Chemistry Exit Ticket: Plant Chemistry

Plants Exit Ticket

College Chemistry Plants Exit Ticket Challenging 20 Questions 7 Views

Classroom Worksheet

Chemistry Exit Ticket: Plant Chemistry

Plants Exit Ticket

Name____________________________

Date________________

Score______ / 20

Grade: College

Subject: Chemistry

Topic: Plants

Time: 20 Minutes

Difficulty: Challenging

Questions: 20

Instructions:
Answer each question briefly and clearly. Show your reasoning when needed. Questions increase in difficulty, so do your best on every item. Use complete chemical names, formulas, and balanced equations where appropriate.

Skills Practiced:

Plants
Chemistry
Critical Thinking
Problem Solving

1Question

What is photosynthesis in chemical terms?

2Question

Write the balanced chemical equation for photosynthesis.

3Question

Name the main pigment in plants that absorbs light for photosynthesis.

4Question

What type of molecule is chlorophyll: carbohydrate, lipid, protein, or pigment?

5Question

Which element in chlorophyll makes it especially important for absorbing visible light?

6Question

Identify the role of water in photosynthesis.

7Question

What gas do plants take in for carbon fixation during photosynthesis?

8Question

In which part of the chloroplast does the light-dependent stage of photosynthesis occur?

9Question

In which part of the chloroplast does the Calvin cycle occur?

10Question

What is the chemical name of the storage carbohydrate synthesized by many plants?

11Question

Why do plants convert glucose into starch rather than store large amounts of glucose directly?

12Question

Explain, in one sentence, why leaves are often green.

13Question

What is the oxidation state change for carbon in carbon dioxide when it becomes part of glucose during photosynthesis?

14Question

What is the term for the chemical process in which a compound gains electrons during photosynthesis?

15Question

Balance this equation for plant respiration: C6H12O6 + O2 -> CO2 + H2O.

16Question

How are photosynthesis and cellular respiration chemically related in plants?

17Question

If a leaf is exposed to light but lacks carbon dioxide, which major photosynthetic product will be limited first: oxygen or glucose?

18Question

A student says chlorophyll is the only molecule needed for photosynthesis. Give one reason this is incorrect.

19Question

Describe how the pH changes in the thylakoid lumen during the light reactions and why.

20Question

A plant is grown in water labeled with the isotope oxygen-18 in the H2O. Where would you expect the isotope to appear first in the photosynthetic products, and why?

Answer Key

#	Answer
1	Photosynthesis is the process in which plants use light energy to convert carbon dioxide and water into glucose and oxygen.
2	6CO2 + 6H2O -> C6H12O6 + 6O2
3	Chlorophyll a
4	Pigment
5	Magnesium
6	Water is a reactant that provides electrons and hydrogen ions, and it is the source of oxygen released during the light reactions.
7	Carbon dioxide
8	The thylakoid membrane
9	The stroma
10	Starch
11	Starch is less soluble and less osmotically active than glucose, so it is safer and more efficient for storage.
12	Leaves appear green because chlorophyll absorbs mostly red and blue light and reflects/transmits more green light.
13	Carbon is reduced; its oxidation state decreases from +4 in CO2 to an average of 0 in glucose.
14	Reduction
15	C6H12O6 + 6O2 -> 6CO2 + 6H2O
16	They are complementary processes: photosynthesis stores energy by making glucose, while respiration releases energy by breaking glucose down.
17	Glucose will be limited first because carbon dioxide is required for carbon fixation, while oxygen release can still occur from water splitting in the light reactions.
18	Photosynthesis also requires enzymes, electron carriers, water, carbon dioxide, ATP synthase, and membrane structures in the chloroplast.
19	The pH decreases because protons are pumped into the lumen and released there from water splitting, making the lumen more acidic.
20	It would appear first in the oxygen gas released, because the O2 produced during photosynthesis comes from water molecules split in the light reactions.