Ch 1 Biochemistry Flashcards
Isotope
atom of one element that have same chemical formula, but different number of neutrons. some are radioactive, known as radioisotopes
tracer
radioactive carbon can be used as a tracer, incorporated into molecules of carbon dioxide to track metabolic pathways
ionic bonds
form when electrons are transferred between anion and cation. Anions gain electrons, cations lose.
covalent bonds
form when atoms share electrons. results in a molecule
polar bonds
covalent bond with unbalanced forces. have stronger attractions.have negative and positive ends.
nonpolar bonds
covalent bonds with balanced forces. these attractions are weaker, like CO2. They are linear.
hydrophobic
repelled by water. lipids
hydrophilic
attracted to water. phosphate
characteristics of water
high specific heat, high heat of vaporization, adhesion properties, universal solvent, cohesion tension, and ice floats on water.
bicarbonate ion
most important buffer in human blood
buffer
substances that resist changes in pH. they absorb excess hydrogen ions ir donate hydrogen ions when too few.
Carbohydrates
made of carbon, hydrogen, and oxygen. supply quick energy, one gram releases 4 calories of heat when burned. made of monosaccharides, disaccharides, and polysaccharides.
monosaccharides
C6H12O6, glucose, galactose, and fructose. they are all isomers of each other.
disaccharides
two monos joined together by dehydration synthesis.
glucose + glucose =
maltose + water
glucose + galactose =
lactose + water
glucose + froctose =
sucrose + water
hydrolysis
opposite of dehydration synthesis; breakdown of compound with addition of water. occurs during digestion.
polysaccharides
polymers of carbs. formed by many monos with dehydration synthesis
4 types of polysaccharides
cellulose, starch, chitin, and glycogen
cellulose
polysaccharide that makes up cell walls
chitin
polysaccharide that makes up exoskeleton of arthropods and cell walls in mushrooms
starch
polysaccharide that plants store as energy
glycogen
polysaccharide that is stored in lover and skeletal muscle in humans.
lipids
fats, oils, and waxes. mostly consist of one glycerol and three fatty acids.
structure of glycerol
H | OH - C - H | OH - C - H | OH - C - H | H
fatty acids
hydrocarbon chain with carboxyl group at one end. exist as saturated or unsaturated.
saturated fats
come from animals. solid at room temperature. linked to heart disease. only single bonds between carbons.
unsaturated fats
extracted from plants, liquid at room temperature. have at least one double bonds between carbons and thus fewer hydrogens.
lipid functions
energy storage, membrane structure, and hormones
proteins
polymers of amino acids joined by peptide bonds. consist of carboxyl, amine group, and R attached to central carbon. R differs with each amino acid.
responsible for growth/repair.
primary structure of proteins
results from sequence if amino acids that make up protein chain
secondary structure of proteins
results from hydrogen bonding within molecules; creates helical nature of some proteins
tertiary structure of proteins
3D shape of protein, intricate, MOST DIRECTLY DETERMINES THE WAY IT FUNCTIONS AND ITS SPECIFICITY.
denature
enzymes denature at high temperatures, or have their tertiary structures altered beyond repair. protein cant function when denatured.
quaternary structure of proteins
consist of multiple polypeptide chains. hemoglobin has 4 chains.
substrate
chemical that an enzyme works on
induced fit model
describes how enzymes work when substrate enters the active site, it induces enzyme to shape shape slightly so substrate fits better.
cofactors
minerals that assist enzymes
coenzymes
vitamins that assist enzymes
prions
infectious proteins that cause brain diseases. mad cow disease. its a misfolded version of protein found in brains of mammals
nucleic acids
DNA and RNA, they carry hereditary information. polymers of nucleotides.
nucleotides
consist of a phosphate, 5 carbon sugar, and nitrogenous base.
what bases are purines
a and g
what bases are pyrimidines
c t u