Biology Test 4: Photosynthesis Reactants and Products

Study Notes

Photosynthesis Overview

Reactants: Sunlight, carbon dioxide, and water.
Products: Glucose and oxygen.
Reactants contributing to glucose: Carbon dioxide, water, and light energy.

Photosynthesis Chemical Processes

Carbon dioxide is reduced during photosynthesis.
Photosynthesis occurs in two stages:
- Light-Dependent Reactions: Located in thylakoid membranes; utilize light energy to produce ATP and NADPH.
- Calvin Cycle: Occurs in stroma; converts CO2 and water into organic molecules like glucose.

Light and Pigments

Chlorophyll reflects/transmits green light, which is least effective for photosynthesis.
End product of Calvin Cycle: G3P (glyceraldehyde-3-phosphate).
Seasonal color changes in leaves occur due to chlorophyll degradation and the presence of carotenoids.

Photosystem Outputs

Photosystem I produces NADPH.

Cellular Energy Dynamics

Photosynthesis produces food using energy; cellular respiration breaks down food to release energy; they are interconnected via chemiosmosis.

DNA Structure and Function

Eukaryotic chromosomes are made of DNA and histone proteins.
Nucleotides are joined together by phosphodiester bonds; complementary bases are connected by hydrogen bonds.
DNA structure: Double helix, with antiparallel strands.

Telomeres

Protective structures at chromosome ends, preventing damage and fusion with other chromosomes.

DNA Replication

DNA synthesis occurs in a 5' to 3' direction, adding nucleotides at the 3' end.
Prokaryotic replication has one origin and occurs in cytoplasm, while eukaryotic replication has multiple origins and occurs within the nucleus.

Key Enzymes in DNA Replication

Helicase: Separates parent strands.
Single-strand binding proteins: Prevent secondary structures from forming.
Topoisomerase: Prevents overwinding of the double helix.
Primase: Assembles RNA primer on the template.
DNA Polymerase (I and III): Adds nucleotides and fills gaps.
DNA Ligase: Stabilizes two DNA strands post-separation.

Leading vs. Lagging Strand Synthesis

Leading strand: Synthesized continuously.
Lagging strand: Synthesized in segments due to discontinuity.

Cell Cycle and Mitosis

Interphase: DNA is copied.
Prophase: Chromatin condenses, centrosomes move, nucleoli break down.
Prometaphase: Nuclear membrane disintegrates.
Metaphase: Chromosomes align at the center; microtubules attach to kinetochores.
Anaphase: Sister chromatids move apart toward opposite ends.
Telophase: Nuclear membranes reform around chromosomes, cell begins to split.

Cytokinesis

Divides the cell post-mitosis; failure to undergo cytokinesis leads to multinucleated cells.
Animal cells use cleavage furrows, while plant cells form cell plates which develop into cell walls.

Cell Cycle Checkpoints

Key checkpoints: G1, S phase, G2, and M phase.
M phase checkpoint ensures proper attachment of chromosomes to spindle fibers.
Loss of checkpoint regulation can lead to cancerous cell growth.

Description

This quiz focuses on the essential reactants and products of photosynthesis, a key biological process. Players will understand what contributes to this vital function in plants, including the role of sunlight, carbon dioxide, and water. Test your knowledge on these important concepts related to plant biology.

Biology Test 4: Photosynthesis Reactants and Products

Choose a study mode

Podcast

Questions and Answers

What are the reactants (input) of photosynthesis?

What reactants contribute to the sugar produced in photosynthesis?

Is CO2 oxidized or reduced in photosynthesis?

What are the two stages of photosynthesis?

What light does chlorophyll reflect/transmit?

What is produced at the end of photosystem I?

What is the difference in the purpose of photosynthesis versus cellular respiration?

What are the 2 macromolecules that make up eukaryotic chromosomes?

What type of chemical bond joins nucleotides together in a nucleic acid?

Describe the structure of DNA.

What are telomeres?

What is the direction of synthesis of a new DNA strand during replication?

How is DNA replication in prokaryotes different from in eukaryotes?

What happens during cytokinesis?

At what stage of the cell cycle does DNA replication occur?

What is the importance of the M phase checkpoint?