Lab 7,9 Flashcards
the membrane is selectively permeable because?
it allows only certain molecules to cross freely
diffusion
the net movement of molecules from a region of higher concentration to a region of lower concentration
osmosis
the diffusion of water across a deferentially permeable membrane from an area of higher water concentration to an area of lower water concentration
solution
contains both a solute (particles) and a solvent (liquid) that dissolves the solute
tonicity
the relative concentration of solute and solvent outside of a cell compared to inside the cell
which substance crosses membrane? iki or starch
Iki - blue
how would you know if a potato core gained water?
it would be harder and have a more dense feel to it
overall equation for photosynthesis
CO2 + H2O –(solar energy)–> C6H12O6 + O2 + H2O
Where does photosynthesis takes place>
Chloroplast
Chloroplast
where plant pigments absorbs solar energy
the principal pigment in advanced plants is?
chlorophyll (chl a and chl b)
Describe how chlorophyll absorb energy
they absorb energy in the red and blue portions of the elctromagnetic spectrum and reflects green wavelengths
what is the point of accessory pigment
to maximize the amount of light energy absorbed
Carotenoids and xanthophylls
- orange and yellow pigments
- two common accessory pigments in green plants
chromatography
a technique that separates molecules from each other on the basis of their solubility (ability to dissolve) in particular solvents
- allow qualitative determination of the presence of accessory pigments in green leaves
leaf experiment pigment from most soluble to least soluble
Chlorophyl b, a, xanthophyll, carotenes
the three major groups of producer organisms
autotrophs
plants
cyanobacteria
algae
respirometer
device for measuring the amount of gas given off and or consumed
What gas is produced during photosynthesis? during fermentation?
Oxygen, Carbon dioxide
Describe Experiment 7 activity 1
dialysis bag all solute with glucose and starch diffused into a beaker containing H2O and IKI
- The IKI from the beaker diffused into the bag and interacted with the starch to turn the dialysis bag into blue, which meant that the glucose diffused into the beaker from the bag. When boiled for 10 min, the color turned orange proving positive for glucose.
Describe lab 7 activity 2 - osmotic response of cell
potato core in solution of salts in 0, 1, 2, 4%
the one in no solution of salt absorbed more water which means that the solution is hypotonic to the potato
- it lost weight on 1 2, 4, which means that the solution is hypertonic to the core
- isotonic is where it reaches at 0
plasmolysis vs crenation
plasmolysis occurs on plant cells with cell walls
- the cell wall doesnt shrink, only the plasma membrane does
Crenation is for cells that does not have cell walls
- the whole cell shrinks
Describe Lap 9
paper chromatography to note the occurrence of different pigments in green plants, quantitatively determine the effect of increasing light intensity on photosynthetic rate, and observe a demonstration of the uptake of carbon dioxide gas by an aquatic producer (elodea)
lab equipment used in lab 9
manometer tubes with test tubes
dropper bottle of sodium bicarbonate (20 drops each tube)
two write clamps
elodea with water and sodium bicarb in one - other is just water with bicarbonate
and light
which are the essential pigments
chlorophyll a and b
which are the accessory pigments
orange and yellow, carotenes and xanthophylls
Carbon dioxide fixation
- during the 2nd stage of photosynthesis, the plants takes up?
CO2 and reduces it to a carbohydrates, such as glucose C6H12O6.
- the CO2 should disappear around elodea as photosynthesis happens
Phenol red
a ph indicator that turns yellow in an acid and red in a base
- when carbon dioxide combines with water, it forms carbonic acid
Activity 3 Carbon dioxide fixation
The start solution is phenol red with elodea and just phenol red. The solution is blue acid, as air is introduced (CO2) color changes to green, turns more towards base. As the elodea photosynthesis the CO2, it introduces Oxygen to level off the pH level of the solution and turn it back to acid.
Passage of molecules into and out of cells is regulated by?
plasma (cell) membrane
