Module 5 Intro

1. Module 5 Intro

1.8. Page 6

Lesson 1

Module 5—Photosynthesis and Cellular Respiration

Lesson Summary

 

In this lesson you explored the following essential question:

  • What pathways do energy and matter follow in living organisms?

Energy and matter follow many pathways. Matter is transported in many different ways. Osmosis and active transport are two ways that you explored—both are involved in photosynthesis and cellular respiration.

 

The most important metabolic pathways for plants are photosynthesis and cellular respiration. Cellular respiration is the most important metabolic pathway for humans. These pathways break down or synthesize carbon dioxide, water, carbohydrates, oxygen, and ATP (energy). The creation or breakdown of these important molecules is reliant on oxidation-reduction reactions. These reactions occur via electron transport systems and chemiosmosis in the mitochondrion and chloroplast.

 

Lesson Glossary

 

active transport: a process that requires energy from ATP to move substances against the concentration gradient

 

ATP (adenosine triphosphate): a high-energy phosphate molecule that provides and stores the energy required for cellular functions

 

chemiosmosis: the process by which ATP is generated through the movement of protons down a concentration gradient

 

The protons move across the inner membranes to the mitochondrion and thylakoid membrane of the chloroplast and combine with ADP and phosphate molecules to form ATP.

 

diffusion: a process in which molecules move from areas of high concentration to low concentration

 

endocytosis: a process in which cell membranes engulf a substance and pinch off inside the cell

 

exocytosis: a process in which a vacuole containing substances from inside a cell (cytoplasm) fuses with the cell wall and the contents are released outside of the cell

 

facilitated diffusion: a process in which larger molecules need the help of proteins in cell walls to move from areas of high concentration to low concentration

 

metabolism: all of the chemical reactions that occur within a cell to support and sustain its life functions

 

This can be the synthesis of molecules or the breaking down of molecules for energy.

 

osmosis: the diffusion of water across a semipermeable membrane

 

oxidation: a loss of electrons

 

passive transport: no energy required

 

phagocytosis: a process in which the cell wall engulfs a large particle, such as bacteria or a blood cell, and pinches off inside of the cell

 

pinocytosis: the cell wall engulfs liquids and their solutes and pinches off inside the cell

 

proton: a hydrogen ion containing one electron

 

redox reaction: a reaction involving the transfer of electrons

 

reduction: a gain of electrons