BIO lab: chapter 3

PASSIVE TRANSPORT

- DOES NOT REQUIRE ENERGY (DIFFUSION)

ACTIVE TRANSPORT

- REQUIRES ENERGY

When testing the temperature of catalase, why did the enzyme catalase work best at 37°C? (Select all that apply.)

-Catalase works best at human body temperature. -Normal human body temperature is 98.6°F, which equals 37°C.

•ISOTONIC ENVIRONMENT:

-IS A BALANCED ENVIRONMENT, WHERE THE CONCENTRATION OF WATER ON BOTH SIDES ARE EQUAL. -NO MOVEMENT

OSMOSIS:

-PASSIVE TRANSPORT -MOVEMENT OF WATER THROUGH SEMI-PERMEABLE MEMBRANE FROM THE POINT OF HIGHER CONCENTRATION TO LOWER CONCENTRATION

•HYPOTONIC ENVIRONMENT:

-WHEN THE CONCENTRATION OF WATER SURROUNDING A CELL IS HIGH -WATER MOVES INTO THE CELL CAUSING IT TO SWELL

•HYPERTONIC ENVIRONMENT:

-WHEN THE CONCENTRATION OF WATER SURROUNDING A CELL IS LOW -WATER MOVES OUT OF THE CELL, CAUSING IT TO SHRINK

can cross the membrane without aid of membrane protein

-carbon dioxide gas -oxygen gas -glycerol -nonpolar molecules -lipid soluble molecules

Require Membrane Proteins to Cross the Membrane

-sugars such as starch -polar molecules -amino acids such a tryptophan -ions toward areas of a higher concentration

Frequently, transplanted organs are rejected by the recipient's body. How is this reaction related to plasma membranes?

Each person has a unique set of carbohydrate chains attached to his or her plasma membranes.

Head:

Hydrophilic (Polar region) likes water

-Tail:

Hydrophobic (Non-polar region) doesnt like water

When Elodea leaves were placed in 10% NaCl, what was the result?

The cell membrane shrank away from the cell wall because the solution was hypertonic.

The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of _____.

endocytosis

Water placed in a beaker does not require a label.

false

When examining tonicity in Elodea cells, it was important to view the cells immediately after creating your wet mount slide.

false

The best way to carry multiple test tubes is _____.

in a test tube rack

Tonicity

is the comparison of relative concentrations of two solutions, separated by a selectively permeable membrane.

Based on your procedure from the pH enzyme lab, how can you accurately measure how pH alone affects an enzymes ability to function?

same amounts of enzymes and different pH values

Effect of temperature

•ENZYME: PROTEINS THAT ACT AS A CATALYST, TO ACCELERATE THE RATE OF CHEMICAL REACTION •THE EFFECT OF TEMPERATURE ON ENZYME •MOLECULES MOVE FASTER AT HIGHER TEMPERATURE •CHANCES OF COLLISION INCREASES •OPTIMUM TEMPERATURE (NOT TO HIGH AND NOT TO LOW) •NORMAL BODY TEMPERATURE: 37 DEGREE C

MEMBRANE & STRESSORS

•EXTREME TEMPERATURE •EXTREME pH •CHEMICALS •ORGANIC SOLVENTS

MEMBRANES

•FORMS BARRIER- CONTROLS MOVEMENT OF SUBSTANCES •PROTECTS- ENCLOSE ORGANELLES OR OTHER CELL STRUCTURES •WE WILL TALK ABOUT THOSE MORE NEXT WEEK •PRIMARILY CONSISTS OF PHOSPHOLIPIDS (FATS MOSTLY) •A CELL WALL IS NOT A MEMBRANE, IT IS A LITTLE DIFFERENT

selective permeable

•PHOSPHOLIPID BILAYER = SELECTIVELY PERMEABLE •ALLOWS O2 CO2, WATER, AND SOME OTHER THINGS (SMALL, NONPOLAR, AND SOLUBLE IN LIQUIDS) •PREVENTS LARGE, POLAR AND NON SOLUBLE IN LIQUIDS (SALTS AND SUGARS) •IF THESE THINGS NEED TO GET IN AND OUT THERE ARE PUMPS AND CHANNELS FOR THEM

effects of pH

•pH AFFECTS THE RATE AT WHICH AN ENZYME CAN BIND ONTO SUBSTRATE •ENZYMES ARE ACTIVE WITHIN A CERTAIN PH RANGE •OPTIMUM RANGE = NEUTRAL (NOT TO HIGH AND NOT TO LOW) •pH: 7 NEUTRAL •pH: < 7 IS ACIDIC •pH: > 7 IS BASIC