Bio 108 Lab Kapros

What is the definition of a selectively permeable membrane?

a membrane that differentiates between different types of molecules and only allows some molecules to pass through

Why is diffusion important?

Diffusion allows cells to obtain the necessary substances they need to grow and survive

What is an example of diffusion?

allows the movement of oxygen, carbon dioxide, and other molecules across the cell membrane

What is the definition of tonicity?

the ability of a surrounding solution to cause a cell to gain or lose water

Why is osmosis important?

it is necessary for cells to maintain homeostasis

What is an example of osmosis?

cell membranes are semi-permeable, water can flow in and out freely, but other molecules cannot

What is the definition of Diffusion?

molecules move from an area of high concentration to an area of low concentration

What is the definition of Osmosis?

the diffusion of water through a selectively permeable membranes from a region with a low solute concentration to a high solute concentration

What is the definition of Solvent?

dissolving agent (does the dissolving)

What is the definition of solute?

dissolved substances (gets dissolved)

What is the definition of hypertonic?

the solution with a higher non-penetrating solute concentration

What is the definition of hypotonic?

the solution that has a lower non-penetrating solution concentration

What is the definition of Isotonic?

non-penetrating solute concentration is equal on both sides of the membrane

In the diffusion experiment, what was inside the beaker?

water and iodine

In the diffusion experiment, what was in the bag? What bag was used?

glucose and starch; dialysis tubing bag

In the diffusion lab, what does the benedict's reagent test for?

the presence of glucose

In the diffusion lab, what does the iodine test for?

the presence of starch

In the diffusion lab, what does the iodine test for?

the presence of starch

In the diffusion lab, what did we use to tell if starch was present?

in the diffusion lab, we used iodine as an indicator

In the diffusion lab, what color would mean that starch is NOT present?

in the diffusion lab, the color would be yellow/amber

In the diffusion lab, what color would mean that starch is present?

in the diffusion lab, the color would be blue, black, or purple

In the diffusion lab, how could we tell which solutions had glucose in them?

using the benedict's reagent as indicator

In the diffusion lab, what color would mean that glucose is NOT present?

in the diffusion lab, it would be blue

In the diffusion lab, what color would mean that glucose is present?

In the diffusion lab, it would be orange/red/brown

Is glucose a reducing or non-reducing sugar? What does this mean?

reducingsugar

In the osmosis experiment, what was the solution inside the cups?

Different concentrations of sucrose solutions (0.2, 0.3, 0.4, 0.5, 0.6)

Why measure the potato pieces before and after adding them to the solution?

Because you want to record any changes in weight

How do you calculate the percent change in weight?

(weight change/initial weight) x 100

If your potato gained weight in a solution, what does that mean?

the solute concentration is higher in the potato compared to the sucrose solution, so water will flow into the potato

If your potato lost weight in a solution, what does that mean?

the solute concentration is higher in the solution, so water will flow out of the potato and into the solution

How can you estimate the osmolality of the potato?

When the net flow of water is close to 0, you can estimate the osmolality of the potato (whichever solution is isotonic)

What is a catalyst?

a compound that speeds up a chemical reaction without being used up or altered in the reaction

What is an enzyme?

a biological catalyst

What is a substrate?

the material with which the catalyst reacts, modified during the reaction to produce new products

What is amylase? Where is it found?

in saliva and is responsible for the digestion of starch

What do enzymes help control in the body?

rate and efficiency of chemical reactions

When are enzymes most active?

optimal pH and temperature

In the enzyme lab, how did we detect starch in the solution?

iodine will turn the solution blue/ purple/ black

How do you know which is the optimal pH for amylase?

it will be the solution that starch disappeared the quickest in

What is the optimal pH for amylase?

pH= 7

What were the different temperatures used in the enzyme lab?

4, 22, 37, 80

In the enzyme lab, what was used to detect the presence of starch?

in the enzyme lab, Iodine

What was the optimal temperature for amylase activity?

37

What is the relationship between amylase and starch?

amylase is an enzyme that breaks down starch

What makes amylase break down starch faster?

optimal conditions for amylase, 37

What did we measure in the enzyme experiment?

measured the time it took for starch to disappear or be degraded by the enzyme

What is the definition of absorbance?

the capacity of a substance to absorb light of a specified wavelength

What is the definition of spectrophotometry?

method to measure light intensity passing through a substance

What is the definition of chromatography?

a process used to separate components of an mixture due to different rates of movement

What is the "mobile phase?"

the phase that moves (solvent)

What is the "stationary phase?"

the phase that does not move (porous solid)

On a plant, which part of the plant is the major site of photosynthesis?

the leaves

What is the given off as a waste product of photosynthesis?

oxygen

What is the equation for photosynthesis?

6CO2 + 6H2O ------> C6H12O6(glucose) + 6O2

What is the overview of photosynthesis?

plants absorb energy from light and convert it into energy to use with in the plant system

In the photosynthesis lab, what is he mobile phase (solvent)? Is it polar or non-polar?

Petroleum ether-acetone (9:1), it is relatively non-polar

What is the stationary phase? Is it polar or non-polar?

the chromatography paper is the stationary phase, and it is polar

What pigments did we identify in the photosynthesis lab?

chlorophyll a, chlorophyll b, carotene, xanthophyll

What is the equation for the retention factor?

distance moved by substance/distance moved by solvent

In the photosynthesis lab, what are the colors of the pigments in descending order?

Carotene, Xanthophyll, chlorophyll a, Chlorophyll b

If the mobile phase is nonpolar, will it carry nonpolar molecules further up the paper?

yes, non polar

Will polar molecules interact with the polar stationary phase and remain on the lower half of the paper?

yes, polar

What is the definition of absorption spectrum?

light absorbance of substances at different wavelengths of light

What can absorption spectrum used for?

Identify unknown chemicals

What can we use to calculate absorbance?

Spectrophotometer

Does the color of an object depend on the light reflected or the light absorbed?

reflected

Do plants absorb or reflect green light?

they reflect

Where is chlorophyll primarily absorbed?

blue and purple regions

Where is chlorophyll mainly reflected?

green and yellow regions

What is a hypothesis?

a proposed, tentative, testable explanation for an observed phenomenon

Can a hypothesis be proven?

No, it can be supported or disproven

What is a prediction?

proposed outcome made before the experiment; what you expect data will look like if your hypothesis is true and what it will look like if it were false

In an experiment, what is the control group?

usually a group kept the same throughout the experiment, helps to observe changes during he experiment and is used to compare experimental group

What is a controlled variable?

variable that is kept he same for all experimental groups

What is the control group in the Monarch experiment?

plant types and monarchs

What is an independent variable?

variable the experimenter changes or manipulates

What is a dependent variable?

variable that is measured in response to the experiment conditions and the independent variable

What is the hypothesis in the Monarch experiment?

infected female monarch butterflies preferentially lay eggs on the plants that reduce parasitic infection

What is the control in the Monarch experiment?

uninfected female monarchs

What is the independent variable in the Monarch experiment?

presence of infection within the female monarchs

What is the dependent variable in the Monarch experiment?

number of eggs on the plant with higher concentration of anti-parasitic chemicals

What plants were used in the Monarch experiment?

A. curassavica (anti-parasitic) and A. incarnata

What were the results of the Monarch experiment?

infected monarchs were shown to lay eggs preferentially on anti-parasitic milkweed when compared to uninfected monarchs

On a microscope, how much does each ocular eyepiece increase the image?

10x

What is each objective lens on a microscope?

4x, 10x, 40x, and 100x for oil immersion

What is the equation for total magnification?

eyepiece lens magnification x objective lens magnification

What is the condenser lens?

it focusses light from the lamp through the specimen

What are the coarse and fine focus adjustments do?

adjust the distance between objectives and the stage

What does FOV stand for?

field of view

What is the field of view?

the diameter of the area seen in the microscope

What does DOF stand for?

depth of field

What is the DOF?

the thickness of the specimen that may be seen in focus at one time

What is the interpupillary distance?

distance between eyepieces

What is the working distance?

distance between objective lens and specimen when in focus

What does resolution mean?

the smallest distance between two points on a specimen that can still be distinguished as two separate entities

In this equation d=(0.16lamba/N.A.) what does d stand for?

Small "d" means small distance, more detain, high resolution or simply, Resolution

What does "N.A." stand for in the resolution equation?

numerical aperture, n(refractive index) X sin alpha

Write out the resolution equation with all variables written out

d(resolution) = [(0.61 x wavelength of light)/((speed of light in a vaccuum/speed of light in a medium) x sin x half of acceptance angle of the objective lens))]

What is the refractive index (n) for air?

1

What is the numerical aperture?

the light gathering capability of the lens