Midterm Review

comes from protons and neutrons- 99.5% of mass is in nucleus

characteristic number or protons

oxygen, carbon, hydrogen and nitrogen

sodium, potassium, calcium, chorine, magnesium, phosphorous, sulfur

neutrons+protons

atoms with same atomic number but different mass number

certain unstable and high energy isotopes release energy in the form of radiation (radioactive decay) to assume a more stable form

liquid mixed with solid, solids will settle

ex- blood

solids not visible with naked eye

particles are suspended and do not settle

ex- milk

solid, liquid, gas mixed with a liquid

component dissolves

water is most important solvent

ex- glucose and water

amount of solute present

an energy relationship between atoms (attractive forces)

2 or more atoms of different elements bonded, called molecules of a compound

large compounds composed of many atoms

outermost shell ( electron ring)

electrons in outermost electron ring (valence shell)

atom is most stable when it has 8 electrons in valence shell (dont forget about duet rule though)

electrons are transferred between a metal and a nonmetal (exception is hydrogen)

sharing electrons between two or more nonmetals (much more stable than ionic)

two nonmetals in a molecule have same electronegativity and tug on electrons with the same force until electrons are shared equally

nonmetals of different electronegativities pull on electrons and the nonmetal that is more electronegative "wins" but only partially

winning atom isn't strong enough to completely take the electrons, they are just shared unequally

two opposite poles- polar covalent bonds

one side is slightly negative

one side is slightly positive

potential- stored energy

kinetic- energy in motion

chemical energy

electrical energy

mechanical energy

they may all be potential or kinetic

require chemical, electrical or mechanical energy from another source, produces more energy than reactants because energy was invested

reactants have more energy than product, excess energy stored in reactants released during reaction

reactants become more stable when energy is released

also called decomposition breakdown

larger substance breaks down (required to break down foods, break down old or damaged cells, defend body against invading organisms)

AB-> A+B

one or more atoms from reaction are exchanged for another, bonds are broken and formed

AB+CD-> AD+BC

electrons are exchanged instead of atoms

reactants that lose electrons = oxidized

reaction that gains electrons= reduced

generally exergonic and release lots of energy

reactions that create new chemical bonds (synthesis reactions)

A+B-> AB

activation energy

concentration

temp

properties of reactants (size/state)

presence/absence of catalyst ( substance that lowers activation energy)

macromolecules

speed up reactions by lowering activation energy

specific to substrates

do not alter chem reaction

are not altered in reaction

"induced fit" mechanism

acids

Hydrogen ion have one lone proton in nucleus

base (alkali)

keep pH in check

consist of weak acid and corresponding anion

major buffer in body- carbonic acid-bicarbonate ion buffer system

blood pH falls below 7.35

loss of hydrogen ions, causes blood pH to rise above 7.45

any metal cation and nonmetal anion held together by ionic bonds

salt (ionic compound) dissolve in water, resulting cations and anion in solution are electrolytes

only contain hydrogen and carbon and can exist in a chain or a ring

carbon-hydrogen backbone forms basis for all organic compounds

single subunits that can combine to build larger structures

many monomers linked together

2 monomers link by covalent bond to form polymers (anabolic reaction)

products are polymer compound and molecule of water

molecule of water added to polymer, atoms in water molecule split, covalent bond between monomers are broken

monosaccharide

made of carbon hydrogen and oxygen

polar and hydrophilic

main role if fuel via catabolic and redox reactions freeing chemical energy stored in carbs, which is then used to drive synthesis of nucleotide adenosine triphosphate

same molecular formula but dif structure

contain carbon, hydrogen and oxygen

non polar and hydrophobic

fatty acid

hydrocarbon chain bonded to carboxylic acid

no double bond between carbons, carbons become saturated with hydrogen ions

solid at room temp

one double bond between carbons which causes chain to bend

liquid at room temp

two or more double bonds between carbon

liquid at room temp

fatty acids do not package into long chains, they are stored by linking 3 fatty acids via dehydration synthesis to a modified 3-carbon sugar called glycerol

produces triglyceride which are stored in fat cells

similar to triglyceride

in place of third fatty acid we find a phosphate group (4 O and 1 P atom)

head is polar and hydrophilic, tail is nonpolar and hydrophobic

class of lipids

4-ring hydrocarbon structure

cholesterol forms basis for other steroids

enzymes

structural roles

body's defense

cell-cell communication

muscle contraction

oxidized as fuel

amino acid

each type of protein made up of combo of 21 dif amino acids

made of carbon, hydrogen, oxygen and nitrogen

R group makes it unique

amino acids linked by dehydration synthesis

two amino acids joined by polar covalent bond

long protein strand composed on nonpolar amino acids

polypeptide chain assembled` into "globe" and are polar

primary- amino acid sequence of its polypeptide

secondary- folds of polypeptide structure stabilized by H bonds between amino acids (alpha helix or beta pleated sheet)

tertiary- final 3-D shape assumed, stabilized by H bonds, covalent bonds. Interactions between R groups. ( nearly the same to secondary )

quaternary- manner in which polypeptide chains assemble (each chain has its own 1-3 structure tho)

process that destroys proteins shape

• heat

• pH changes

• chemicals

nucleotides

nucleic acids (genetic code polymers) are not oxidized into fuel but nucleotides play a key role in energy systems (Nucleotide adenosine triphosphate)

nitrogenous base

5-carbon (pentose) sugar

phosphate group

synthesized by adding 3rd phosphate to ADP

• highly endergonic due to neg charge in phosphate groups

nucleic acid

linked by dehydration synthesis