BIOL1020 Lab 3: Osmolarity & Tonicity

Define osmosis

diffusion of water, low to high solute concentration

Define osmolarity

the total solute concentration of a solution, considers all solutes; penetrating & NP

What does it mean to be hypoosmotic

lower solute concentration in comparison to the amount of water

What does it mean to be hyperosmotic

higher solute concentration than the amount of water

What does it mean to be isoosmotic

equal amount of solutes as there is water

Define tonicity

concentration of non penetrating solutes, cell volume changes

What does it mean to be hypotonic

water moves inside because there’s less NP solutes

What is the result of being hypotonic

swelling

What does it mean to be hypertonic

water moves out because there more NP solutes that cannot cross the membrane

What is the effect of hypertonicity

shrinkage

What does it mean to be isootonic

equal number of NP solutes to the solution

Explain the absorbance levels with each temperature

cold: absorbance decreased

room temp: absobance increased

hot: absorbance increased

What temperature had the greatest effect on beet cell membranes

the hottest temperature

Describe how the plasma membrane works

selective & semipermeable

Define diffusion

passive movement of a solute from areas of high concentrations to low

What are the two types of diffusion

simple and facilitated

define simple diffusion

solutes moving across a membrane with no help & no energy required

Define facilitated diffusion

a solute moves across a membrane with the assistance of a transport protein

What are the factors that influence permeability of solutes

size, polarity, & charge

Which 2/3 factors that influence permeability are most influential

polarity & charge

How do enzymes catalyze chemical reactions

by lowering the activation energy

In what conditions do enzymes behave differently

pH & temp

What is a reaction rate

the amount of substrate that binds to an activate size > products

How would you calculate maximum reaction rate

finding the Vmax > (# of substrates/time)

What are the types of inhibitors

competitive and non-competitive

Explain competitive inhibitors

bind to the active site & compete with normal substrate

Explain non-competitive inhibitors

bind to the allosteric site > changes an enzymes shape so it can't bind to it

What happened to reaction rate when inhibitors were involved

decreases

Explain how inhibitor concentrations influence the number of substrates of an enzyme

the more inhibitors present, the less substrates have the opportunity to bind