Sapling Chapter 8

component of chloroplast that is the site of light-dependent reactions

thylakoids

all the events that occur during light-dependent reactions

- a concentration gradient forms as excited electrons help move H+ ions - light energy is used to excite electrons on specific chlorophyll molecules H+ ions are used to help produce energy carriers, ATP and NADPH

heterotrophs

- consumers - unable to produce organic compounds from inorganic materials - obtain their food by consuming other organisms - rely on other organisms for energy

characteristics of photsynthesis

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

Unique to Photosystem II

- the hydrogen atoms from water molecules are split, producing H+ and replacement electrons for chlorophyll molecules - energy from electrons excited in this photosystem is used to help pump H+ ions into the thylakoid for ATP production

Thylakoid

A flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy.

arrange the events of the light dependent reactions of photosynthesis

1. electrons on specific chlorophyll molecules are excited by light 2. electrons escape from chlorophyll molecules and move down an electron transport chain 3. hydrogen ions are pumped into the interior of the thylakoid 4. H+ ions pass through an enzyme as they move out of the thylakoid 5. ATP and NADPH are produced

Carotenoids

Absorb violet-blue light Reflect and transmit yellow, orange, and red light

NADPH

An electron carrier involved in photosynthesis. Light drives electrons from chlorophyll to NADP+, forming NADPH, which provides the high-energy electrons for the reduction of carbon dioxide to sugar in the Calvin cycle.

Molecules brought in and used in the Calvin Cycle

Carbon dioxide NADPH

molecules produced during the calvin cycle and leave the cycle

NADP few G3P

Chlorophyll a absorbs

blue and red light

Molecules brought in and used in the Calvin Cycle

carbon dioxide molecules carrying energy from the light-dependent reactions

photosynthesis reactants

carbon dioxide and water

in which phase of the Calvin cycle is 3PGA created

carbon fixation

molecules produced in the Calvin Cycle that leave the cycle

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

Stroma

fluid portion of the chloroplast; outside of the thylakoids

both photosynthesis and respiration.

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

molecules made in the cytoplasm from the products of the Calvin Cycle

glucose

Photosynthesis products

glucose and oxygen

both light-dependent and calvin cycle

happen inside the chloroplasts in plants

produced by light dependent reactions

high-energy NADPH and ATP

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

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

energy source for photosynthesis

light

unique to both photosystems

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

Chlorophyll b absorbs

mainly blue and orange/red light (reflects yellow-green)

molecules used and regenerated within the Calvin Cycle

most G3P RuBP

characteristics of stomata in plants

permit carbon dioxide to enter and oxygen to escape from a plant are pores enclosed by guard cells that are located on plant surfaces

Why do most plants appear green?

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

autotrophs

producers many use photosynthesis to produce organic compounds use inorganic materials to produce energy synthesize their own food

which of the following statements describe photosynthesis?

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

characteristics of cellular respiration

released carbon dioxide occurs in both plant and animal cells

Granum

stack of thylakoids

What 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

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

which statement describes the function of photosynthetic pigments in leaves

they capture light energy and remove electrons from a donor

light-dependent reactions

use H20 capture light energy synthesize ATP and NADPH generate oxygen gas

Calvin Cycle

use carbon dioxide produce sugars need ribulose bisphosphate

Needed for light dependent reactions

water, sunlight, chlorophyll