Unit 7 - Photosynthesis

Sacoglossan Sea Slug

-Can be found sunbathing on Caribbean reefs

-Feeds on green algae but can survive for more than a month without eating.

-Sea slugs store chloroplasts as they ingest different species of green algae

-The chloroplasts are stored in the slug’s digestive system and remain active for up to 4 months by
providing the slug with nutrients from photosynthesis

-Also provides camouflage by making the slug green in color

-Kleptoplasty = stolen plastids - is the term for the slugs remarkable ability.

Photosynthesis

Anchoring Phenomenon: Slug Power

With your group generate your own questions about energy capture from the following
images.

Sea Slug

Plant cell with Chloroplasts
Focus on:

-Structure, color, shape etc…

-Any relationships or similarities between the two images.

Chloroplasts

Found in plant and some protist cell

Function: Capture light energy from the sun and
convert it into chemical energy through the
process of PS

Structure:

-Thylakoids - stacked like coins, where
chlorophyll pigment resides.

-Chlorophyll - pigment responsible for
capturing light energy

-Stroma - space between thylakoids and
chloroplast membranes

A plant cell contains between 10-100 chloroplasts
per cell.

Multiple Choice

What is the primary function of chloroplasts in plant and some protist cells in regards to the flow of energy?

• Energy storage

• Nutrient absorption

• Light energy capture

• Waste removal

Multiple Choice

In what structure of the diagram is chlorophyll located and what is it called?

• 3, the outer membrane

• 2, the inner membrane

• 3, the stroma

• 5, the thylakoids

Multiple Choice

Students were asked to design an experiment to investigate the effect varying light intensities has on the number of chloroplasts present in a plant cell. Which of the following variable would be appropriately manipulated in this lab group’s experiment?

• carbon dioxide concentration

• temperature

• acidity/pH levels

• duration of light exposure

How might you refine your questions from earlier now that
you know more about the images?

Sea Slug

Plant cell with chloroplasts

Photosynthesis

Converts light energy into stored chemical energy by using sunlight to convert
carbon dioxide and water into sugars, releasing oxygen.

2 sub-processes (reactions)

-Light Reactions (light-dependent)

-Calvin Cycle (light-independent)

Inputs

-Carbon dioxide

-Water

-Light energy

Outputs

-Glucose

-Oxygen

Multiple Choice

What is the primary function of photosynthesis?

• Converting light energy into stored chemical energy

• Generating heat energy for thermoregulation

• Producing water to be used for cellular respiration

• Releasing carbon dioxide for the carbon cycle

Multiple Select

What are the inputs and outputs of photosynthesis?

• Inputs: Starch and cellulose 

  Outputs: Starch and cellulose

• Inputs: Nitrogen and phosphorus

  Outputs: Carbon dioxide and water

• Inputs: ATP and electron carrying molecules 

  Outputs: ATP and NADPH

• Inputs: Carbon dioxide, water and light energy

  Outputs: Glucose and oxygen

Multiple Choice

Which best explains the role photosynthesis plays in the cycling of energy and matter within an ecosystem?

• Photosynthesis generates heat energy, maintaining earth’s consistent temperature balance.

• Photosynthesis produces glucose and oxygen serving as the foundation for most food chains and ecosystems.

• Photosynthesis converts oxygen into carbon dioxide, supporting cellular respiration within animals.

• Photosynthesis releases water vapor into the atmospheres, contributing to cloud formation and weather patterns.

Light Reaction (Light-dependent)

-“Photo” part of photosynthesis

-Inputs: Solar energy + H2O

-Outputs: O2 (released), ATP and NADPH

-Location: in the thylakoids where chlorophyll pigment
is located

-Steps:

1.)

Light is absorbed by chlorophyll in the
thylakoid membranes of chloroplasts

2.)

Water molecules are split using the
absorbed light energy producing oxygen,
ATP and NADPH.

a.)

Oxygen is released

b.)

ATP and NADPH is used in the
Calvin Cycle

Notice that each reactant (solar energy, H2O and CO2)
are inputs during different sub-processes.

Notice that each product (glucose and oxygen)is an
output of different sub-processes.

Multiple Choice

What are the inputs required for the light reactions of photosynthesis?

• Solar energy and water

• Oxygen and glucose

• ATP and electron carriers

• Carbon dioxide and water

Multiple Choice

In what structure of the diagram do the light reactions of photosynthesis take place and what are they called?

• 4, in the stroma

• 2, in the inner membrane

• 3, on the outer membrane

• 5, in the thylakoids

Multiple Choice

Evaluate the importance of the release of oxygen during the light reactions of photosynthesis, considering its role in the cycling matter in the ecosystem.

• Oxygen release during photosynthesis is crucial for maintaining high levels of carbon dioxide

• The release of oxygen during photosynthesis has no significant impact on organisms or atmospheric oxygen levels

• Oxygen release supports aerobic respiration in organisms, providing the energy necessary for cellular processes.

• Oxygen released during photosynthesis is converted into glucose during the Calvin Cycle.

Calvin Cycle (light-independent reaction)

Synthesis part of photosynthesis

Inputs: CO2 + ATP + NADPH

Outputs: C6H12O6

Location: in the stroma of chloroplasts

Carbon dioxide from the atmosphere along with the
ATP and NADPH generated during the light
reactions are utilized to create simple sugars.

Notice that each reactant (solar energy, H2O and
CO2) are inputs during different sub-processes.

Notice that each product (glucose and oxygen)is
an output of different sub-processes.

Multiple Choice

Using the diagram, identify which structure in the chloroplast the Calvin cycle takes place in.

• 4, the stroma

• 3, outer membrane

• 2, inner membrane

• 5, the thylakoids

Multiple Choice

What are the inputs for the Calvin Cycle? 

• Light energy, CO2 and H2O

• ATP, electron carrying molecules, and CO2

• Glucose and O2

• Oxygen, ATP, and electron carriers

Multiple Choice

What is the purpose of the Calvin Cycle?

• To produce glucose utilizing ATP and electron carrying molecules.

• To produce water utilizing glucose, ATP and carbon dioxide.

• To produce oxygen by utilizing ATP to break the bonds of glucose.

• To produce ATP by utilizing glucose and the electron carrying molecules.

Photosynthesis & Cell Respiration Cycle

Multiple Choice

Describe the role of carbon dioxide in photosynthesis.

• It is released as a by product and used in anaerobic respiration.

• It is used to produce energy by breaking down glucose in cellular respiration.

• It is absorbed from the atmosphere and used to synthesize glucose

• • se 

  • It is converted into oxygen in the electron transport chain

Multiple Choice

Compare and contrast the roles of carbon and oxygen in photosynthesis and cellular respiration

• Carbon dioxide is utilized in photosynthesis to produce glucose, while oxygen is used in cell respiration to produce energy.

• Carbon dioxide is released in both photosynthesis and cellular respiration, while oxygen is only released in photosynthesis

• Carbon dioxide is taken in during cell respiration and released during photosynthesis, while oxygen is released during cell respiration and taken in during photosynthesis.

• Carbon dioxide and oxygen play similar roles in both photosynthesis and cell respiration.

Multiple Choice

Explain the relationship between photosynthesis and cellular respiration.

• Photosynthesis produces oxygen, while cell respiration produces carbon dioxide.

• Photosynthesis converts light energy,  carbon dioxide and water into glucose and oxygen, while cellular respiration converts glucose and oxygen into carbon dioxide and water.

• Photosynthesis and cell respiration are independent processes that do not affect each other.

• Photosynthesis and cell respiration both involve the breakdown of glucose to produce ATP.

Functions of Photosynthesis

Producers (autotroph)

-Enables organisms to produce their own food

-Energy production: simple sugars produced by photosynthesis
are used to generate cellular energy (ATP) through cell
respiration.

-Macromolecule formation: sugars produced by photosynthesis
can also be used to synthesize other macromolecules such as
starch and cellulose.

Consumers (heterotrophs)

-Cannot produce their own food

-Rely on consuming plants or other organisms to obtain
the materials needed for cellular functions.

-Photosynthesis provides an energy source that can be
utilized by various organisms.

Multiple Choice

Evaluate the importance of photosynthesis in the ecosystem.

• Photosynthesis is essential for the survival of all organisms as it uses light energy to create CO2 which provides the primary source of energy for the ecosystem.

• Photosynthesis is only important for producers.

• Photosynthesis is essential for the survival of all organisms as it provides the primary source of energy for the ecosystem.

• Photosynthesis is minor process in the ecosystem.

Multiple Choice

Compare and contrast the roles of producers and consumers in the flow of energy within an ecosystem

• Producers generate energy through photosynthesis, while consumers rely on producers or other organisms for energy.

• Both producers and consumers obtains energy through photosynthesis

• Consumers produce their own food, while producers rely on consuming other organisms for energy.

• Both producers and consumers rely on breaking down oxygen to  produce energy.

Multiple Choice

Compare and contrast how producers and consumers obtain their macromolecules.

• Plants need to make macromolecules for energy production, while consumers obtain macromolecules through photosynthesis.

• Plants need to make macromolecules for DNA replication, while consumers obtain macromolecules through the water cycle.

• Plants need to make macromolecules for protein synthesis, while consumers obtain macromolecules by absorbing nutrients from the soil.

• Plants need to produce their macromolecules, while consumers obtain macromolecules by consuming plants or other organisms.

Producers Also Perform Cellular Respiration

All living things break down food to release energy in cellular respiration

The producer uses the short term energy sugars produced from PS to perform CR
in the mitochondria to make ATP.

All living things break down food through these process using protein enzymes to
convert and use energy to perform cellular functions and maintain homeostasis