Lecture Exam 1 Flashcards
physiology
the study of biological function of the human body (how the body works)
total body water ranges
45-75% of body weight
what is variation of total body water due to?
body fat
average body water for males
60%
what makes up total body fluid?
intracellular & extracellular fluid
what is intracellular fluid rich in?
K+ and proteins
what makes up extracellular fluid (ECF)?
blood and interstitial fluid
what is interstitial fluid?
fluid between the cells
what is intracellular fluid (ICF)?
fluid within cells
what is extracellular fluid (ECF)?
fluid outside cells
which compartment is the greatest proportion of total body water found?
intracellular fluid
define solute
particles dissolved in a solvent to form a solution
what unit is solute concentration measured in?
M (molarity)
define homeostasis
the ability of the body to maintain a constant internal environment despite changing conditions in the external environment
what is dynamic constancy characterized by?
constant change
what maintains dynamic constancy?
negative feedback loops
how does the sensor transfer information to the integrating center?
affarent nerve
what does the integration center do?
it processes the information and sends the message to the effector
how does the integrating center get information to the effector?
effarent nerve
what does the effector do?
carries out response/effect
define antagonistic
2 effectors act in opposite directions
define synergistic
2 effectors act in the same direction
net action is greater than just the sum of each individual action
define permissive
one effector increases the action of another
define additive
two effectors act in the same direction
net action is the sum of each individual action
define postive feedback
action of effector amplify the initial stimulus
body wants more stimulation
examples of positive feedback
childbirth and blood clotting
what are the 4 main biomolecules?
carbohydrates
lipids
proteins
nucleic acids
examples of disaccharides
sucrose, lactose, maltose
examples of polysaccharides
glycogen, starch
how are disaccharides formed?
dehydration synthesis of 2 monosaccharides
where is glycogen found?
liver and muscles
what are common features of lipids?
non-polar
insoluble in water (hydrophobic)
4 examples of lipids
triglycerides
phospholipids
steroids
eicosanoids
define triglycerides
3 fatty acids bound to glycerol
what is needed to make steroids?
cholesterol
what are eicosanoids?
prostaglandins and leukotrienes
broken down phospholipids
what complex molecule serves the wides variety of functions?
proteins
what are the 4 functions of proteins?
transport
contraction
immunity
regulation
what is building block of proteins?
amino acids
what links 2 amino acids?
peptide bonds
what are secondary protein structures
alpha helix and beta pleated sheets
hydrogen bonds
describe tertiary protein structure
three-dimensional folding pattern of a protein due to side chain interactions
describe quaternary protein structure
several polypeptide chains bound together
define nucleotides
5 carbon sugar, phosphate group, nitrogenous base
what are the functions of cell membrane proteins?
transport molecules
enzymatic regulation
receptors for signaling molecules
cell markers
function of nucleus
stores cell info
function of nucleolus
produces ribosomes
function of ribosomes
makes proteins
function of mitochondria
produces ATP
function of golgi complex
modifies, packages, and transports material out of the cell
function of lysosomes
break down molecules through hydrolysis
function of peroxisomes
break down molecules through redox
define catabolic metabolism
breaking down; exergonic
define anabolic metabolism
synthesis; endergonic
define condensation
reverse of hydrolysis; endergonic
define hydrolysis
use of water to break down; exergonic
define phosphorylation
addition of a phosphate group
changes protein activity
define dephosphorylation
removal of a phosphate group
changes protein activity
what is the byproduct that oxidation-reduction reactions produce?
hydrogen peroxide
what is potential energy?
stored energy
what is kinetic energy?
energy of motion
what does specificity do?
limits the type of molecule the enzyme interacts with
what is induced fit?
the conformation of enzyme changes to fit substrate
what direct factors affect reaction rate?
substrate concentration
catalytic rate
affinity
what indirect factors affect reaction rate?
temp
pH
what is glycolysis?
breakdown of glucose to 2 pyruvate molecules
2 ATP, NADH gained
what does oxidative phosphorylation require?
oxygen
what is the main goal of glucose oxidation?
to produce ATP
what are the 3 types of passive transport?
simple diffusion
facilitated diffusion
osmosis
what are the 2 types of active transport?
primary and secondary
how does facilitated diffusion happen?
by carriers
what can freely pass through the membrane?
gas
what is the driving force of simple diffusion?
the solutes concentration gradient
pores are always ___?
open
channels are gated by what?
a door
which side of the cell is more negative?
the inside
how are ion channels named?
according to the substance that is allowed to pass through
when does membrane potential exist?
when there is both electrical and chemical force regardless of direction
if membrane potential (Vm) = equilibrium potential (Ex) what does net force equal?
0
looking at absolute number, if Vm is less than Ex, what direction will the electrochemical driving force be?
out of the cell
looking at absolute number, if Vm is more than Ex, what direction will the electrochemical driving force be?
into the cell
what determines rate of diffusion for ion transport?
electrochemical gradient
ion channel permeability
membrane surface area
what does Vmax mean?
all carriers have been used
what does it mean when 2 curves have the same Km?
they have the same affinity
where are GLUT4 molecules synthesized?
rough ER
what is primary active transport accomplished by?
protein pumps
describe secondary active transport
uses energy from movement of one substance to move another
energy is NOT ATP
what is osmosis driven by?
osmotic pressure
which way does water move?
from low osmotic pressure (low solute high water) to high osmotic pressure (high solute low water)
what are aquaporins?
channel proteins fro water
what cells are aquaporins always present?
RBCs
what is osmolarity equal to?
solute concentration
what direction does tonicity move?
low to high tonic solution
isotonic
cell does not change size
hypertonic
water moves out, cell shrinks
hypotonic
water moves in, cell swells
what are eicosanoid messengers derived from?
arachidonic acid
what is half-life?
time for a chemical to decrease its concentration by half
what is an agonist?
compounds that bind to receptor and cause normal response
what is an antagonist?
a blocker
what are adenylate cyclase (GPCR) 2nd messengers?
cAMP and protein kinase A
4 primary cell & tissue types
muscle
nervous
epithelial
connective
average body water for females
50%
K+ ICF
140 mM
K+ ECF
4 mM
Na+ ICF
15 mM
Na+ ECF
145 mM
where is Mg2+ concentration higher?
ECF
where is Ca2+ concentration higher?
ECF
where is Cl- concentration higher?
ECF
where is HCO3- concentration higher?
ECF
where is glucose concentration higher?
ECF
where is amino acid concentration higher?
ICF
where is ATP concentration higher?
ICF
where is protein concentration higher?
ICF
examples of monosaccharides
glucose, fructose, galactose
what is the primary purpose of triglycerides?
provide energy
what are phospholipids made of?
polar head and non polar tail
what is structure of steroids?
3 6-carbon rings joined to a 5-carbon ring
what is the primary function of steroids?
regulation
primary protein structure
amino acid sequence
what is activation energy?
energy difference between initial and transition state
what is the initial substrate of Krebs cycle
acetyl CoA
where does oxidative phosphorylation occur?
microchondria
what are the functions of the membrane
enclose cell contents
act as mechanical barrier
determine cell composition & function
how can simple diffusion happen?
directly through lipid bilayer, pores, or gated channels
what substrates can move through using simple diffusion?
uncharged & hydrophobic
what is flux?
rate of diffusion
what is the rate of diffusion dependent on?
permeability of membrane
magnitude of concentration gradient
surface area of membrane
what are the characteristics of a channel?
acts like a pore & is substance specific
what is the driving force of ion channels?
electrochemical gradient
what is ion channel selectivity determined by?
pore size
charges of amino acids
how does electrochemical driving force act when chemical & electrical forces are in the same direction?
acts in the direction of each force
magnitude is the sum of the two forces
how does the electrochemical driving force act when chemical & electrical forces are in opposite directions?
acts in the direction of the stronger force
magnitude is larger - smaller force
what is secondary active transport accomplished by?
symporters and antiporters
what does tonicity describe?
a property of a solution
what is tonicity determined by?
concentration of non-penetrating solutes
direct intracellular communication
cells are directly in contact, molecules pass directly
indirect intracellular communication
one cell secretes messenger, messenger binds to receptor on itself or another cell
what do gap junctions do?
provide cytoplasmic channels between adjacent cells, direct communication
where are gap junctions common?
smooth and cardiac muscle
paracrines
secrete messenger into ECF, binds to receptor on neighboring cell
autocrines
secrete messenger into ECF which binds to receptor on itself
neurotransmitter
secreted from neurons into synapse; bind to receptor on postsynaptic cell
hormones
secreted from endocrine cell into blood; bind to receptor on target cell
what are amine messengers derived from?
amino acids
catecholamines
dopamine, norepinephrine, epinephrine; derived from tyrosine
thyroid hormones
T3 and T4; derived from tyrosine
serotonin
derived from tryptophan
histamine
derived from histidine
what are steroid messengers derived from?
cholesterol
how are messengers transported?
diffusion or blood (hormones only)
which messengers have a sort half-life?
messengers dissolved in plasma
which messengers have a long half-life?
messengers bound to plasma protein
where do lipophobic (hydrophilic) ligands bind?
cell membrane
where do lipophilic (hydrophobic) ligands bind?
within the cell
what does the magnitude of target cell response depend on?
messenger concentration, number of receptors, affinity
fast response receptors
receptor and effector are the same protein
slow response receptors
receptor and effector are separate proteins coupled by G proteins
phospholipase C (GPCR) 2nd messengers
IP3 (activates Ca2+) & DAG (activates protein kinase C)