Biology: The Chemical Basis of Life Flashcards
subatomic particles
protons, neutrons, electrons
nucleus
contains protons and neutrons
orbitals also called shells
surround nucleus and contain electrons
atomic number
number of protons; each element always has the same number
atomic mass
number of protons added with the number of neutrons
usually number of neutrons equals number of protons but can vary
isotopes
same element with different number of neutrons so baby different atomic mass
matter
anything that occupy space and has mass; composed of atoms
solid
atoms closely linked
liquid
atoms move more freely
gas
atoms move rapidly
mass
quantity of matter in object happens
elements
composed of only one type of atom
pure substance that can’t be changed into simpler substance
atom
smallest unit of an element maintaining chemical properties
molecule
assembly of two or more atoms
compound
assembly of two or more different atoms
electronegativity
ability of the atom to attract electrons- increases as go to the right of the periodic table
how are atoms held together
ionic bonds, covalent bonds, hydrogen bonds, Van der waal force
Ionic bonds
involves gain and loss of electric
occurs with big difference in electronegativity
cation
if electron is lost in Ionic bonds
anion
if electron is gained
covalent bonds
involves sharing of electrons
occurs when small differences in electronegativity of atoms
polar covalent bond
unequal sharing of electrons
leads to a partially positive atom and partially negative
nonpolar covalent bond
equals sharing of electrons
hydrogen bonds
partially positive hydrogen atom attracted to parsing negative Adam and different molecules
easy to make and break
Van der Waal Forces
slight attraction that happens between oppositely charged regions of nearby molecules
why does the electronic and the water stay closer to oxygen
oxygen is more electronegative
so oxygen and is slightly negative and hydrogen and is slightly positive
five special properties of water
powerful solvent cohesion adhesion resists change in temperature ice floats
hydrophilic
water loving dissolve in water because they’re polar
hydrophobic
water fearing because there non-polar
cohesion
attraction between like substances
creates high surface tension
adhesion
attraction of unlike substances
capillary action-adhesion pulls water up a narrow tube against gravity
water resists changes in temperature
has a high heat capacity
absorbs and releases large amounts of heat with only a slight temperature change
ice floats
water expands and becomes less dense as it freezes
hydrogen bonds form crystals expanding the water and decreasing its density
mixture
when substances are evenly spread out
solute
dissolves in solvent
solvent
what the solvent is dissolved into
concentration
amount of solute dissolved in solution
saturated solution
no more solid can be dissolved
aqueous solution
water is the solvent
pH
measures amount of H+ in an obvious solution
H2O= H+ and OH-
scale from 0-14
acids
donates H+ to
high H+ concentration
pH of 0-6
base
accepts H+ from solutions
pH of 8-14
more OH- than H+ in solution
neutral
neither add or remove H+ from solution
pH= 7
why is pH so important organisms
changing pH can change the shape of molecules making them useless
buffers
maintain constant pH when either acids or bases are added to them
reactants
starting material
product
ending material
why the chemical reactions occur in cells
matter tends to go towards unorganized state (entropy)
living things need energy to maintain the chemical and physical order
redox reactions
allow energy to pass from molecule to molecule
lose electrons= oxidized
gain electrons= reduced
Activation energy
energy needed to start a reaction
catalyst
substance that reduces the amount of activation energy needed
what is an organic molecule
must contain carbon
all living things made of chains of carbon atoms
carpet is unique because the bonds of many elements at once
monomer
small simple molecules
polymers
monomer linked together many times
macromolecule
molecules with hundreds or thousands of monomers
dehydration reactions
joining a monomer to a polymer by removing the water molecule
hydrolysis reaction
breaking down a polymer by adding a water molecule
hydroxyl
OH
alcohol, sugars
polar, hydrophilic
carboxyl
COOH
amino acids, fatty acids, sugars
polar, hydrophilic, weak acid
amino
NH2
amino acids
polar, hydrophilic, weak base
phosphate
PO3
DNA, ATP, phospholipids
polar, hydrophilic, acid
Carbony
C=O
acetone, sugar
polar, hydrophilic
methyl
CH3
fatty acids, oils, waxes
nonpolar, hydrophobic
what molecules of life do cells build
carbohydrates, proteins, lipids, and nucleic acids
how do you make sugars?
1 carbon: 2 hydrogen: 1 oxygen
sugars always and in “ose”
monosaccharides or simple sugars
C6H 12 O6
positions of atoms determine chemistry
isomer
same molecular formula but different structures and properties
disacchride
two monosaccharides joined by dehydration reaction
polysaccharides
do you hundred to a few thousand monosaccharides joined together
where are sugars made in animals
not made ingested and stored as fat
where are sugars made in plant cells
chloroplasts makes sugar
how do you make a protein
start with an amino acid
linked amino acids to be, proteins covalently bonded by peptide bonds a dehydration reaction
two amino acids is it a dipeptide
three a more amino acids is a polypeptide
what is an amino acid made out of
Ameena, carboxyl, hydrogen, carbon and 20 different amino acids due to different side chains
how do you make a protein continued- structures
primary structure- unique sequence of amino acids
secondary structure- coils are folding proteins
tertiary structure- overall three-dimensional shape
quaternary structure- combination of two or more proteins
what happens to proteins if the temperature or pH changes
it becomes denatured and does not work
what to proteins do
make structures storage for growing offspring fighting disease enzymes- biological catalysts transport
enzyme
protein that controls the rate of chemical reactions
and in “ase”
only fits specific reactants
just like a catalyst
where are proteinss made
in animal and plant cells assembled in ribosomes
what structures to lipids make
oils, fats, the waxes
mainly nonpolar groups
fatty acids
not a polymer
energy storage insulation and protection
one and a long carbon chain-hydrophobic
other end carboxyl group-hydrophilic
saturated fatty acids
no double bonds
unsaturated fatty acids
at least one double bond
cholesterol
not a polymer
at least for linked carbon rings
make steroids and part of cell memberane
phospholipid
hydrophobic fatty acid tale with phosphate hydrophilic head
cell membrane is two layers of phospholipids lined up tail to tail
where lipids made
in smooth endoplasmic reticulum
what does an nucleic acid do?
storage and transport of important information about a cell
how do you make nucleic acid?
start with nucleotides
link nucleotides with covalent bondsthrough dehydration reaction to create nucleic acid polymer of nucleotides
what are nucleotides made of
phosphate sugar and nitrogenous base
two types of nucleic acid
deoxyribonucleic acid determined characteristics and direct cell activities
ribonucleic acid stores and transfers information from DNA to make proteins
where are nucleic acids made
in animal and plant cellsin the nucleus
