Biology Chapter on Energy Molecules and Photosynthesis

Questions and Answers

What is ATP?

High energy molecule that contains energy cells can use (correct)

Energy source from light

Process of producing ATP

Low energy molecule that can be converted to ADP

What is ADP?

Low energy molecule that can be converted to ATP

What is chemosynthesis?

Process by which ATP is synthesized using chemicals as an energy source instead of light

What is photosynthesis?

Process by which light energy is converted to chemical energy, producing sugar and oxygen from carbon dioxide and water Signup and view all the answers

What is chlorophyll?

Light absorbing pigment molecule in photosynthetic organisms Signup and view all the answers

What are thylakoids?

Membrane-enclosed compartments in the grana Signup and view all the answers

What are light dependent reactions?

Part of photosynthesis that absorbs energy from sunlight and transfers it to light independent reactions Signup and view all the answers

What are light independent reactions?

Part of photosynthesis that uses energy absorbed during light dependent reactions to synthesize carbohydrates Signup and view all the answers

What is the Calvin cycle?

Process by which photosynthetic organisms use energy to synthesize simple sugars from CO2 Signup and view all the answers

What is cellular respiration?

Process of producing ATP by breaking down carbon-based molecules when oxygen is present Signup and view all the answers

Aerobic processes require oxygen.

True Signup and view all the answers

Glycolysis is an aerobic process.

False Signup and view all the answers

What happens during glycolysis?

It splits glucose into two three-carbon molecules, producing two molecules of ATP Signup and view all the answers

The chemical equation for photosynthesis is ___.

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

The stages of cellular respiration include _, _, and ___.

Glycolysis, Krebs Cycle, Electron Transport Chain Signup and view all the answers

What is fermentation?

Anaerobic process by which ATP is produced by glycolysis Signup and view all the answers

What is lactic acid?

C3H6O3, it causes muscles to burn during hard exercise Signup and view all the answers

Where does cellular respiration take place?

Mitochondria Signup and view all the answers

What is the importance of fermentation?

It allows glycolysis to continue Signup and view all the answers

What are the differences between light dependent and light independent reactions?

Light dependent reactions capture energy from sunlight, while light independent reactions use that energy. Signup and view all the answers

Study Notes

Energy Molecules

ATP (adenosine triphosphate) is a high-energy molecule providing energy for cellular functions.
ADP (adenosine diphosphate) is a lower-energy molecule that converts to ATP through the addition of a phosphate group.

Photosynthesis

Photosynthesis converts light energy into chemical energy, producing glucose and oxygen from carbon dioxide and water.
Chlorophyll is the pigment responsible for absorbing light in photosynthetic organisms, located in chloroplasts.
Photosynthesis occurs in two stages: light-dependent reactions (capture sunlight) and light-independent reactions (Calvin Cycle uses captured energy).

Chloroplast Structure

Thylakoids are membrane-bound structures within chloroplasts containing chlorophyll for light-dependent reactions.
Grana (stacks of thylakoids) and stroma (fluid surrounding grana) are critical for photosynthesis.

Light Reactions

Light-dependent reactions absorb sunlight, split water molecules, and produce ATP and NADPH for the Calvin Cycle.
Energy captured during these reactions drives carbohydrate synthesis in light-independent reactions.

Cellular Respiration

Cellular respiration produces ATP by breaking down carbon-based molecules (glucose) with oxygen (aerobic process).
Takes place mainly in mitochondria, involving glycolysis, Krebs Cycle, and Electron Transport Chain.

Glycolysis and Fermentation

Glycolysis is the initial step in cellular respiration, converting glucose into two pyruvate molecules and producing two ATP molecules.
Fermentation, an anaerobic process, occurs when oxygen is absent, allowing ATP production to continue in glycolysis and recycling NAD+.

Krebs Cycle

The Krebs Cycle further breaks down carbon molecules after glycolysis, generating electron carriers for the Electron Transport Chain.

Importance of Oxygen

Oxygen acts as the final electron acceptor in cellular respiration, forming water and enabling energy production.

Chemical Equations

Photosynthesis: 6CO2 + 6H2O → C6H12O6 + 6O2
Cellular Respiration: C6H12O6 + 6O2 → 6CO2 + 6H2O

Comparison of Processes

Photosynthesis and cellular respiration are interconnected; photosynthesis captures energy, while cellular respiration releases it, with equations being reverses of each other.
Both glycolysis and Krebs cycle play roles in energy production, with each contributing to ATP synthesis through different pathways.

Role of Fermentation

Fermentation allows glycolysis to continue when oxygen is not available, producing energy in the form of ATP and generating byproducts like lactic acid.

Key Concepts

Light-dependent reactions capture energy from sunlight, while light-independent reactions synthesize sugars.
Cellular respiration has two main stages: aerobic (requires oxygen) and anaerobic (does not require oxygen, e.g., fermentation).
Carbon compounds like carbohydrates, lipids, and proteins are primary energy sources broken down to generate ATP.

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Description

This quiz covers key concepts in biology related to energy molecules such as ATP and ADP, the process of photosynthesis, and the structure of chloroplasts. It explores how light energy is converted into chemical energy and the significance of chlorophyll in this process.