Biology Chapter Photosynthesis

Questions and Answers

What connects the two photosystems in the light reactions?

An electron transport chain

In which organelles does photosynthesis take place?

Chloroplasts

In the absence of oxygen, cells need a way to regenerate which compound?

NAD+

In muscle cells, fermentation produces _____?

Lactate and NAD+ Signup and view all the answers

Which equation represents photosynthesis?

6CO2 + 6H2O → C6H12O6 + 6O2 Signup and view all the answers

What two molecules are produced by the light reactions and used to power the Calvin cycle?

ATP and NADPH Signup and view all the answers

What provides electrons for the light reactions?

Water Signup and view all the answers

What transports electrons from the light reactions to the Calvin cycle?

NADPH Signup and view all the answers

The light reactions take place in the _ and the Calvin cycle takes place in the _.

thylakoids; stroma Signup and view all the answers

What provides the carbon atoms that are incorporated into sugar molecules in the Calvin cycle?

Carbon dioxide Signup and view all the answers

_____ releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment.

Electron transport chain Signup and view all the answers

_____ splits water into 1/2 O2, H+, and e-.

Photosystem II Signup and view all the answers

Energized electrons from ____ enter an electron transport chain and are then used to reduce NADP+.

Photosystem I Signup and view all the answers

What is the name given to organisms that can make their own food and thus sustain themselves without consuming organic molecules derived from other organisms?

Autotrophs Signup and view all the answers

Thylakoids are arranged in stacks called?

Grana Signup and view all the answers

Which of the following are produced during the light reactions of photosynthesis? (Select all that apply)

ATP Signup and view all the answers

Which statement regarding the light reactions is true?

Electrons are supplied to chlorophyll P680 as it reduces the primary electron acceptor. Signup and view all the answers

Photosystem II?

passes electrons to photosystem I. Signup and view all the answers

As a result of the cascade of electrons moving down the electron transport chain and leaving the light reactions?

NADP+ is reduced to NADPH. Signup and view all the answers

Where do the electrons needed by photosystem II originate?

Water Signup and view all the answers

Photosynthetic organisms derive their carbon from?

Carbon dioxide Signup and view all the answers

In the Calvin cycle carbon dioxide provides ___, whereas ATP and NADPH provide _ and ___, respectively.

carbon...energy...high-energy electrons Signup and view all the answers

Carbon fixation involves the addition of carbon dioxide to _____?

RuBP Signup and view all the answers

After 3-PGA is phosphorylated, it receives energized electrons from _____?

NADPH Signup and view all the answers

How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose?

Six Signup and view all the answers

In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules?

3 Signup and view all the answers

In simple summary form, the input of the Calvin cycle for every product is , and the output is used for glucose synthesis.

3 CO2...; a three-carbon molecule Signup and view all the answers

In C3 plants, the conservation of water promotes _____?

Photorespiration Signup and view all the answers

In C4 and CAM plants, carbon dioxide is fixed in the _____ of mesophyll cells.

Cytoplasm Signup and view all the answers

C4 plants differ from C3 and CAM plants in that C4 plants _____?

transfer fixed carbon dioxide to cells in which the Calvin cycle occurs Signup and view all the answers

Which of the following statements about the greenhouse effect is true?

True Signup and view all the answers

Asexual and sexual reproduction differ in that sexual reproduction _____?

True Signup and view all the answers

Bacteria divide by:

Binary fission Signup and view all the answers

The first step of bacterial replication is _____?

DNA replication Signup and view all the answers

What differs concerning the DNA in bacterial cells as opposed to eukaryotic cells?

The amount of DNA present, whether the DNA is housed in a nucleus or not, whether the DNA is linear or circular Signup and view all the answers

Prior to mitosis and after S phase, each chromosome of a eukaryotic cell consists of a pair of identical structures called?

Sister chromatids Signup and view all the answers

During _____ both the contents of the nucleus and the cytoplasm are divided.

The mitotic phase Signup and view all the answers

During _____ the cell grows and replicates both its organelles and its chromosomes.

Interphase Signup and view all the answers

Study Notes

Photosynthesis and Light Reactions

Light reactions are connected by an electron transport chain which facilitates the flow of electrons.
Photosynthesis occurs in chloroplasts, converting carbon dioxide and water into glucose and oxygen using light energy.
NAD+ is essential for cellular respiration in anaerobic conditions, allowing cells to regenerate energy carriers.
Muscle cells undergo fermentation, producing lactate and restoring NAD+.
Photosynthesis is summarized by the equation: 6CO2 + 6H2O → C6H12O6 + 6O2.
ATP and NADPH, produced in light reactions, provide energy and reducing power for the Calvin cycle.
Water molecules are a source of electrons in the light reactions, essential for sustaining the process.

Calvin Cycle and Carbon Fixation

The Calvin cycle uses carbon dioxide for carbon buildup in sugars, requiring ATP and NADPH as energy sources.
Photosystem II splits water into oxygen, protons, and electrons, initiating electron transport.
Grana are stacks of thylakoids where light reactions take place; the Calvin cycle occurs in the stroma.
The ultimate energy source for photosynthesis is sunlight, driving the carbon fixation process.
For each glucose molecule produced, six carbon dioxide molecules must be added to RuBP.

Photosynthetic Variations

C3 plants face challenges like photorespiration in water-scarce environments, causing reduced efficiency.
C4 and CAM plants have adaptations that allow them to fix carbon dioxide in different cellular environments, enhancing water use and efficiency.
C4 plants separate carbon fixation and the Calvin cycle in different cells, improving their photosynthetic efficiency.

Bacterial Division

Bacteria reproduce primarily by binary fission, a simple yet effective method of cell division.
DNA replication is the critical first step in bacterial replication, ensuring genetic material is fully copied before division.
Unlike eukaryotic cells, bacterial DNA is typically circular and not enclosed in a nucleus.

Mitosis and Cell Cycle

Eukaryotic chromosomes consist of two identical sister chromatids post-DNA replication, which ensures genetic consistency during cell division.
The mitotic phase includes both mitosis and cytokinesis, encompassing the entire process of cell division.
The interphase is characterized by cell growth and preparation for division, replicating organelles and chromosomes.

Key Terms

Autotrophs are organisms capable of producing their own food through photosynthesis.
NADPH functions as an electron carrier from light reactions to the Calvin cycle, enabling sugar synthesis.
RuBP is a crucial molecule in the Calvin cycle where carbon dioxide fixation occurs.

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Description

Test your knowledge on the light reactions of photosynthesis with this quiz. Explore how the photosystems interact and where these processes occur. Challenge your understanding of the functions of chloroplasts and the role of electron transport chains.