PHYSIOLOGY 1021 LECTUES 1 & 2 QUESTIONS
Homeostasis - (ANSWER)the ability of the body to maintain a relatively constant internal
environment
How is homeostasis maintained? - (ANSWER)negative feedback loops, either long-distance
control or local control
Intraceullular Fluid (ICF) - (ANSWER)Fluid found inside the cells (cytoplasm) - 2/3 of total
body water is found here
Extraceullar fluid (ECF) - (ANSWER)fluid outside the cell - interstitial fluid and plasma
interstitial fluid - (ANSWER)fluid in the spaces between cells
Plasma - (ANSWER)Liquid part of blood
hydrophilic - (ANSWER)glycerol/phosphate heads
- loves water
- always faces fluid
Hydrophobic - (ANSWER)fatty acid tails
- water fearing
cation - (ANSWER)- positive charge
- sodium, potassium and calcium
anion - (ANSWER)- negative charge
- chloride
,PHYSIOLOGY 1021 LECTUES 1 & 2 QUESTIONS
salty banana - (ANSWER)sodium outside, potassium inside
Diffusion - (ANSWER)Movement of molecules from an area of higher concentration to an
area of lower concentration until equilibrium
active transport - (ANSWER)Energy-requiring process that moves material across a cell
membrane against a concentration difference
- very selective
- can be competitively inhibited
- will saturate
simple diffusion - (ANSWER)- movement of a solute from an area of high concentration to
an area of low concentration
- hydrophobic will cross by simple diffusion - fatty acid tails are a barrier to hydrophilic
substances
3 ways to cross the membrane:
1. between phospholipids
2. using transmembrane protein
3. using a "pocket" of membrane
factors affecting simple diffusion - (ANSWER)- lipid solubility - has to be hydrophobic
- surface area - the bigger the target the faster the rate of diffusion
- size - small = faster
- thickness - thick will slow down the rate of diffusion
- concentration gradient - the buffer the concentration gradient the faster it goes
, PHYSIOLOGY 1021 LECTUES 1 & 2 QUESTIONS
Fick's Law - (ANSWER)rate = surface area x concentration gradient/membrane thickness
- substances like oxygen, carbon dioxide, and alcohol
- hydrophobic, small substances
transmembrane proteins - (ANSWER)Transmembrane proteins are integral proteins that
do not extend all the way through the membrane.
- outside to inside
- membrane channel
- membrane carrier - binding site
- used by substances that are small and hydrophilic: ions, water
- very selective
- can be competitively inhibited
- will saturate
channel-mediated diffusion - (ANSWER)- fairly selective on size and share
- concentration gradient - bigger the better
- number of channels- more channels = faster
- size of molecule - smaller = better
- charge on molecule - na+ cation, sodium will go if channel is neg, opposites attract
facilitated diffusion - (ANSWER)- membrane carrier
- very selective
- can be competitively inhibited
- will saturate
- for large hydrophilic substances: glucose, amino acids
Homeostasis - (ANSWER)the ability of the body to maintain a relatively constant internal
environment
How is homeostasis maintained? - (ANSWER)negative feedback loops, either long-distance
control or local control
Intraceullular Fluid (ICF) - (ANSWER)Fluid found inside the cells (cytoplasm) - 2/3 of total
body water is found here
Extraceullar fluid (ECF) - (ANSWER)fluid outside the cell - interstitial fluid and plasma
interstitial fluid - (ANSWER)fluid in the spaces between cells
Plasma - (ANSWER)Liquid part of blood
hydrophilic - (ANSWER)glycerol/phosphate heads
- loves water
- always faces fluid
Hydrophobic - (ANSWER)fatty acid tails
- water fearing
cation - (ANSWER)- positive charge
- sodium, potassium and calcium
anion - (ANSWER)- negative charge
- chloride
,PHYSIOLOGY 1021 LECTUES 1 & 2 QUESTIONS
salty banana - (ANSWER)sodium outside, potassium inside
Diffusion - (ANSWER)Movement of molecules from an area of higher concentration to an
area of lower concentration until equilibrium
active transport - (ANSWER)Energy-requiring process that moves material across a cell
membrane against a concentration difference
- very selective
- can be competitively inhibited
- will saturate
simple diffusion - (ANSWER)- movement of a solute from an area of high concentration to
an area of low concentration
- hydrophobic will cross by simple diffusion - fatty acid tails are a barrier to hydrophilic
substances
3 ways to cross the membrane:
1. between phospholipids
2. using transmembrane protein
3. using a "pocket" of membrane
factors affecting simple diffusion - (ANSWER)- lipid solubility - has to be hydrophobic
- surface area - the bigger the target the faster the rate of diffusion
- size - small = faster
- thickness - thick will slow down the rate of diffusion
- concentration gradient - the buffer the concentration gradient the faster it goes
, PHYSIOLOGY 1021 LECTUES 1 & 2 QUESTIONS
Fick's Law - (ANSWER)rate = surface area x concentration gradient/membrane thickness
- substances like oxygen, carbon dioxide, and alcohol
- hydrophobic, small substances
transmembrane proteins - (ANSWER)Transmembrane proteins are integral proteins that
do not extend all the way through the membrane.
- outside to inside
- membrane channel
- membrane carrier - binding site
- used by substances that are small and hydrophilic: ions, water
- very selective
- can be competitively inhibited
- will saturate
channel-mediated diffusion - (ANSWER)- fairly selective on size and share
- concentration gradient - bigger the better
- number of channels- more channels = faster
- size of molecule - smaller = better
- charge on molecule - na+ cation, sodium will go if channel is neg, opposites attract
facilitated diffusion - (ANSWER)- membrane carrier
- very selective
- can be competitively inhibited
- will saturate
- for large hydrophilic substances: glucose, amino acids
