Photosynthesis

Question 1

where does photosynthesis occcur?

Answer 1

tylakoid

Question 2

What is the stroma?

Answer 2

fluid around the thylakoid – contains the pigment chlorophyll

Question 3

_____________resides in the thylakoid membrane?

Answer 3

chlorophyll

Question 4

Photosynthesis is a ________reaction?

Answer 4

redox

Question 5

in photosynthesis______is split and the electrons and H+ are transferred to CO2 reducing it to sugar electrons increase in potential energy. the reaction is______________

Answer 5

water

endergonic

Question 6

In photosynthesis: plants convert radiant energy from the sun into chemical energy in the form of glucose and sugar. what is the formula?

Answer 6

water + CO2 + Sunlight ——> glucose + oxygen 6H2O+ 6CO2 + radiant energy —> c6h12o6 + 6o2 reverse of cellular respiration-biochem pathways aren’t the same-separate pathways

Question 7

• Light is a form of energy = electromagnetic radiation • The entire range of radiation is the electromagnetic spectrum – What we can detect as various colors = visible light (380‐750nm)
• _______ = discrete particles with a fixed amount of energy (no mass!) Why is the sky blue? Why does something appear white? Black?

Answer 7

Photons

why is the sky blue? wavelengths in blue area of spectrum reflected by particles in the air and make its way to the eye. red shirt, red reflected.

appear white-reflects everything

appear black-reflects nothing

Question 8

• ________ = substance that absorbs visible light – Different pigments absorb different wavelengths of light – Chlorophyll a & b appear green because they do not absorb wavelengths in that part of the spectrum – Why do leaves change colors?

Answer 8

pigments

Leaves are colored by molecules called pigments. The pigment that causes leaves to be green is chlorophyll. Chlorophyll is important for plants to make food using sunlight. During spring and summer when there is plenty of sunlight, plants make a lot of chlorophyll.

In autumn when it starts to get cold, some plants stop making chlorophyll. Instead, those plants break down chlorophyll into smaller molecules. As chlorophyll goes away, other pigments start to show their colors. This is why leaves turn yellow or red in fall.

The color change usually happens before the leaves fall off of the tree. Why might that be? It takes a lot of energy to make chlorophyll. If the plants break down the chlorophyll and move it out of their leaves before the leaves fall, plants save energy. The plants can reabsorb the molecules that make up chlorophyll. Then, when it’s warm and sunny enough to grow again, the plants can use those molecules to remake the chlorophyll. That way the plants don’t have to make chlorophyll from scratch.

Question 9

Light Reactions –

Convert _____ energy into _________ energy

• H2O is split to provide e‐ and H+
• NADP+ reduced to NADPH
• ATP is produced
• O2 is given off

Answer 9

light energy to chemical energy

Question 10

• Calvin Cycle (Light Independent/Dark Reactions)

– Fixes ______ from CO2 into organic molecules

– Reduces fixed carbon into sugar using the _____ and ___ from light reactions

Answer 10

Carbon

NADPH and ATP

Question 11

– ___________________: contain pigment molecules which absorb light and transfer the energy to reaction‐center complex (i.e. antenna) –

Answer 11

light harvesting complexes

Question 12

what is the equation for light reactions?

Answer 12

Light + H2O ———–> NADPH + ATP + O2

Question 13

___________________: contains a special pair of chlorophyll a molecules which can reduce the primary electron acceptor

Answer 13

reaction-center complex

Question 14

• Photosystems which capture light are located in the__________ membrane

Answer 14

thylakoid

Question 15

T/F Photosystem 2 is before photosystem 1

Answer 15

True

Question 16

Calvin Cycle • Broken down into 3 phases: – ___________ • Rubisco (RuBP carboxylase) attaches CO2molecule to ribulose bisphosphate (RuBP) – ___________ • Carbon intermediate received phosphate group from ATP • Reduced by NADPH and loses the phosphate = G3P – __________________ • Series of steps which utilize ATP to rearrange 5 molecules of G3P to regenerate 3 molecules of RuBP

Answer 16

• Uses the chemical energy stored in ATP and NADPH to reduce CO2 to sugar (G3P)

Question 17

1st phase of the carbon cycle?

Answer 17

carbon fixation Rubisco (RuBP carboxylase) attaches CO2molecule to ribulose bisphosphate (RuBP)

Question 18

2nd phase of carbon cycle?

Answer 18

Reduction

• Carbon intermediate received phosphate group from ATP
• Reduced by NADPH and loses the phosphate = G3P

Question 19

3rd phase of the calvin cycle?

Answer 19

Regeneration of Co2 acceptor

• Series of steps which utilize ATP to rearrange 5 molecules of G3P to regenerate 3 molecules of RuBP

Question 20

Cycle must occur ___ to produce 1 net G3P (Fixing 3 CO2) – Technically produces 6 G3P molecules but 5 must be used to regenerate RuBP • For 1 G3P, cycle uses 9 ATP and 6 NADPH

Answer 20

3X

Question 21

The series of reactions in the calvin cycle have to regenerate____________?

Answer 21

co2 acceptor

Question 22

What Happens to the Sugar Produced? •

~50% is used as fuel for cellular respiration

– Transported throughout the plant (only green parts of photosynthetic)

• Linked together to form _______ • Excess stored as ______ • Makes ~160 BILLION metric tons of carbohydrate per year – Equal to about 60 trillion copies of your textbook • 17 stacks from here to the sun

Answer 22

cellulose, starch