Chapter 2: Molecular Interactions

physiology

physiology

the study of normal functioning of a living organism and its component parts

pathology

occurs when normal function is disrupted and a disease state or condition forces the internal environment out of balance

ion

when an atom gains or loses one or more electrons and it acquires an electrical charge

anion

gains an electron (a negative charge)

cation

loses an electron (a positive charge)

ligand

any molecule or ion that binds to another molecule

polar molecules

molecules that develop regions of partial positive and negative charge (water)

nonpolar molecules

have electrons distributed to evenly that there are no regions of partial positive or negative charge (carbon)

water H2O

universal solvent. can dissolve many different substances in large amounts

hydro

water

hydrophilic

water loving

hydrophobic

water fearing

mixture

consists of two or more compounds combined but are not chemically bound

solution

homogeneous (parts of the same kind) mixture where the molecules are evenly distributed and will not separate upon standing

solvent

the dissolving substance

solute

the substance which is being dissolved (sugar glucose, small protein molecules, carbon dioxide and oxygen)

suspension

heterogeneous (parts of different kind) mixture where the particles will separate out upon standing

colloid

heterogeneous mixture where the particles remain suspended, but do not separate upon standing (jello-large protein molecules remain evenly distributed in the water)

acid

can donate a hydrogen ion into solution

base

can accept hydrogen ions from a solution

salt

is a balanced combination of an acid with a salt

pH scale

monitors the acidity and alkalinity of a solution based on how many ions have been released into the solution. the higher the H concentration the more acid the solution. the higher the OH concentration, the more basic the solution

buffers

resist pH change and help prevent such changes (bicarbonates, supplement)

cellular fluid compartments

1. intracellular - within

2. extracellular - outside

3. interstitial - between circulatory and cells (in tissue)

carbohydrates

composed of carbon(C), hydrogen(H), and oxygen(O), CHO abbreviation which when combined in various combinations are referred to as Saccharides. these are the most abundant biomolecules

simple carbohydrates

small molecules of sugar

monosaccharides

composed of a single sugar

glucose

circulates in the blood, storable form in the liver

fructose

from fruits or honey

galactose

mainly comes from the digestion of milk sugar (lactose)

disaccharides

composed of two sugars

sucrose

glucose + fructose (table sugar, brown, powdered, cane or beet)

lactose

glucose + galactose (milk sugar), aids in the absorption of Calcium and Phosphorus, encourages the growth of useful intestinal bacteria

maltose

glucose + glucose, often used as a synthetic sweetener

complex carbohydrates

large molecules of sugars (polysaccharides) combined with starch which together provide energy and dietary fiber

starch

found in grains, legumes (beans), and some fruits in small amounts, breakdown slowly and supply energy over a longer period

glycogen

found in animal muscle tissue, crucial in body metabolism and energy balance, constantly being broken down into glucose

stored in liver

dietary fiber

polysaccharides

insoluble

doesn’t dissolve in water

soluble

dissolve or absorb water

lipids

organic substances of a fatty nature including: fats, oils, waxes, and other fat-related compounds such as cholesterol

glycerides

formed from glycerol with one, two, or three fatty acids attached

fatty acids

the building blocks of triglycerides (glycerol + 3 fatty acids)

essential fatty acids

those that are necessary in the diet

saturated fatty acids

capable of holding all the hydrogen molecules - from meats, dairy, eggs, and tropical oils

unsaturated fatty acids

essential fatty acids, capable of holding some hydrogen ions, liquid at room temperature

monounsaturated fatty acids

have room to hold one more hydrogen molecule - from olives, olive oil, peanuts, almonds, avocados

polyunsaturated fatty acids

have room to hold multiple hydrogen molecules - vegetable oils, corn, soybean, fish oils

omega 3

lowers bad cholesterol while keeping good cholesterol stable and reduces tissue inflammation - fish like salmon, sardines, tuna, as well as flax seeds, walnuts

omega 6

lowers cholesterol when eaten in place of saturated fat, but it lowers both bad and good cholesterol as well as increases inflammation - corn oils, sunflower, safflower

foods containing both omega 3 and 6

walnuts, tofu, wheat germ, soybean oil

sterols

a subgroup of steroids (sex hormones) that are made by plants and animals and are vital in the stabilization of the cell membrane, cholesterol specifically acts in this capacity

amino acids

building blocks of proteins, compounds containing nitrogen

peptides

small chains of amino acids

polypeptides

longer chains amino acids

proteins

long chains of amino acids

fibrous

found as pleated sheets or in long chains of helices that are insoluble in water and form structural components of cells and tissues

globular

have amino acid chains that fold back on themselves to create a complex tertiary structure containing pockets, channels, or protruding knobs. soluble in water and act as carriers

quaternary structure

several protein chains associating with one another (hemoglobin)

indispensable amino acids

necessary in the diet and cannot be left out because the body cannot manufacture them in sufficient quantities or at all

conjugated proteins

are protein molecules combined with another kind of biomolecule, both are important components of cell membranes

lipoproteins

transport lipids in the blood stream, a water-soluble carrier molecule consisting of wrapping a fat droplet in a thin protein coat that is hydrophilic

glycoproteins

proteins combines with a carbohydrate

nucleotides and nucleic acids

function in the storage and transmission of genetic information and energy

DNA - deoxyribonucleic acid

adenine, guanine, cytosine, thymine (double helix, A-T, G-C)

sequence of specific amino acid building blocks that instruct how different proteins are to be constructed

RNA - ribonucleic acid

adenine, guanine, cytosine, uracil (single strand)

sequence of specific amino acid building blocks located almost entirely in the cytoplasm

nucleus

control center of the cell containing the nucleolus which in turn contains the cells genetic material (DNA) which directs the cell’s activities

transcription

the DNA molecule unwinds and information from DNA is transferred to mRNA (copying)

translation

once the mRNA attaches to the ribosome, tRNA comes into the picture to transfer amino acids to the ribosomes where they will bound together by enzymes in an exact sequence specified by the gene

isoforms

closely related proteins with similar function, but different affinity for ligands

cofactors

required for ligand binding

proteolytic activation

converts inactive to active form by removing part of molecule (digestive enzymes)

competitive inhibitor

competes with ligand by binding reversibility to site

irreversible inhibitor

binds to binding site and cannot be removed

allosteric modulator

binds to protein away from binding site and changes activity by inhibition or activation

covalent modulator

binds changing activity

pH and temperature

alters the 3D shape by disrupting H or subunit to subunit bonds:may be irreversible if protein denatures

enzymes

biological catalysts that speed up chemical reactions

membrane transporters

movement between intracellular and extracellular compartments

signal molecules

ligands

binding proteins

found mostly in the extracellular fluid, bind and transport molecules throughout the body

immunoglobulins

fight foreign invaders

regulatory proteins

turn cell process on and off or up and down

recombinant DNA technology

DNA that contains information from two different species of organism which can then be transferred to the offspring (transgenic)

denaturation

the disruption and possible destruction of both secondary and tertiary structures (protein)

heat

can be used to disrupt hydrogen bonds and non-polar hydrophobic interactions

alcohol disrupts hydrogen bonding

hydrogen bonding occurs between amide groups in the secondary protein structure

acids and bases disrupts salt bridges

the denaturation reaction on the salt bridge by the addition of an acid results in a further straightening effect on the protein chain

heavy metal salts

denature proteins in much the same manner as acids and bases