CH. 8 Sapling HW

Molecules produced in the Calvin cycle that leaves the cycle

- 3-carbon molecules that store energy - energy-carrier molecules that have lost some energy

Molecules produced during the Calvin cycle that leave the cycle

- NADP+ - a few of the glyceraldehyde 3-phosphate (G3P)

Unique to photosystem II

- the hydrogen atoms from water molecules are split, producing H+ and replacement electrons for chlorophyll molecules - the energized electrons leaving this photosystem help pump H+ ions into the thylakoid so that they can be used in ATP production

Which statements describe characteristics of stomata in plants?

- are openings into a plant that are surrounded by guard cells - allows gases, such as CO2 and O2 to enter and escape from a plant

Molecules brought in and used in the Calvin cycle

- carbon dioxide - NADPH

Molecules brought in and used in the Calvin cycle

- carbon dioxide from the environment - molecules carrying energy from the light-dependent reactions

Choose all the events that occur during the light-dependent reactions of photosynthesis.

- electrons on special chlorophyll molecules gain energy from light - a concentration gradient forms as excited electrons help move H+ ions - H+ ions are used to help produce the energy carriers, ATP and NADPH

Classify each of the characteristics as both photosynthesis and cellular respiration.

- generates ATP - generates energy using a proton (H+) gradient - occurs in plants - requires an electron transport chain

Both the light-dependent reactions and the Calvin cycle of photosynthesis

- happen inside chloroplasts in plants

What is needed for the light-dependent reactions of photosynthesis to take place?

- light energy - water - chlorophyll - CO2 molecules

Molecules used and regenerated within the Calvin cycle

- most of the glyceraldehyde 3-phosphate (G3P) - ribulose biphosphate (RuBP)

Classify each of the characteristics as photosynthesis.

- occurs in the chloroplasts of plant cells - requires sunlight to proceed - synthesizes carbohydrates to store energy

Molecules made in the cytoplasm from the products of the Calvin cycle

- organic molecules such as glucose

Plants synthesize their own food in the form of sugars during the process of photosynthesis. Which of the following statements describe photosynthesis?

- produces sugars for the plant using the energy from sunlight - is a cellular process that occurs in the chloroplasts of plant cells - converts carbon dioxide to sugars, releasing oxygen

Classify each of the characteristics as cellular respiration.

- releases carbon dioxide (CO2) - occurs in both plant and animal cells

Light-dependent reactions of photosynthesis

- require water - capture light energy using chlorophyll - synthesize ATP and NADPH - generate oxygen gas

Unique to photosystem I

- the energized electrons are used to form NADPH after leaving this photosystem - electrons from the electron transport chain are used to replace electrons lost from chlorophyll molecules

Calvin cycle of photosynthesis

- uses CO2 - produces sugars - need ribulose biphosphate

Classify each description as applying to either autotrophs or heterotrophs.

Autotrophs: - producers - many use photosynthesis to produce organic compounds - use inorganic materials to produce energy - synthesize their own food Heterotrophs: - consumers - unable to produce organic compounds from inorganic materials - cannot make their own food - rely on other organisms for energy

Arrange the events of the light-dependent reactions of photosynthesis in the order that they occur.

Initial Event - electrons on specific chlorophyll molecules are excited by light - electrons escape from chlorophyll molecules and move down an electron transport chain - hydrogen ions are pumped into the interior of the thylakoid - H+ ions pass through an enzyme as they move out of the thylakoid - ATP and NADPH are produced Final Event

During one of the three phases of the Calvin cycle, the carbon atoms from three CO2 molecules are incorporated into three five-carbon sugar molecules called ribulose bisphosphate (RuBP). This reaction forms an unstable six-carbon intermediate which immediately splits into two three-carbon sugar molecules called 3-phosphoglyceric acid (3PGA). In which phase of the Calvin cycle does this occur?

carbon fixation

What is produced during the light-dependent reactions?

high energy NADPH and ATP

Consider what happens to energy in photosynthesis. How does this differ from what happens to energy in cellular respiration?

in photosynthesis, energy is captured from light, whereas in cellular respiration energy is transferred from storage molecules to ATP

Similarities between the two photosystems

light energy is used to excite an electron on specialized chlorophyll molecules

Why do most plant leaves appear green?

pigments in plant cells absorb blue and red light, but much of the green light is reflected

Which of the following scenarios is a direct effect of the absence of carbon dioxide during photosynthesis?

the carbon fixation stage of the Calvin cycle would be unable to synthesize the sugar 3-PGA

Which statement describes the function of photosynthetic pigments in leaves?

they absorb light energy and trap high energy electrons

Carotenoids

violet-blue

Chlorophyll a

violet-blue orange-red

Chlorophyll b

violet-blue orange-red