Bio Lab Exam 1

What does it mean to say that a plant cell is "isotonic" to its surrounding solution?

The cytosol has the same osmolarity as the surrounding fluids

osmosis refers specifically to the

diffusion of water molecules across a membrane

Da -

mass number (protons + neutrons)

osmosis

net movement of water through a selectively permeable membrane from an area of low osmolarity to one of higher osmolarity

isotonic

no net gain or loss of water because the osmolarity of the cell and its environment are equal

dialysis membrane

selectively permeable has holes that let water through but not larger molecules

action of enzyme depends on

shape of active site matching shape of substrate

line graph

show change of dependent variable over constant change in independent variable

pie chart

shows distribution of data that adds up to 100%

objective lens 4x 10x 40x 100x

total magnification 40x 100x 400x 1000x field diameter 4,500 1,800 450 180

enzyme

accelerates and steers chemical processes in organisms, protein who job is to facilitate a chemical reaction

bar graph

used for discrete independent variables

the active site of an enzyme is

catalytically active region of an enzyme fragile and dynamic complementary in shape and chemistry

hypertonic

external medium is more concentrated, water leaves the cell, shrinkage, plasmolysis 1q`

hypotonic

external medium is more dilute, water enters with its concentration gradient, cell will swell

lactose --> with use of lactase is broken down into

galactose + glucose

the osmotic pressure of a solution is proportional to

gas constant, temperature, concentration of the solution

what is the natural role of lactase in mammals?

hydrolysis of a dissacharide

lab 1

study 1: two drugs are tested for their effectiveness in slowing cell division study 2: measures the quantity of proteins known to be involved in cell growth after 24 hour exposure to cladribine or subiolsamide study 3: tests the toxicity of cladribine and subiolsamide on non-dividing, healthy cells

lab 3 will be detected by

colorimetric measurement using a spectrophotometer

scatter plot

determine correlations between two continuous variables

osmotic pressure

CRT c = total solute concentration in moles/liter r = gas constant 0.082 (l x atm) / (mol x k) T = kelvin (273 + Cº)

lactase catalyzes the conversion of

ONPG into galactose and ONP

lactase

enzyme that catalyzes the digestion of lactose

lab 2 - you will measure

the movement of water across dialysis tubing