Photosynthesis 2

Calculate the total number of carbon atoms represented in all of the RuBP molecules used in 1 turn of the Calvin cycle

15

How many carbon atoms total remain in the Calvin cycle at this point

15 carbon atoms are in 5PGAL that remain

Explain in detail using complete sentences how the two reactions light dependent and light independent depend on each other

18 ATP +12 NADPH from light cycle are needed to power light independent 18 ADP +12 NADP plus made in light independent are returned to light cycle

Calculate the total number of ATP and NADPH molecules used in the production of one molecule of Glucose

2 turns (9 ATP + 6 NAPH) = 18 ATP +12 NADPH

Write a chemical reaction that summarizes all of the chemical reactions in the light dependent reactions of photosynthesis starting with two water

2H2O + 2 NADP(+) + 3 ADP + 3P = O2 + 2 NADPH + 3ATP

RuBP combines with carbon dioxide to form phosphoglycerate or PGA during the carbon fixation phase of the Calvin cycle. How many CO2 molecules are used in one turn of the Calvin cycle

3

How many PGA molecules are made in one turn of the Calvin cycle

6

Identify the types and numbers of molecules that provide the free energy necessary for the reduction of the PGA Molecules

6 ATP + 6 NADPH used in reduction

Photosynthesis equation

6 CO2 +12 H20 + sunlight energy —> C6H 12O6+6O2+6 H2O

Calculate the total number of oxygen and NADPH and ATP molecules that are produced when 12 water molecules complete the light dependent Reactions

6O2+12 NADPH + 18 ATP

Calculate the total number of carbon Adams represented in all of the PGA molecules used in one turn of the Calvin cycle

6×3 is equal to 18 carbons

What shape are a symbol represents a single electron

A dark little circle

Name the embedded protein complex found in the thylakoid membrane that converts ADP to ATP using free energy from a flow of hydrogen ions

ATP synthase

Where do the ADP and NADP plus go after they are used in the Calvin cycle

Back to the thylakoid to be recycled in light dependent

Define the term carbon fixation.

CO2 is removed from the air and "fixed" into larger molecules within plant —> produces PGA, which uses ADP and NADP to produce PGAL which 1/6 of is used to make glucose and other bio molecules

Photosynthesis occurs in two parts the light dependent reactions and light independent reactions what is another name for the light independent

Calvin cycle

What substances are the reactants in photosynthesis

Carbon dioxide CO2 and water H2O

What are the three phases of the Calvin cycle

Carbon fixation, reduction and regeneration

Although photosynthesis does produce some ATP these molecules are not used to do the work of the plant cells what other process occurs in the cells that provides the ATP necessary to do cellular work such as make proteins divide cells and move substances across membranes

Cellular respiration uses glucose made here in photosynthesis to produce ATP

The structure inside the organelles are called thylakoids. What compound necessary for photosynthesis is contained in the thylakoid

Chlorophyll

What compound is best able to absorb light energy from the sun and convert it into chemical energy

Chlorophyll absorbs light and releases an electron

What is the name of this organelle

Chloroplast

The light dependent reactions include an electron transport chain system that works in a very similar fashion to the electron transport chain in respiration. Briefly describe how this system works and what job it performs in the light dependent reactions. You should include a discussion about concentration gradient

ETC uses energy from excited electrons to move hydrogen across the thylakoid membrane in direction that is against concentration gradient. This produces high concentration of hydrogen ions inside the thylakoid membrane.

Once the chlorophyll molecule has released electrons it is no longer useful until those electrons are replaced according to the model what is the source of replacement electrons for these released from photosystem 1

Electrons from photosystem two that have completed ETC

The light dependent reactions of photosynthesis include three major

Excited electrons leaving chlorophyll and reduce NADP plus into NADPH Excited electrons moving through the electron transport chain provide the free energy needed to pump hydrogen ions into the inner thylakoid Hydrogen ions flowing out of the thylakoid via a Protein channel Provide the free energy needed to convert ADP to ATP

How many PGAL molecules continue on to the regeneration phase of the Calvin cycle

Five

How many carbon atoms are in each RuBP molecule

Five

What substances are produced during photosynthesis

Glucose C6 H 12 O6 & oxygen O2

Is photosynthesis an endergonic or exergonic reaction

It absorbs energy so it is endergonic because product G3P has more energy than the reaction. Reaction has sunlight on left side meaning it must be absorbed

Why is it necessary to have six CO2 entering the chloroplast

It takes six carbons to make one glucose and those carbons come from six CO2s.

Using the Information from this activity explain why the question above is a vastly over simplified representation of the actual Process

It's very complex many reactions that are separated specially in temporarily. The equation implies one step to come bind water and CO2 to make glucose and oxygen

Is carbon dioxide involved in the light dependent reactions

No Comes in Calvin cycle in the stroma with carboxylation of RuBP

Is the total number of carbon atoms present in the Calvin cycle changed during the reduction Phase

No PGAL has 18 carbons Which is the same as PGA molecules

Are the three carbon atoms that enter the cycle as carbon dioxide and the three carbon atoms that leave the cycle as PGAL the same

No it may be that none of the carbon atoms from carbon dioxide were incorporated into a molecule of PGAL that leaves the cycle. It is also possible that one of the carbon atoms from the carbon dioxide will become part of a PGAL molecule that leaves the cycle. Eventually all of the carbon atoms that enter the cycle will leave as part of a PGAL molecule but they must wait their turn.

In the photosynthesis reaction in the Equation 12 water molecules are shown as reactance but six water molecules are shown as products. Are any of the 12 water molecules products of the light dependent reactions

No the LDR brakes water apart instead of making it

Photosynthesis is typically represented by simply equation 6CO2 +6 H2O plus light yields C6 H 12O6+6O2. Compare and contrast the simplified equation with the one represented before

Only shows net change in water not input or output

Explain where the hydrogen and oxygen atoms in these water molecules originated

Oxygen came from water removed from PGA turning into PGAL while hydrogen ions came from NADPH reducing to NADP +

Describe specifically how the structures of the two molecules PGA and it PG AL are different

PGA loses one oxygen atom as it turns into PGAL

Referred to the Reduction phase of the Calvin cycle. What molecule does the PGA molecule turn into during this phase of the Calvin cycle

PGA turns into PGAL (G3P)

Light dependent reactions electrons are released from molecules in two ways. Find two places where electrons are released from chlorophyll bio photon of light from the sun

Photosystem 2 P680 and photosystem 1 P700

Name the embedded proteins complex found in the thylakoid membrane that uses excited electrons to reduce NADP plus into NADPH

Photosystem one

Name the embedded protein complex found in thylakoid membrane that provides excited electrons to the electron transport chain

Photosystem two

Is this organelle more likely to be found in animal cells or plants cells

Plant cells

Water is a product of the reduction phase of the Calvin cycle. How many water molecules are produced

Six

Under each molecule in the equation below indicate whether it is involved either used or produced in the light dependent reactions were the Calvin cycle

Six CO2 (used in Calvin) +12 H2O (used in light dependent) yields C6 H 12O6 (produced in Calvin)+6O2 (produced in light dependent photolysis) +6 H2O (produced in Calvin)

In what part of the chloroplast do light independent reactions occur

Stroma

Where in the organelle are these Molecules stored before they are used in photosynthesis

Stroma

Throughout photosynthesis energy is transferred from light to several molecules with increasingly higher potential energy. Use the words below to summarize the order in which the energy flow occurs

Sun to electrons to ATP to glucose

What is the energy source for Photosynthesis

Sunlight

Where do the ATP and the NADPH produced during the light dependent reactions go when the process is Complete

The Calvin cycle (light independent)

Explain what happened to the carbon atoms from the carbon dioxide molecules that entered the Calvin cycle

The carbon from CO2 was incorporated into PGA

When algae are undergoing photosynthesis the concentrations of various molecules change within the cells these concentrations can be monitored and graft in complete sentences explain the shape of each line on the graph

The concentration of CO two starts off high because it is the reactant and then steadily and then steadily declines when it is used in photosynthesis The oxygen concentrations start slow and steadily increases as it is produced RuBP is constantly recycled so it remains fairly constant, after initial full from resting state of no Calvin cycle activity

According to the model what is the source of replacement electrons for those released from photosystem two

The splitting of water molecule

How many RuBP molecules are used in one turn of the Calvin cycle

Three

Identify the types and numbers of molecules that provide the free energy necessary for the regeneration of these Molecules

Three ATP

What molecules are re-generated in this phase of this cycle

Three RuBP

How many total carbon atoms leave the Calvin cycle before the regeneration phase

Three carbons leave as 1 PGAL (G3P)

In what part of the chloroplast do light dependent reactions occur

Thylakoid

How many PGAL molecules will it take to make one molecule of glucose

To PGAL (G3P) Because each has three carbons

How many turns of the Calvin cycle will it take to make one molecule of glucose

Two turns of Calvin makes one glucose

What happens to the PGAL molecule that does not continue on in the Calvin cycle

Used by other pathway to make glucose etc. and other biomolecules

When the electrons are released from water molecules what other products are formed

oxygen evolving complex on inner thylakoid side of photosystem two