Chapter II : Atoms, Ions and Molecules Flashcards
What are the three forms of matter?
- solid, liquid, gas
Matter is composed of what?
- atoms, which are the smallest particle that exhibits the chemical properties of an element
What are the three ways elements are called based on the percentage by weight in the body?
- major, lesser, or trace
What are the six elements that make up a 98% of weight on the body?
- O, C, H, N, Ca, P
What are the 6 elements that make up less than 1% of the total body weight?
- S, K, Na, Cl, Mg, Fe
What the mass of protons, neutrons and electrons?
- protons = 1 amu
- Neutrons - 1 amu
- Electrons= 1/1800th
Whats the average atomic mass made up of?
- protons and neutrons
What are isotopes?
- are different atoms of the same element, have the same number of protons and electrons but different number of neutrons
What’s the most prevalent carbon isotope?
- carbon 12 (with 6 neutrons)
Why are radioisotopes unstable?
- becuase they contain excess neutrons
How do radioisotopes lose nuclear components?
- in forms of high energy radiation
What is the physical half-life?
the time for 50% of radioisotopes to become stable, can vary from seconds to thousands of years
What’s the biological half-life?
the time required for half of the radioactive material from a test to be eliminated from the body
What’s the relationship of the octect rule and chemical stability?
a complete outer shell with eight electrons increases chemical stability
What are ions?
groups of atoms with a positive or negative charge
How are ions made?
- by the loss or gain of electrons
What are cations?
positive ions, made by the loss of electrons
What are anions, and how are they made?
negative ions, made by the gain of electrons
What are polyatomic ions?
anions, composed of more than one atom
Elements in the first, second, or third columns are usually anions or cations?
cations
Which side of the periodic table is metallic?
left side
What type of bonds do cations and anions form?
ionic bonds
Sharing of bonds are called?
covalent bonds
What are isomers?
molecules with the same number and kind of elements arranged differently in space
Glucose, Galactose and fructose differ in what? and therefor are called?
structure, called isomers
What are the four elements that combine in covalent bonds most commonly?
O, N, C, H
What’s the simplest covalent bond?
- between two hydrogen atoms
How do you determine how many covalent bonds an element with form?
depending on how many electrons the element needs to satisfy the octect rule…
- for example: Oxygen needs two electrons to have 8, therefore forms 2 covalent bonds
How is Oxygen with electronegativity?
- very electronegative
How can Carbon bond? shape wise….
in branches, rings, and branched chains
How is it determined whether a bond is polar or nonpolar?
based on their electronegativity
Nonpolar means…
equal sharing
“no problem”
Polar means…
not equal sharing
Referring to the periodic table how is electronegativity ?
increases left to right, decreases top to bottom
The bond between Carbon and Hydrogen is considered what type of bond?
nonpolar
If a covalent bond is more electronegative how will a bond form?
- it will be partially negative, partially positive
The bond between C-H?
nonpolar
The bond between O-H?
polar
Amphipathic molecules are what?
partially polar, partially nonpolar molecules
Mole value:
6.022x10^23
Moles is moles per what?
liters
Mole definition
of molecules
Whats the difference between organic and inorganic molecules?
organic contains C-H bonding, inorganic does not
What type of bond is CO2? (organic or inorganic?
an organic compound
What do hydrocarbons contain?
carbon, hydrogen
Hydrocarbons are nonpolar which means they are?
hydrophobic
Intermolecular attractions are:
weak chemically attractions between molecules
Why are intermolecular molecules important?
bc they maintain shape of complex molecules (i.e. DNA and protein)
The intermolecular Hydrogen bond forms between what?
between polar molecules, partially positive hydrogen atom, partially negative Oxygen atom
Hydrogen bonds are weak or strong?
individually weak, collectively strong
Water composes what fraction of the human body?
2/3 by weight
Why is water liquid at room temperature ?
because of the hydrogen bonding
Functions of liquid water?
- transports, lubricates, cushions and excretes waste
Temperature def:
the measure of kinetic energy of atoms or molecules within a substance
Specific heat def:
the amount of energy require to increase the temperature of 1 gram of a substance by 1 degree Celsius
Heat of vaporization def:
the heat required for the release of molecules from a liquid phase into a gaseous phase for 1 gram of a substance
Water is the solute or solvent of the body?
solvent
Why is water called the universal solvent?
because most substances dissolve in it
___________ portions of amphipathic molecules dissolves easily in water
polar
How is a phospholipid bilayer made?
nonpolar tails of phospholipids grooup together while polar heads have contact with water
Water spontanously dissocitates to form ____?
ions
An acid dissociates in water to produce what two things?
- hydrogen ion and an anion
An acid is also called a what?
proton donor
A base accepts what when added to a solution?
a hydrogen ion
A base is also called what?
proton acceptor
pH is a measure of what?
hydrogen ions
Moving from one increment to another with the pH value is called a what?
a tenfold change
(ex: a pH of 6 has 10 times greater concentration of H+ than pure water
Solutions with equal concentrations of H+ and OH- are called what? Higher H+? Higher OH-?
base, acid,base
Urine can range a pH from ?
pH 4-8
If a person is acidosis what will happen to the urine?
more acidic
If a person is overhydrated the urine will be a pH of?
pH 7-8
A buffer does what?
maintains the pH changes
Concentration is determined by what?
the amount of solute dissolved in a solution
Concentrations are expressed how?
- mass/volume
- mass/volume percent
Molarity is?
moles/liter solution
Molality is?
moles/kg solute
Which changes with temperature molarity or molality?
Molarity. Molality doesn’t change with temperature because liquid expands and contracts
Polymers are also called?
macromolecules
Monomers are also called?
micromolecules
Dehydration is?
taking water out, putting bonds back together
Hydration is?
putting water back in, breaking bonds
Which macromolecule is not a polymer?
lipid
What does lipids function as?
stores nutrients, cellular membrant components and hormones
Lipids occur in 4 primary classes, what are they?
triglycerides, phospholipids, steroids, eiconsanoids
Are lipids hydrophilic or hydrophobic?
Hydrophobic
Lipids: tryglycerides do what?
store energy
Tryglcerides are formed during what type of synthesis?
dehydration
Tryglycerides help the body in what ways?
- long term energy storage in adipose tissue, structural support, cushioning, and insulation
What is the structural form of tryglycerides?
glycerol molecule and 3 fatty acids
What’s the difference between saturated, unsaturated, and polyunsaturated fatty acids?
- saturated: no double bonds
- unsaturated: one double bond
- polyunsaturated: two or more double bonds
Adipose tissue forms triglycerides when what happens?
- when energy is excess…termed lipogenesis
Adipose tissue breaks down triglycerides when what happens?
- when energy is needed
- termed lipolysis
Phospholipids are what?
- membranes
What makes up phospholipids membranes?
- a hydrophobic tail and a hydrophilic head
(Lipids) steroids are what?
ringed structures including some hormones
Most animal fats are (saturated or unsaturated)? how about plant fats?
- animal is saturated
- plats are unsaturated
Partial hydrogenation can lead to what?
trans fats
Trans fats can increase the risk of what two health conditions?
- heart attack and stroke
Hydrogenation
high pressure is H+
- preservation of food
What is the structure of Glucose?
a six carbon carbohydrate
What’s the most common monosaccharide?
glucose
Glucose is the primary ________
nutrient supplying energy to cells
During glycogenesis what happens?
glucose bonds to polysaccharide glycogen
Glycogenolysis is?
the broken down form glycogen
(T/F) Every life form on the planet can use glucose as energy?
true
What are nucleic acids?
macromolecules that store and transfer genetic informatio in cells
Two classes of nucleic acids?
DNA and RNA
Nucleotide monomers are bonded by what?
phosphodiester bonds
What makes up the nucleotide?
sugar, phosphate group and nitrogenous base
- sugar phosphate backbone
Pyrimidines =
cytosine, uracil, thymine
Purines=
adenine, guanine
Where is DNA found?
mitochondria and nucleus
The double strand in DNA is held together by ?
hydrogen bonds
RNA is found where?
nucleus and within cytoplasm of the cells
What does RNA not contain, and what is it replaced with?
Thymine, replaced with Uracil
What does ATP stand for?
adenosine triphosphate
What is ATP
nucleotide compose of nitrogenous bases, adenine, ribose sugar and three phosphate groups
Where are the covalent bonds at in ATP?
between the two phosphate groups, it releases energy when broken
ATP is the central molecule in what?
chemical energy transfer within cells
NAD+ stands for
nicotinamide adenine dinucleotide
FAD stands for
flavin adenine dinucleotide
What does NAD + and FAD do?
participates in the formation of ATP
Proteins serve as what? (7 things)
- serve as catalysts (enzymes)in metabolic reactions
- act in defense
- aid in transport
- contribute to structural support
- cause movement
- perform regulation
- provide storage
Monomers of proteins?
amino acids
How many amino acids are total in living organisms?
20
Amino acid structure?
carboxylic acid + amine
How are amino acids bonded?
peptide bonds
How are the peptide bonds formed?
during dehydration synthesis reaction
Where is the peptide bond formed?
between the amine group of one amino acid and the carboxylic group
What’s the N-terminal group of amino acids?
free amine group
What’s the C-terminal group of amino acids?
free carboxyl group
Amino acids are organized based on what groups?
the R groups
Nonpolar amino acids contain what
contain R groups with hydrogen and hydrocarbons
Polar amino acids contain what
R groups with other elements
Primary structure:
linear sequence of amino acids
Conformation:
three- dimensional shape of protein
The secondary structures what? what two things does it look like?
structural patterns frm hydrogen bonding
- beta pleated sheets
- alpha helix
Tertiary structure: (two things visual)
final three dimensional shape of polypeptide chain
- globular proteins
- fibrous proteins
Quantenary structure
present in proteins with two or more polypeptide chains
Denaturing is what?
shape change to a protein
Other than heating what else can cause denaturing?
pH changes
