ch. 2 chemical principles

atoms

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

element

a substance that cannot be broken down into other substances by chemical reactions (all have the same number of protons)

isotopes

element with the same number of protons but a different number of neutrons

compound

molecule that contains at least two different kinds of elements in a fixed ratio

covalent bond

chemical bond formed by two atoms sharing one or more pairs of electrons

ionic bonds

an attraction between ions of opposite charge that hold them toegther to form a stable molecule

hydrogen bond

weak bonds formed by attraction of positively charged hydrogen atom to a negatively charged atom.

organic

c to c or c to h bond

inorganic

do not contain c to c or c to h bond

typically composed of elements otheer than carbon

carbohydrates

large and diverse group of organic compounds that include sugar and starches

general formula for carbohydrate

CH2O

monosaccharide

single sugar molecule

disaccharide

two monosaccharides connected through dehydration synthesis

Polysaccharides

the polymers of sugars have storage and structural roles

starch

a storage polysaccharide of plants

cellulose

major component of plant cell walls

chitin

found in exoskeleton

simple lipid

contain glycerol and fatty acid

saturated fats

do not have c-c double bonds

unsaturated fats

have one or more c-c double bonds

proteins

enzymes, transporter
proteins, toxins, contraction,
movement, hormones, cell components
etc.

amino acids

building blocks of
proteins

peptide bond

Link Amino Acids Together in Proteins

primary structure

the unique sequence in which the amino acids are linked together to form a polypeptide

secondary structure

repetitious twisting or folding of the poly peptide chain which forms helix or sheet

tertiary structure

refers to overall three dimensional structure of polypeptide chainq

quaternary structure

two or more individual polypeptides joining to form a protein

four bases of DNA

adenine

thymine

guanine

cytosine

purine

guanine and adenine

pyrimidine

thymine cytosine and uracil

char gaffs rule

a=t, g=c

RNA four bases

adenine

uracil

guanine

cytosine

DNA

double stranded

RNA

single stranded