bio chem - lippncott

A-

it is the ionized form of a weak acid (already have away H+). also known as the conjugate base.

H+

the proton. can be received or donated.

Ka

acid dissociation constant and it tells how willing is the acid to give away its H+

large Ka

very little HA is left. strong acid

small Ka

almost no H+ is released. weak acid

the equation for Ka

Ka = products / reactants

products

H+ and A-

reactant

HA

Ka becomes BIG

lots of products (H+ and A-) = strong acid

Ka becomes SMALL

few products (little H+ and A-) lots of HA = weak acid

small pKa

large Ka

large pKa

small Ka

HA

the acid is still holding H+

solution becomes less acidic (higher pH)

most acids have already released H⁺

solution is more acidic (lower pH)

most acids are still holding onto H⁺

strong acid

a parent who lets go easily → lots of free H⁺ → high Ka, low pKa

weak acid

keeps holding the child's hand → very few free H⁺ → low Ka, high pKa

proteins

most abundant and versatile molecules in the body

enzymes

speed up chemical reactions