Chapter 4 Preview Section 1 Exchange with the Environment The Cell in Action Preview Section 1 Exchange with the Environment Section 2 Cell Energy Section 3 The Cell Cycle Concept Mapping

Section 1 Exchange with the Environment Chapter 4 Bellringer Which of the following best describes a living cell: a) building block b) a living organism c) a complex factory d) all of the above Write a paragraph in your science journal defending your choice.

Chapter 4 Objectives Explain the process of diffusion. Section 1 Exchange with the Environment Chapter 4 Objectives Explain the process of diffusion. Describe how osmosis occurs. Compare passive transport with active transport. Explain how large particles get into and out of cells.

Chapter 4 What Is Diffusion? Section 1 Exchange with the Environment Chapter 4 What Is Diffusion? Diffusion is the movement of particles from regions of higher concentration to regions of lower concentration. Does Not Require Energy Diffusion of Water The diffusion of water through cell membranes is called osmosis.

What Is Diffusion?, continued Section 1 Exchange with the Environment Chapter 4 What Is Diffusion?, continued The Cell and Osmosis Osmosis is important to cell functions. Semipermeable membrane- only some substances can pass through Plasma surrounds red blood cells and is made up of water, salts, sugars, and other particles. Osmosis keeps the concentration of these particles in balance. When a wilted plant is watered, osmosis makes the plant firm again.

Moving Small Particles Section 1 Exchange with the Environment Chapter 4 Moving Small Particles Active Transport A process of transporting particles that requires the cell to use energy is called active transport. (Low to High Concentration) require energy Passive Transport The movement of particles across a cell membrane without the use of energy by the cell is called passive transport. (High to Low Concentration) does not require energy

Section 1 Exchange with the Environment Chapter 4

Diffusion and Osmosis Channels: Passageways in the cell membrane that allow particles through.

Moving Large Particles Section 1 Exchange with the Environment Chapter 4 Moving Large Particles Endocytosis The active-transport process by which a cell surrounds a large particle and encloses the particle in a vesicle to bring the particle into the cell is called endocytosis. Exocytosis The process in which a cell releases a particle by enclosing the particle in a vesicle that then moves to the cell surface and fuses with the cell membrane is called exocytosis. Both require energy therefore are considered active transport.

Moving Large Particles Section 1 Exchange with the Environment Chapter 4 Moving Large Particles Vesicle- a sac that forms from pieces of the cell membrane. Carry the particles

Section 1 Exchange with the Environment Chapter 4

Section 2 Cell Energy Chapter 4 Bellringer Make a list of all the different types of cells that you can think of and the jobs they do. Then make a list of all the reasons that a cell needs energy. Write your answers in your science journal.

Chapter 4 Objectives Describe photosynthesis and cellular respiration. Section 2 Cell Energy Chapter 4 Objectives Describe photosynthesis and cellular respiration. Compare cellular respiration with fermentation.

Chapter 4 From Sun to Cell Section 2 Cell Energy Chapter 4 From Sun to Cell Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to make food. Chlorophyll Plant cells have molecules that absorb light energy. These molecules are called pigments. Chlorophyll, the main pigment used in photosynthesis, gives plants their green color.

From Sun to Cell, continued Section 2 Cell Energy Chapter 4 From Sun to Cell, continued

Getting Energy from Food Section 2 Cell Energy Chapter 4 Getting Energy from Food Cellular Respiration During cellular respiration, food (such as glucose) is broken down into carbon dioxide and water, and energy is released.

Getting Energy from Food, continued Section 2 Cell Energy Chapter 4 Getting Energy from Food, continued Connection Between Photosynthesis and Respiration During photosynthesis, cells take in carbon dioxide and release oxygen. During cellular respiration, cells use oxygen to break down glucose and release energy and carbon dioxide. Fermentation When muscles can’t get the oxygen for cellular respiration, they use fermentation to get energy. Fermentation is the breakdown of food without the use of oxygen.

Section 2 Cell Energy Chapter 4

Chapter 4 Section 3 The Cell Cycle Bellringer Biology is the only science in which multiplication means the same thing as division—at least with regards to cells. Explain what is meant by this statement in your science journal.

Chapter 4 Objectives Explain how cells produce more cells. Section 3 The Cell Cycle Objectives Explain how cells produce more cells. Describe the process of mitosis. Explain how cell division differs in animals and plants.

Chapter 4 The Life of a Cell Section 3 The Cell Cycle The Life of a Cell The cell cycle begins when the cell is formed and ends when the cell divides and forms new cells. Before a cell divides, it must make a copy of its DNA which is organized into structures called chromosomes.

The Life of a Cell, continued Chapter 4 Section 3 The Cell Cycle The Life of a Cell, continued Making More Prokaryotic Cells Cell division in bacteria is called binary fission, which means “splitting into two parts.” Bacteria have a single circular DNA molecule (chromosome). Binary fission results in two cells that each contain one copy of the circle of DNA.

The Life of a Cell, continued Chapter 4 Section 3 The Cell Cycle The Life of a Cell, continued Eukaryotic Cells and Their DNA The chromosomes of eukaryotic cells contain more DNA than those of prokaryotic cells. In a eukaryotic cell, chromosomes are found in the nucleus and are made of DNA and protein. Pairs of similar chromosomes are called homologous chromosomes. Copyright © by Holt, Rinehart and Winston. All rights reserved.

The Life of a Cell, continued Chapter 4 Section 3 The Cell Cycle The Life of a Cell, continued Making More Eukaryotic Cells The cell cycle has three stages: Interphase: The cell grows and copies its chromosomes. Mitosis: The chromatids separate. Cytokinesis: The cell splits into two identical cells.

Mitosis and the Cell Cycle Chapter 4 Section 3 The Cell Cycle Mitosis and the Cell Cycle Mitosis has four phases: Prophase – chromosomes condense and form chromosomes Metaphase – Chromatids line up in the middle of the cell Anaphase – Chromatids move towards opposite ends of the cell Telophase – New nuclear membrane forms

Chapter 4 Mitosis Section 3 The Cell Cycle Click below to watch the Visual Concept. Visual Concept

Mitosis and the Cell Cycle, continued Chapter 4 Section 3 The Cell Cycle Mitosis and the Cell Cycle, continued Cytokinesis is the division of cytoplasm. In animal cells and other eukaryotes that do not have cell walls, division of the cytoplasm begins at the cell membrane. In plant cells and in other eukaryotes with cell walls, a cell plate forms and the cell splits into two cells.

Section 3 The Cell Cycle Chapter 4

Chapter 4 Concept Mapping The Cell in Action Concept Mapping Use the terms below to complete the concept map on the next slide. ATP photosynthesis oxygen water consumers lactic acid producers respiration energy

Chapter 4 The Cell in Action

Chapter 4 The Cell in Action