Chapter 2 : Chemical Principles

atoms

smallest compnent of a substance, it cannot be divide into

atomic number

number of proteins in the nucleus

Atomic mass

the total number of protons and neutrons in an atom approximant atomic mass

molecular mass

the sum of the atomic mass of all it atoms m

mole

a substance is a substance molecular md shown in grams ( used to relate the molecular level to the laboratory )

dalton( da)

the unit of molecular mass

chemicals reactions

the making or braking of bonds between atoms

ionic

an attraction between icons of opposite charges that hold them together to form molecules ( weak bonds are important for reactions with antigens & antibodies reactions )

covalent

a bond formed by two atoms that share one or more pairs of electrons, the most common bond responsible for holding atoms of most molecules in organisms

hydrogen

Very weak bonds in which a hydrogen atom is covalently bonded to one oxygen, nitrogen, serves a s bridges between different molecules or different parcens of the same molecule z9 ex, in protein & nucleic acids )

endergonic reaction ( endo = with in)

absorbes more energy than releases

exergonic reaction

energy is directed outward ( exo = out)

synthesis reaction

to put together /form new bonds

anabolism

synthesis reactionin iving organisms genrall called thi s. the combing of sugar molecules to form starch and amino acids and form protiens

catabolism

the name of the breakdown that occurs in living things ( ex, breakdown of sucrose ( sugar ) into simpler sugars , glaucous and fructose, during digestion

exchange reaction

bonds between A& B and C& dD are broken in a decomposition neew bonds are than formed between A& b and Between B& c in s synthesis process ( lego bricks )

reversable reaction

can happen because neither reactions are stable or are under certain conditions

inorganic compounds

definef as molecules, usally small & strucutal simple, which typically lack carboon, ionic bonds play as important role incldue water, molecular oxygen, carbon diciode, many salts ,acids and bases

organic compound

contains carbon anf hydroge are stucrally complex, carbin us a unique element due to is very versatikity carbon chains form the basis of many organic componds inliving cells including sugars , amico acids, and vitamins heald together mostly by covalent bonds

macromolecules

larger organic molecules including polysaccharides , proteins, & nucleic acids

water

nuterients are disoved in water, which facilitaies ther passage trough cell membrane , water is the mediem for most chemical reactions makes up 65% and 75% of every cell

Polar molecular

any molecular having an unequal distrbutation of charge

ionization/ dissocation

when inorganic salts are dissolved in water, they break apart into ions

acid

a substance that dissociates into one or more hydrogen ions and one or more negative ions ( a proton donor)

base

dissociates into one or more negativity charged hydroxide ions that can accept or combine with protons and one or more positive ions

Ph scale

reanges from 0 to 14 means potential ffor hydrogen

pH buffers

compounds that keep the Ph from changing drastically

carbon skeleton

specific groups of atoms that are most commonly involoved inchemical reaction anf re responsible for the charcteric chemical properties

macromolecules ( mano =large)

macromoleculea re usally polymers

carbohydrates

larger divers groups of organic compounds that include sugars & starches

Monosaccharides ( sasschar =sugar)

simple sugars, like glucose, pentons and hexose important for living things

disaccharides( di =two)

formed when two monosaccharides bond in dehydration

isomers (iso=same)

the molecules with the same chemical formula but different structures and properties

hydrolysis ( o

( op of dehydration ) when disacharides are broken into smaller smplar molecules when water is added

polysaccharides

consistes of ten or hundred of moosacarides joined through dehydration synthesis usally lak the harcteristic sweetness of sugars & are mot soluable in water

lipids ( lip = fat)

essential to the sturcure and formationof memebraes that seprate living vells from their emvierment, non polar molecules are in soluable

• primary functio is to form plasma membrane the supports the vell anf allows nutrients and wastes to pass in and out

complex lipid/phospholipids

build membranes, are essential to a cells survival has polar and non polar regions

steriods

structurral differen tfrom lipids

sterol ( alchol)

important constituite of plasma membranes of animal cell and of onr group of bacteria ) mycoplaysma ) also found in fungi anf plants seperate the fatty acids chains anf prevents packing

protiens

essentisl ingredents in all aspects of cell structure and function

• contraction of animal muscles

• cell structures

• antibodies

• hormones

enezymes

type of protien are chemicals that speed uo bio chemical reactions

amino acids

building blocks of proteins

• contain at least one carboxyl (-COOH) group

• amino (-NH2) group

• attached to an alpha- carbon ( Ca)

• attchated to the alpha- carbon is the side (R- group)

Peptide bond

The bonds between amino acids

Primary structure

(protein organization ) Unique sequences which amino acids link together to form a polypeptide chain `

Secondary structure

localized, repetitious twisting of folding of the polypeptide chain

tertiary structure

overall three- dimensional structure and a polypeptide chain. non reparative or predictable

quaternary structure

which consists of an aggregation of two or more individual peptide chains

denaturation

when proteins encounters a hostial environment in terms of temperature, pH, or salt concentrations may unravel and loses its shape

nucleotides

the structural units of nuclic acids

Stereoisomers

amino acids exist in two configurations, deignated by D and L

• amino acids in proteins are always L-isomers

• D-amino acids occasionally occur in nature for example in certain bacterial cells walls and antibiotics

simple proteins

contain only amino acids

conjugated proteins

combinations of amino acids with other organic or inorganic components

• named by their non-amino acid components