Lab Mid: Summary qu

Question 1

dr. smith wants to examine whether a new drug increases the maze running performance of older rats. Dr. Smith teaches two groups of older rats to find a piece of rat chow in the maze. One group of rats is given the new drug while they are learning the maze. The second group is not given the drug. One week after having learned the maze he retests the rats and recorders how long it takes them to find the rat chow. Write a hypothesis and identify the control, independent & dependent variable,

Answer 1

Hypoth: If given the new drug, the rats will have a have a higher maze running performace
IV: Drug presence
DV: maze running time
Control: Rats without the drug

Question 2

How many times more or less H+ would be present in a solution with a pH of 8 vs. a pH of 5

Answer 2

x1000 less

Question 3

How many times more or less H+ would be present in a solution with a pH of 2 vs. a pH of 4

Answer 3

x100 more

Question 4

which household item has the highest pH

Answer 4

Amonia

Question 5

Human blood has a pH of 7.35-7.45, Does this mean that human blood is slightly acidic or slightly basic

Answer 5

slightly basic

Question 6

When lemon juice (an acid) is added to a buffer, the pH remained constant for some time. describe how the buffer was able to accomplish it

Answer 6

the base in the buffer abosorbed the H+ that was added

Question 7

If ammonia was added to a buffer, describe what we might expect to observe in pH change

Answer 7

The pH would eventually begin to raise

Question 8

Solution A has a pH of 6 while solution B has a pH of 2. This means that solution A has _______x fewer hydrogen ions than solution B

Answer 8

10,000x fewer

Question 9

Solution C has a pH of 7, while solution D has a pH of 10. This means that solution D has ______x fewer hydrogen ions than solution C

Answer 9

1,000x fewer

Question 10

When using benedicts reagent, what is indictated by a color change from blue to red/orange?

Answer 10

positive

Question 11

what must be done to the test tubes containing the bendicts reagent and solutions before observing final color

Answer 11

it has to be boiling

Question 12

Which test tube contained the highest amount of simple sugars in exercise 3

Answer 12

Glucose

Question 13

Regarding the benedict’s test, which sample is the positive control and which sample is the negative control:
glucose, oil, or water

Answer 13

Neg: water
Pos: Oil

Question 14

Which reagent is used to detect the presence of complex carbohydrates (starches) in a solution

Answer 14

Iodine-potassium Iodide

Question 15

Regarding the test for complex carbohycrates (Exercise 3), which test tube is the positive control? Explain whether any of the remaining tubes may serve as a negative control
Potato flake, water, sucorse solution, glucose solution

Answer 15

Neg: water
Pos: Glucose
Since we know that the other are negative, we can use them as controls

Question 16

Which reagent is used to detect proteins in a solution?

Answer 16

biurets reagent

Question 17

Regarding the test for proteins in a solution, identify which samples are the positive control and the negative control:
Albumin, starch, water

Answer 17

Pos: Albumin
Neg: water

Question 18

Explain why Sudan IV changes color when added to il, but not glucose. Which sample was the control?

Answer 18

Oil has lipids and glucose doesn’t. Oil was the control

Question 19

Explain how to distinguid prokaryotic cells from eukaryotic

Answer 19

Prokaryotic are smaller, have a cell wall, and no mitochondria. They also have pilli and sometimes a capsule

Question 20

Which cell was the only anucleate cell viewed? explain why it many be benefical for this cell type to lack a nucleus

Answer 20

The red blood cell is anucleate and lacking a nucleus allows them to have a concave shape and therefore higher surface area. It also allows the cell to carry more hemoglobin and therefore carry more oxygen

Question 21

Describe what it means to say that a cell is squamous. how does the squamous shate relate to the function

Answer 21

flat cell, it allows the cell to cover a surface for protection

Question 22

Explain why plant cells have a cell wall surrounding the cell membrane while animal cells only have a membrane

Answer 22

For structure and support, it allows teh plant cell to have its rectangular shape

Question 23

Explain how the structure of the neuron relates to its function of sending electrical signals

Answer 23

The “arms” on the star shaped cell helps it communicate with other cells easier

Question 24

Human red blood cell size is abt 7.5um-8um. Human capillaries are abt 8um in size. Explain what these facts suggest abt the relationship btw structure and function of the red blood cell

Answer 24

Capillaries are extremely narrow, allowing only1 rbc at a time. The flexible biconcave shape of red blood cells enables them to squeeze through capillaries, facilitating efficient gas exchange. This ensures oxygen delivery and carbon dioxide removal

Question 25

Prokaryotic cells contain DNA but lack a nucleus. Describe how a prokaryotic cell stores its DNA

Answer 25

it is stored in the nucleiod region as one long chromosone

Question 26

Explain why sketetal muscle cells and sperm cells contain a very large number of mitochondria

Answer 26

They need alot of energy for alot of movement

Question 27

Explain why both mitochondria and chloroplast are found inside a plantcell

Answer 27

to make, store, and convert energy mitochondria provide energy, while chloroplasts enable photosynthesis in plant cells

Question 28

Briefly describe how gram pos and gram neg cell walls differ structurally

Answer 28

The cell wall of gram pos has more peptidoglycan (90%) while the gram neg has less (20%) and a second outermembrane

Question 29

What color does crystal violent stain gram positive bacteria

Answer 29

purple

Question 30

What color does crystal violent stain gram neg bacteria

Answer 30

purple

Question 31

What color is gram positive bacteria after decolorization

Answer 31

purple

Question 32

What color is gram negitive bacteria after decolorization

Answer 32

clear

Question 33

What is the color of gram negative bacteria after the safranin counterstain

Answer 33

red

Question 34

What is the color of gram pos bacteria after the safranin counterstain

Answer 34

purple (it was not decolorized)

Question 35

What is the color of gram negative bacteria after using iodine mordant

Answer 35

purple

Question 36

Why would scientist perform a gram stain in the lab or clinical setting

Answer 36

to make sure a proposed antibiotic would be recepted to the bacteria since the cell membrane differs between the two

Question 37

What morphology did the gram positive bacterial have? what was the morphology of the gram negative bacteria

Answer 37

Pos: Round cluster: Staphylo coccus neg: rod cluster: strepylo baccillis

Question 38

The bacteria used in Exercise 6 is staphylococcus epidermis and E. coli. Which was gram positive and which is gram negitive. What color was each after the staining process

Answer 38

Pos: staphylococcus epidermis; purple Neg: E. Coli; red

Question 39

Describe the look of red blood cells when exposed to the isotonic solution, why do they look this way?

Answer 39

they appear normal, this is because this is the solution they prefer and have equal movement in and out of the cell

Question 40

Describe the look of red blood cells when exposed to the Hypertonic solution, why do they look this way?

Answer 40

they are shriveled (crenated) since the water is drawn out of the cell

Question 41

Describe the look of red blood cells when exposed to the Hypotonic solution, why do they look this way?

Answer 41

The cell is swollen since it absorbs the water and eventually lyses

Question 42

Explain what it means to say that a solute moves down the concentration gradient

Answer 42

it moves from high concentration to low concentration; if there is less concentration inside the cell (hypotonic) the solution outside is going to move to the lower concentration to reach equalibrium

Question 43

Predict what would happen if a red blood cell was placed into a 1.2% NaCl soltion (body is 0.9% NaCl)

Answer 43

It would shrink and crenate

Question 44

The isotonic glucose for red blood cells is 5%, what does this mean

Answer 44

there is a 5% concentration of glucose in the red blood cell

Question 45

What would happen to a red blood cell if it was placed into a 5% glucose solution (body is 5% glucose)

Answer 45

nothing, it is isotonic and at equalibrium

Question 46

Describe what would occur if a red blood cell was exposed to a 8% glucose solution

Answer 46

It would shrink and crenate

Question 47

What would happen to a flaccid potato strip if you were to place it inside a Petri dish containing pure water (0% NaCl) for 30 minutes

Answer 47

The cells would swell since there is a higher concentratoin of water outside

Question 48

Describe the difference between the size of the central vacuole in the Elodea cells in hypotonic solution vs. the Elodea cells in hypertonic

Answer 48

Elodea has a lager vacuole in the hypotonic soluton because it absorbs the water

Question 49

Did the entire elodea cell shrivel in the hypertonic solution? why or why not

Answer 49

yes, there was more solution outside

Question 50

What is the 'optimal' temp for catalase?

Answer 50

37 degrees celcius

Question 51

Explain the reaction rate you observed in ice water for exercise 8 (enzymes)

Answer 51

the reaction took slower to begin but then rapidly begain to react

Question 52

Explain the reaction rate you observed in 100 degree water for exercise 8 (enzymes)

Answer 52

The enzymes were denatured and therefore inactive

Question 53

Based on the rate of bubbling (oxygen produced), which tissue contained catalase? Liver, potato, chicken, or apple

Answer 53

Liver

Question 54

What is the optimal pH for catalase

Answer 54

7

Question 55

Explain the effects of pH or temperature for catalase activity in bacteira

Answer 55

the catalyst will denature when heated or has a significant pH change

Question 56

What represents control in exercise 9 water, yeast, glucose, combonation

Answer 56

water

Question 57

What is the independent variables in exercise 9 (fermentation)

Answer 57

solution proportion

Question 58

What is the dependent variables in exercise 9 (fermentation)

Answer 58

Gas bubble height (CO2 output)

Question 59

If the parafiml was removed, would fermentation still occur?

Answer 59

no, oxygen inhibits fermentation, cells would take glucose to form ATP

Question 60

What ratio of water, yeast, and glucose resulted in the highest rate of fermentation (fermentation lab)

Answer 60

3w, 6y, 6g

Question 61

Which steps are common to both fermentation and cellular respiration? describe how the 2 processes can have common steps

Answer 61

Glycolosis is the first step before oxygen divides the two Glycolosis is the only intake of energy for fermentation

Question 62

Which pathway (aerobic/anarobic) produces the most energy during the catabolism of glucose

Answer 62

aerobic

Question 63

Humans use mostly aerobic respiration. What is the advantage of aerobic respiration vs anaerobic

Answer 63

Aerobic produces more ATP (32 vs 2 in anaerobic)