Chapter 4 The Cell in Action

Section 1 – Exchange with the Environment Diffusion – The movement of particles from an area of high concentration to an area of low concentration Osmosis – The diffusion of water through the cell membrane Passive Transport – Diffusion of particles through the proteins from an area of high concentration to an area of low concentration: this requires no energy Active Transport – The movement of particles through proteins against the normal direction of diffusion, from an area of low concentration to an area of high concentration: this requires the cell to use energy Endocytosis – The cell membrane surrounds a particle and encloses it in a vesicle bringing it into the cell Exocytosis – Vesicles are formed at the ER or Golgi Complex and carry the particle to the cell membrane

Section 2 – Cell Energy Vocabulary Photosynthesis – The process by which plants are able to capture light energy from the sun and change it into food Cellular Respiration – The process of producing ATP in the cell from oxygen and glucose; releases carbon dioxide and water Fermentation – The breakdown of sugars to make ATP in the absence of oxygen

Photosynthesis Light energy, carbon dioxide and water are used to make glucose (food) in chloroplasts. Oxygen in released

Cellular Respiration Oxygen and the energy in glucose are used to make ATP. ATP is a molecule that stores energy in a form that cells can use. ATP is produced by the mitochondria. Carbon dioxide and water are also released. Cellular respiration occurs in both plant and animal cells.

Section 3 – The Cell Cycle Cell Cycle – Life cycle of the cell Chromosome – Structures where the DNA of a cell is organized Binary Fission – Cell division in bacteria: each cell contains one copy of the DNA Homologous Chromosomes – Chromosomes with matching information Chromatids – The copies made after each chromosome is duplicated Centromere – The region where the chromatids are held together Mitosis – The complicated process of chromosome separation Cytokinesis – The process of the cytoplasm splitting in two

Bacteria (Prokaryotic) reproduce by the process of Binary Fission Eukaryotic Cells reproduce by the process of mitosis Eukaryotic cells that have a cell wall (plants, fungi, algae) use mitosis but a cell plate forms in the middle separating the two new cells