ch. 16 - amino acids, proteins, enzymes

what is the most abundant type of molecule present in our bodies

proteins

which food are proteins found in

eggs, nuts, dairy, etc.

what are the classes of proteins

structural, contractile, transport, storage, hormone, enzyme, and protection

what do structural proteins do

provide structure to our bodies

what do contractile protein do

muscle movement

transport protein function

move nutrients thorugh the body

storage protein function

store nutrients

hormone protein function

regulate metabolism and nervous system

enzyme protein function

catalyze (speed up) reactions

protection protein function

destroy foreign substances

what are amino acids

the building blocks of proteins (monosaccharides)

what are the components of the amino acid backbone

carboxylic acid, amine function groups, and an R group

at our body’s pH, _____’s ends are both ionized

amino acid

wyhich functional groups are characterized as nonpolar when considering nonpolar amino acids

alkanes and benzenes

can amino acids be slightly polar and still be considered nonpolar?

yes

which functional group is characterized as polar acidic when discussing polar amino acids

carboxylic acid

which functional groups are characterized as neutral when discussing polar neutral amino acids

alcohol, thiol, amide

which functional group is characterized as polar basic when discussing polar basic amino acids

amine

what are peptide bonds

when two amino acids link together

what are two connected amino acids called

dipeptide

what are three connected amino acids called

tripeptide

what are four connected amino acids called

tetrapeptide

what is the rule when naming peptide bonds

only keep the original name of the last amino acid, the rest before the last have to change their last syllable to -yl

which two factors give proteins their biological activity

shape and structure

what four categories determine the shape of a protein

primary structure, secondary structure, tertiary structure, quaternary structure

what does the primary structure entail

determined by the order of amino acids in the protein

moiety definition

an individual amino acid in a peptide or protein

proteins can contain tens to tens of thousands of amino acid ____ in many different orders

moieties

how does the secondary structure form

when the backbones of amino acids interact with each other via hydrogen bonds

what are the three most common secondary structures for proteins

alpha helix, beta-pleated sheet, and triple helix

how is tertiary structure determined

by how the protein folds

hydrogen bonds in tertiary structure R groups

interactions between OH, NH, and water (two polar)

salt bridges in tertiary structure R groups

interactions between ionized R groups (two ionic)

disulfide bonds in tertiary structure R groups

S-S bonds (two sulfur)

hydrophobic interactions in tertiary structure R groups

interactions of nonpolar amino acid R groups (two nonpolar)

what does the quaternary structure of proteins entail

how different protein units attach to one another

how do biologically active proteins form

when two or more tertiary structures attach to one another

the subunits of quaternary structures are held together by which bonds

hydrogen bonds, disulfide bonds, salt bridges, etc.

____ is made of four separate tertiary structures held together into one protein

hemoglobin

how do proteins get their structure?

DNA contains a series of instructions on what amino acids need to be strung toghether and when to allow the protein to fold

origin of DNA

nucleus of every cell

what happens when proteins are denatured

secondary, tertiary, or quaternary structure of the protein is disrupted

how can protein denaturation be caused

heat, acids or bases, organic compounds, heavy metals, and agitation

what temperature denatures proteins

over 50 degrees celsius

how do acids and bases denature proteins

disrupt salt bridges and hydrogen bonds

how do organic compounds denature proteins

disrupt hydrophobic interactions

how do heavy metals denature proteins

break disulfide bonds

how does agitation denature proteins

stretches peptide bonds and breaks hydrogen bonds and hydrophobic interactions

are most denaturation reversible or irreversible

irreversible

what are enzymes

catalysts made of protein

what do enzymes do

speed up chemical reactions in the body by lowering the activation energy of the reaction

how often does enzymatic activity occur outside the body

once every 27 seconds

when one molecule of the enzyme carbonic anhydrase is present for a reaction in our body, how often will the reaction occur

1 million times per second

list all the types of enzymes

oxidoreductase, transferase, hydrolase, lyase, isomerase, ligase

what does oxidoreductase do

catalyze redox reactions

what does transferase do

transfer substituents from one molecule to another

what does hydrolase do

hydrolyze (break apart) molecules using water molecules

what does lyase do

add or remove groups without using water

what does isomerase do

rearrange atoms in a molecule

what does ligase do

combine molecules together using energy

what reaction does this figure display

oxidoreductase

what reaction does this figure display

transferase

what reaction does this figure display

hydrolase

what reaction does this figure display

lyase

what reaction does this figure display

isomerase

what reaction does this figure display

ligase

substrate definition

the molecule(s) that react in the enzyme

active site definition

the location in the enzyme molecule where the reaction takes place

enzyme-substrate complex definition

the combination of the enzyme and substrate before the reaction takes place

cofactor definition

metal ions or vitamin derivatives that make an enzyme function

how do enzymes work 1st step

enzyme has to bind to the substrate

how do enzymes work 2nd step

once bound, reaction can happen or they can split apart without a reaction

factors affecting enzymatic activity

temperature, pH, and inhibitors

temperature optimal for enzymatic activity

37 degrees celsius

what happens to enzymes at colder temperatures

they work slower

what happens to enzymes at higher temperatures

they become denatured

which conditions in the body would cause significant temperature change that would hinder enzymatic activity

hypothermia and high fever

what is the optimal pH for enzymes to work

depends on where enzyme is active in the body

what happens if the pH is too high or low for enzymes

enzyme is denatured

what is an inhibitor

a molecule that prevents an enzyme from reacting

what are the four different types of inhibitors

competitive reversible, competitive irreversible, noncompetitive reversible, and noncompetitive irreversible

what occurs in competitive inhibition

inhibitor has a similar shape to substrate and will fit into the active site without reacting

how to restore activity from a competitive inhibitor

concentration of substrate must be increased

what occurs in noncompetitive inhibition

bind to another part of the enzyme and cause active site to change in shape to no longer recognize the substrate

how do you regain activity from a noncompetitive inhibitor

inhibitor must be chemically removed

what occurs in an irreversible inhibition

inhibitor forms a covalent bond with amino acid in the active site or other place in the enzyme, bond cannot be broken by the body, so the enzyme is permanently inhibited

what is an example of an irreversible inhibition

antibiotics

what is an example of a competitive inhibitor

penicillin

what is penicillin

a competitive inhibitor for an enzyme in bacteria that makes a compound necessary for bacteria to expand their cell walls