1.5 Lesson 1 Unit C Summary
In this lesson, you explored the following essential question:
- What pathways do energy and matter follow in living organisms?
Photosynthesis and cellular respiration are metabolic pathways. 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. You will learn about these specific processes in the next lesson.
Lesson Glossary
active transport: a process that requires energy from ATP to move substances against the concentration gradient (low to high)
ATP (adenosine triphosphate): a high-energy phosphate molecule that provides and stores the energy required for cellular functions
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 release
osmosis: the diffusion of water across a semipermeable membrane
oxidation: a loss of electrons
passive transport: no energy is required by the cell to move particles
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 atom which has lost an electron
redox reaction: a reaction involving the transfer of electrons
reduction: a gain of electrons