Biology Chapter 7 Study Guide

Study Notes

Autotrophs and Heterotrophs

Autotrophs produce complex organic compounds using simple substances, energy is derived from light (photosynthesis) or inorganic reactions (chemosynthesis).
Heterotrophs cannot fix carbon and rely on organic carbon for growth.

Producers and Photoautotrophs

Producers include green plants and various microorganisms that convert light or chemical energy into organic matter.
Photoautotrophs, such as plants, use sunlight to transform inorganic materials into organic compounds for cellular functions.

Structure and Function of Chloroplasts

Chloroplasts are mainly found in the mesophyll cells of leaves, where they are essential for photosynthesis.
Thylakoid membranes within chloroplasts are the sites where light energy is converted to chemical energy.

Oxygen Production in Photosynthesis

Isotope tracing revealed that the source of oxygen produced during photosynthesis is water (H2O).

Light Reactions of Photosynthesis

Light-dependent reactions require water (H2O), ADP, and NADP+ as reactants, producing oxygen, ATP, and NADPH.
Light-independent reactions (Calvin Cycle) utilize ATP, NADPH, and carbon dioxide to produce glucose.

Photosystem Functionality

Chlorophyll captures sunlight, facilitating the conversion of light energy into chemical energy through a series of electron transfer reactions.
The process leads to the splitting of water molecules, resulting in oxygen as a byproduct.

ATP Generation in Light Reactions

ATP and NADPH are generated through electron transport chains and chemiosmosis, which create a proton gradient that drives ATP synthesis.

Calvin Cycle Overview

The Calvin Cycle operates in the chloroplast stroma, fixing carbon dioxide into glucose.
The cycle requires ATP and NADPH produced by light reactions, converting CO2 into G3P and regenerating RuBP for continuous operation.

Carbon Fixation Mechanisms

C3 plants directly fix carbon dioxide using the Calvin Cycle.
C4 plants utilize a modified pathway to efficiently capture carbon at higher temperatures and light intensities.
CAM plants fix carbon during the night to minimize water loss; examples include cacti and succulents.

Greenhouse Effect and Climate Change

The greenhouse effect is a natural phenomenon that warms the Earth by trapping infrared radiation from the sun.
Increased greenhouse gas emissions from human activities strengthen this effect, leading to global warming, impacting plant growth and ecosystems.

Description

Dive into the essential concepts of Chapter 7 in Biology with this study guide. Explore key terms like autotrophs, heterotrophs, and producers, along with their definitions and roles in the ecosystem. Perfect for preparing for exams and enhancing your understanding of biological classification.