bio 112 - chapter 2

what is chemistry in physiology?

composition and characteristics of chemicals

what is matter?

anything that has mass and takes up space

what are elements?

simplest chemical substances; humans require ~20, mainly O, C, H, N

what is an atom?

smallest unit of an element; contains protons, neutrons, electrons

what is atomic number?

number of protons in an atom

what is mass number?

protons + neutrons

what are isotopes?

same element, different neutrons → different mass numbers; some are radioactive

what is an ion?

atom that gained or lost electrons → charged

what are the electron shell capacities?

1st shell: 2 electrons; 2nd & 3rd: 8 electrons

what is an ionic bond?

transfer of electrons; attraction between opposite charges (Na + CI-)

what is a covalent bond?

sharing of electrons; can be single, double, or triple

what is a polar molecule?

unequal sharing of electrons → slight charge differences

what is a hydrogen bond?

weak attraction between polar molecules (water)

difference between molecule and compound?

atoms bonded; atoms of different elements bonded (H2O)

What is a synthesis reaction?

builds larger molecules; used in growth and repair

what is a decomposition reaction?

breaks larger molecules into smaller ones

what is an exchange reaction?

parts of molecules switch places

what is a reversible reaction?

products can revert to reactants

what are enzymes?

biological catalysts that speed reactions without being consumed

what are acids?

electrolytes that release hydrogen ions (H+)

what are bases?

electrolytes that bind hydrogen ions

what does pH measure?

concentration of hydrogen ions

what is neutral pH?

pH 7 → equal H+ and OH-

what is acidic pH?

pH < 7 → more H+

what is basic pH?

pH 7 > → more OH-

what are buffers?

chemicals that resist pH changes

what are organic compounds?

contain C & H; include carbs, lipids, proteins, nucleic acids

what are inorganic compounds?

functions of water?

solvent, transport, temperature regulation, medium for reactions

functions of oxygen?

required for energy releases from nutrients

functions of CO2?

waste product; forms carbonic acid

functions of salts

provide ions for nerve impulses, muscle contraction, membrane transport

types of carbohydrates?

mono-, di-, polysaccharides

functions of carbohydrates?

energy source, structural materials

types of lipids?

triglycerides, phospholipids, steroids

functions of lipids?

energy storage, membranes, hormones

what are proteins made of?

amino acids containing C, H, O, N (sometimes S)

protein functions?

structure, enzymes, hormones, antibodies, energy

levels of protein structure

primary, secondary, tertiary, quaternary

what is denaturation?

loss of protein shape/function due to heat, pH, chemicals

what are nucleic?

DNA & RNA; store genetic info; direct protein synthesis

what is ATP?

modified RNA nucleotide; main energy carrier

what are inorganic compounds?

don’t contain C & H, include carbs, lipids, proteins, nucleic acids