3 primary elements that make up all living things
O, C, and H
atoms are made of…
protons (+)
electrons (-)
neutrons
ionic bonding
physical exchange of an electron from one atom to another
results in the production of a cation and anion
covalent bonds
the sharing of electrons
different types: single, double, triple
The most electronegative atom in a compound will draw the…
electron density
electrons equally shared?
non-polar covalent bond
electrons not equally shared?
polar covalent bond
hydrogen bonding
weak bond that occurs between a hydrogen atom attached to a very electronegative atom (usually O or N) and another molecule
hydrogen bonding is involved in…
protein folding
holding DNA strands together
dispersing heat (evaporative sweat)
and much more!
importance of water in the human body
cohesion: tendency of water molecules to cling together
adhesion: tendency of water molecules to cling to other molecules
thermal stability: high heat capacity; takes a lot of energy to raise the temp. of water
solvency: water is a powerful solvent
hydrophilic
tending to dissolve in water
hydrophobic
tending to fail to mix with water
acids
release H+ ions - “proton donor”
bases
release OH- ions - “proton acceptor”
organic compounds
carbohydrates
lipids
proteins
nucleic acids
carbohydrates
sugars & starches
classified according to size, function according to shape
lipids
insoluble in water
fatty acids, triglycerides, phospholipids, steroids
triglycerides
glycerol + 3 fatty acids
saturated fats
no double bonds - “straight”
dense fats - tend to clog up arteries & blood vessels
unsaturated fats
at least 1 double bond - “bent”
less dense
phospholipids
glycerol (sugar) with 2 fatty acid chains and a phosphate group attached
proteins
function determined by shape
most versatile molecule
made of amino acids
many functions of proteins
structural
communication
transport
enzymatic
recognition & protection
movement
cellular adhesion
primary structure of proteins
sequence of amino acids joined by peptide bonds
secondary structure of proteins
Alpha helix or beta sheet formed by hydrogen bonding
tertiary structure of proteins
folding and coiling due to interactions among R groups and between R groups and surrounding water
quaternary structure of proteins
association of 2 or more polypeptide chains with each other
denaturation
drastic conformational changes to a protein’s shape
enzymes
speeds up reactions
substrate-specific
nucleic acids
made of nucleotides (DNA & RNA)
contain ‘genetic code’
all living cells have…
plasma (cell) membrane
cytoplasm
intercellular fluid (ICF)
cytosol inside the cell
extracellular fluid (ECF)
fluid surrounding the cell
traits of the cell membrane
semipermeable
acts as a boundary
interactions with other cells often occur at the plasma membrane
structure of the cell membrane
aka: ‘phospholipid bilayer’ (2 layers = cholesterol + glycolipids + proteins make up the rest)
surface is hydrophilic
inside is hydrophobic
membrane proteins are classified as either…
integral proteins - embedded in the membrane
peripheral proteins - adhere to inside or outside of membrane
cilia
short projections
move objects through the body
flagella
only found in sperm
pseudopods
phagocytosis of bacteria
most important organelles to know for A&P…
membranous organelles
nucleus
mitochondria
lysosomes
rough & smooth endoplasmic reticulum
Golgi complex
ribosomes
types of cells
squamous
cuboidal
columnar
polygonal
stellate
spheroidal
discoidal
fusiform
fibrous
passive (no ATP required) processes
diffusion
osmosis
carrier mediated transport (e.g. facilitated diffusion)
process of facilitated diffusion
solute particle enters channel of a membrane protein
solute binds to a receptor on the carrier
carrier changes conformation
carrier releases solute on the other side of the membrane
active (ATP required) transport
primary active transport
vesicular transport
carrier method transport (e.g. ion pumps)
diffusion
movement of particles from areas of higher concentration to areas of lower concentration
osmosis
diffusion of water down its concentration gradient
tonicity
the ability of the solution to influence fluid concentration of the cell
hypotonic
water moves into the cell
hypertonic
water moves out of the cell
isotonic
no net change in water concentration
carrier-mediated transport
movement across a membrane using a protein
3 kinds of carrier-mediated transport
uniports - 1 molecule
symports - multiple molecules, same direction (aka: cotransport)
antiports - multiple molecules, opposite directions (aka: countertransport)
function of a receptor (as a membrane protein)
binds to chemical messengers such as hormones sent by other cells
function of an enzyme (as a membrane protein)
breaks down a chemical messenger and terminates its effect
function of a channel protein
constantly open and allows solutes to pass into and out of the cell
function of a gated channel
opens and closes to allow solutes through only at certain times
function of a cell-identity marker
distinguishes the body’s own cells from foreign cells
function of a cell-adhesion molecule (CAM)
binds one cell to another
primary active transport
uses ATP to push molecules up/against their concentration gradient
the sodium-potassium pump
vesicular transport
moves larger particles, droplets of fluid, and numerous molecules through the membrane by creating a plasma membrane pouch that pinches off and produces a vesicle
endocytosis (aka: phagocytosis)
exocytosis
endocytosis
move materials into cell
exocytosis
move materials out of cell
gene
a portion of DNA that encodes for an RNA molecule used to make a protein
order of nucleotides in a gene determines the order of amino acids in a…
protein
central dogma of molecular biology
DNA → mRNA → protein
after production, proteins can either be used the cell or transported out of it. either way…
proteins will undergo conformational folding aided by chaperone proteins
if protein is to be packaged or secreted, then…
post-translation modifications occur in the ER
carbohydrates are added in the Golgi complex
the regulation of genes implies that…
genes aren’t always turned on
mitosis
the process during which cells reproduce
the cell cycle consists of 2 main processes:
interphase
M (mitotic) phase
the 3 subprocesses that make-up interphase:
G1 phase: growth & normal metabolic roles
S phase: DNA replication
G2 phase: growth & preparation for mitosis
the 5 subprocesses that make-up M (mitotic) phase:
prophase
metaphase
anaphase
telophase
cytokinesis (division of the cell’s cytoplasm)