Experimental Plant Science Test 3

1.  Define transpiration.

Movement of water and mineral nutrients from soil to atmosphere in plants 

2. Define evapotranspiration. 

Landscape-level movement of water from soil to atmosphere 

3. What is controlling transpiration? Explain how it is being controlled.

Turgid guard cells 

4. Why are stomates generally open during the day?

It is open during the day for photosynthesis and closed at night to conserve water. 

5. What type of photosynthesis does xerophytes have? 

CAM photosynthesis 

6. How does H2O move in and out of guard cells?

When potassium enters the stomates, the water enters, opening the cell. When potassium is released, the cell is closed with less water. 

7. What are the leaf adaptations to growing in arid environments? Function? 

• Thick cuticle

• Long dermis

• Hairs

• Sunken stomates

8. What are cortical cells composed of? What is their function?

Cellulose

To absorb waters

9. Explain the transpiration-cohesion theory.

Water has cohesive and adhesive properties due to its polarity

10. What makes up water’s free energy?

Solute and pressure potential 

11. What is the sign of solute potential?

0 or (-)

12. What happens when solute concentration increases?

Decreases solute potential/makes it more negative

13. What is the sign of pressure potential? What is the name of the potential? 

Positive

Turgor pressure

14. What are the major essential nutrients? 

• Nitrogen

• Phosphorus

• Potassium

• Magnesium 

• Sulfur 

15. What does Nitrogen do? 

Forms proteins, nucleic acids, and chlorophyll

16. What does P do? 

Ormes nucleotides, nucleic acids, and phospholipids 

17. What does K do? 

Regulating guard cells

18. What does Mg do?

Chlorophyll

19. What does S do?

Certain amino acids

20. What does Ca do? 

Component of plant cell walls 

21. Why is the production of hydroponic tomatoes important?

It has better pest control and less heavy and expensive 

22. What is phytoremediation used for? 

The use of plants to clean up contamination from soils, sediments, and water. These plants are then burned after the plants absorb all the metals

23. Where does the translocation of sugars occur? 

It occurs in living phloem sieve tube members

24. Is ATP required for the translocation of sugars? 

Yes 

25. What does the translocation of sugars do? 

Primarily moves sucrose and other organic compounds from a source(where photosynthesis occurs) to a sink(where no photosynthesis occurs)

26. What is the pressure flow hypothesis? 

The mechanism that explains the translocation of sugars from source to sink

27. How does water and mineral nutrient transport differ from sugar transport in vascular plants?

Water and mineral transportation relies on solute and pressure potential. No ATP is required and is transported via xylem. Vascular plants need ATP in order to be transported and need phloem to transport. 

28. What two plants provide virtually all the commercial sucrose worldwide?

Sugar cane and sugar beat

29. What is the range that plants use light from?

400-700 nm 

30. Which pigments are the primary ones? 

Chlorophyll a P680/P700

31. List accessory pigments.

• Rest of chl a

• Chl b

• Carotenoids: 

  • Carotenes (orange) 

  • Xanthophylls (yellow)

32. Where are pigments and protein complexes formed?

In the thylakoid membrane

33. What portion of Chlorophyll a and b is hydrophobic and hydrophilic?

The tail is hydrophobic and the body is hydrophilic 

34. Are carotenoids hydrophobic or hydrophilic? 

Mainly hydrophobic

35. In fall, why do green pigment/ chlorophyll break down?

Due to the lower levels of nitrogen, the green pigment begins to break down while the carotenoid doesn't since they use CO2. 

36. What is the limiting growth nutrient in plants?

Nitrogen

37. Why don’t carotenoids break down during the fall?

Because CO2 is easy for the plant to get

38. What are the two phases of photosynthesis and where do they occur?

Light reactions (photochemical phase): thylakoid membrane 

Calvin Cycle (biochemical phase): Stroma 

39. What happens during carboxylase?

CO2 enters the plant 

40. What happens during oxygenase.

When O2 can fit into the active site 

41. What enzyme is responsible for carbon fixation in the C3 cycle?

Rubisco 

42. Explain the process of photorespiration, and is it good for the plant?

Rubisco catalyzes the combining of O2 to RuBP (the oxygenase activity)

It is an inefficient process since an Oxygen is taking the slot of a Carbon

43. Where is Rubisco 4mM found?

Stroma 

44. Why is Rubisco 4mM unique? 

It is unusual since the enzyme is more abundant than the substrate since it is a slow enzyme than most. There also needs to be an abundance of Rubisco to make sure that carbon fixation is always occurring. 

45. What is the most abundant protein on earth? What percentage does it make up the leaf? 

Carbon is the most abundant and it makes up 25% of the leaf

46. How many times faster does rubisco fix CO2 than O2?

80 times

47. What is the ratio that CO2 outruns oxygenation?

3:1

48. In what environments do plants utilize the C4 Cycle?

In tropical grasses with warm season prairie grasses 

Mainly monocots

49. Why do some plants have the C4 cycle over the C3 cycle?

Due to warmer climates

50. Explain what happens during the C4 cycle.

Increases CO2 concentration in bundle sheath cells. Plants can rescue photorespiration and water loss in hot, dry environments 

But it costs ATP (less efficient if environment not hot and dry)

51. What environment do plants use the CAM cycle? 

Arid environments

52. When are stomates open in plants that use the CAM cycle?

At night

53. What is the initial carboxylating enzyme of the CAM cycle? 

PEP carboxylase 

1. What are the four categories of macromolecules in living organisms? 

• Carbohydrates

• Nucleic acids

• Proteins

• Lipids 

2. Why are there only three macronutrients in human nutrition? 

Nucleic acids are very low in amount in food compared to the other three

3. How many kilocalories are their carbohydrates and proteins per gram? 

4 kilocalories

4. How many kilocalories are in fat per gram?

9 kilocalories 

5. What are common monosaccharides? Glucose and Fructose 

6. What are common disaccharides?

Sucrose 

7. What are common polysaccharides?

Starch

8. Why is cellulose considered fiber?

No energy is imputed into the plant, but there are nutrient benefits

9. Which fibers are insoluble?

Cellulose and lignin

10. Which fibers are soluble?

Pectin and mucilage

11. What does gut bacteria do?

They ferment soluble fiber to butyric acid, regulating glucose, reduces cholesterol, and reduces occurrence of colon polyps

12. What are essential amino acids? Where do they come from?

They are the amino acids we can’t produce. We get them through the foods that we eat.

13. Why aren’t plant proteins typically “complete?”

When they don’t have all the essential amino acids in one plant

14. What proteins are complete?

Meat, dairy, and mushrooms

15. How can a vegan get complete proteins? 

By eating a variety of different plants

16. What disease can gluten trigger?

Celiac disease which leads to degradation of the intestinal lining

17. Are lipids soluble or insoluble in water?

Insoluble 

18. What are the structures that make up a lipid?

One glycerol and three fatty acids

19. What is the difference between saturated, monounsaturated, and polyunsaturated lipids? Which one do plants have?

Saturated has no double bonds, monounsaturated has one double bond, and polyunsaturated has two or more double bonds. 

Typically polyunsaturated except for coconut and palm oil

20. What is cholesterol?

Steroids absorbed from animal sources or synthesized in liver

21. What does HDL do?

Good carry cholesterol from arteries

22. What does LDL do?

Bad deposits cholesterol in arteries

23. What are trans fats? What does it increase?

Artificially produced by hydrogenation of vegetable oils. 

It increases CVD and T2DM

24. Why are trans fats made?

It’s cheaper and easier to obtain than animals. It also tastes better and gives texture to many foods

25. What are micronutrients?

Organic vitamins and inorganic minerals

26. What are vitamins?

Many are coenzymes

27. List the fat soluble vitamins.

• A

• D

• E

• K

28. Which vitamins are water soluble?

B-complex and C

29. Some people mega-dose vitamins to ensure better health. What is the practical effect of vitamin solubility?

Fat-soluble vitamins can build up toxic levels since they are not easily excreted. Water soluble vitamins are easily excreted, so they don’t build up in the body.

30. What can occur from a vitamin D deficiency?

• High BP

• Asthma/Wheezing

• Depression and schizophrenia

• Aches and weakness in the muscles

• Osteoporosis 

31. What deficiency is more likely for vegans?

Niacin and B12

32. Which mineral deficiency can lead to osteoporosis?

Calcium

33. Since micronutrients are required in much smaller amounts than macronutrients, are they any less important to the human diet?

No, they are still important

34. What can an overconsumption of processed carbohydrates lead to?

High BP and CVD

35. Which fats should be consumed?

Omega 3 fish oil

36. What are some U.S. Diet concerns?

• Salt consumption

• Eating wrong fats

• Not eating phytochemicals for cancer prevention 

• High glycemic index food 

37. What are Michael Pollan’s 7 rules for eating?

• Don’t eat anything your great grandmother wouldn’t recognize as food

• Don't eat anything with more than five ingredients

• Shop the perimeter of the grocery store

• Don't eat anything that won’t eventually rot

• Always leave the table a little hungry

• Eat food with family and friends 

• Don't buy food where you buy you gasoline

1. When did Homo sapiens evolve in eastern Africa?

200,000 BP

2. When did humans start to settle in permanent locations and use agriculture?

End of the Paleolithic (10,000 BP)

3. What is the time Homo sapiens used agriculturalists? 

5% of the existence of Homo sapiens

4. Describe the paleolithic diet.

A diet that emphasizes foods that humans might have eaten during the paleolithic era

5. What is the paleo diet hypothesis? 

Humans evolved to eat and harvest meats, fruits, and seeds not domesticated grains

6. What could be problems with diets emphasizing grain products? 

Missing on proteins and nutrients from meat, fruits, and vegetables

7. Why are pollen, fiber, seeds, and phytoliths used in archeology to determine ancient diets?

It shows the types of plants there once was, which can give us insight on the diets humans once consumed 

8. Where did the modern foragers Kung live? How long?

Lived near Kalahari Desert of southern Africa for 10,000 years

9. How many plants and animal species were utilized?

100 plant and 50 animal species

10. Explain the success of foraging as a survival strategy for early humans. 

Since they had such a variety of plants and animals in their diet, they were able to consume all the needed nutrients and vitamins they needed

11. Where was early agriculture done in the near east? 

In Fertile Crescent by Jarmo

12. What plants were being domesticated in the Fertile Crescent? 

Wheat and barley 

13. Why were cats and dogs domesticated? 

Cats were domesticated to catch rodents while dogs were used for hunting and protection

14. Where and when was rice and silkworm domesticated? 

In 11,500 BP in the far east

5000 BP

15. How was rice domesticated?

Nonshattering head of the rice was done by caching one nucleotide in its DNA sequence 

16. Fruits of wild cherry trees are sour tasting while domesticated cherry fruits are sweet. Why?

It is a trait that people liked, so it was enhanced 

17. What is Vavilov’s hypothesis? What is some recent evidence? 

Greatest diversity of a crop would most likely be the center of origin. Domestication of certain crops occurred more than once or occurred over vast regions