bonds, so repels water

Organic compound

a compound with carbon

Isomer

compounds with same formula but different structure

structural isomers

isomers that differ in covalent arrangements of atoms

cis-trans isomers

atoms have different spatial arrangement caused by double bonds

cis isomer

same groups on same sidd

trans isomer

same isomers on opposite sides

enantiomers

mirror images of each other due to asymmetric carbon

hydroxl group

—OH

• are polar

• forms H bonds with water

• helps dissolve compounds

carbonyl group

>C=O

carboyxl group

—COOH

• acts as an acid

amino groups

—NH₂

• acts as an base

sulfhydryl groups

—SH

• can form cross-links if reacts with each other, stabilizing proteins

phosphate groups

—OPO₃²⁻

• allows a molecule to react with water releasing water

methyl groups

—CH₃

• affects the expression of genes when bonded to DNA

• hydrophobic

Macromolecule

large carbohydrates, proteins, and nucleic acids made of polymers

Monomer

building block of polymer

Polymerization

process where cells make polymers

Condensation reaction

connects monomers

Dehydration reaction

forms bond between monomers by removing water

Hydrolysis

breaks down polymers by adding water

Carbohydrate

macromolecule made of polysaccharides

Monosaccharide

monomer of carbs

• have CH₂O formula

• have carbonyl group

• short term fuel source

glycosidic linkage

joins monosaccharides by dehydration reaction

polysaccharides

polymers with hundreds to thousands of monosaccharides

ex:

starch to store glucose

cellulose in cell walls

Lipids

hydrophobic but not polymers

fats

glycerol and 3 fatty acids

main function is energy storage

fatty acid

have long carbon skeleton and carboxyl end

ester linkage

bonds hydroxyl and carboxyl

ex: fatty acid to glycerol

saturated fat

doesn't have double bonds, so more hydrogen

solid at room temp

unsaturated fat

has cis double bonds that causes kinks

compacts less, so liquid at room temp

trans fat

fat with trans double bonds

Phospholipid

glycerol, 2 fatty acids, phosphate group, and polar attachment

hydrophilic head and hydrophobic tail

Steroid

4 fused carbon rings with chemical groups attached

Protein

made from one or more polypeptides with unique shape

amino acid

monomer of protein

has amino group, carboxyl group, H, and side chain

peptide bond

formed by dehydration reaction between amino and carboxyl

polypeptide

polymer of protein

has N terminus and C terminus

Primary structure

linear chain of amino acids

shows alpha helices and beta sheets

secondary structure

amino acids can helix or pleat

caused by hydrogen bonds between polypeptide backbone

tertiary structure

3d shape from secondary structure

stabilized by side chain interactions

Hydrophobic interaction

hydrophobic amino acids cluster at protein core

polar and charged side chains bond to give protein its shape

quaternary structure

two or more polypeptides together

Denaturation

protein unravels and loses native shape

Nucleic acids

macromolecules made from nucleotides

DNA

has 2 antiparallel polynucleotide strands in double helix

nucleotide

made of pentose, nitrogenous base, and 1-3 phosphate groups

free end with phosphate to 5’ carbon is 5’

free end with hydroxyl to 3’ carbon is 3’

phosphodiester linkage

phosphate linked to two nucleotides

causes sugar phosphate backbone

nucleoside

nucleotide without phosphate