Bio 105 Climate Change HW Mod 2

The energy released by energized electrons is used to produce ATP and NADPH.

Light Reactions

electromagnetic spectrum

describes the solar energy emitted by the sun

Scientists have been recording increased levels of carbon dioxide. The increased levels are due to

humans burning fossils fuels. Carbon that was formerly sequestered in reservoirs is now being released into the atmosphere at an alarming rate.

What is the role of carbon dioxide in photosynthesis?

Carbon dioxide is reduced to a sugar during photosynthesis.

In the stroma, electrons move through Photosystem II to Photosystem I embedded in the thylakoid membrane.

Light Reactions

What is the role of light during the light reactions of photosynthesis?

Light energy is absorbed and used to excite electrons in the pigment molecules.

Neither Photosynthesis nor Cellular Respiration

produces light energy

Both Photosynthesis and Cellular Respiration

-A metabolic process -Used by plant cells

Photosynthesis Only

-Occurs inside the chloroplast -A pathway for building sugar -Reactants are carbon dioxide and water -Products are glucose and oxygen -Dependent on light

Cellular Respiration Only

-Occurs inside the mitochondria -A pathway for breaking down sugar -Reactants are glucose and oxygen -Products are carbon dioxide and water -Used by plants and animal cells -Independent of light

Which of the following properties provides an accurate reason as to why carbon is important to living organisms?

Carbon has the ability to form long chains and complex ring structures that play an important role in forming large molecules.

Which of the following describes the principal role of photosynthesis in the carbon cycle?

Using energy from the sun, plants convert carbon dioxide from the atmosphere into chemical energy of sugars.

Light energy is captured and transferred to electrons within the chlorophyll.

light reactions

CO2 is captured and converted to glucose.

Calvin Cycle

The pathway recycles its starting materials.

Calvin Cycle

Describe photosynthesis

-Photosynthesis produces oxygen, which allows other organisms to conduct cellular respiration. -Photosynthesis produces sugars, which are used as an energy source by plants and other organisms. -In photosynthesis, the carbon used to make sugars is provided by carbon dioxide.

Calvin Cycle steps

1- carbon fixation, is the incorporation of carbon dioxide (CO₂) into ribulose-1,5-bisphosphate (RuBP). 2- , reduction, is the use of the high energy electron carriers, ATP and NADPH, to reduce carbon dioxide. 3- the starting material is regenerated

This process uses ATP and NADPH to produce sugars.

Calvin Cycle

In relation to the carbon cycle, why is photosynthesis an important metabolic process to organisms on the planet?

Carbon dioxide is converted to sugar. The sugar products of photosynthesis are used as energy by the plants, and by organisms that either eat plants or eat organisms that eat plants.

When fossil fuels are burned, they will __________.

produce large quantities of carbon dioxide that is released in the atmosphere. This will increase the effects of climate change.