* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter 3, Section 1
Survey
Document related concepts
Biochemical switches in the cell cycle wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Cell nucleus wikipedia , lookup
Cell encapsulation wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cellular differentiation wikipedia , lookup
Signal transduction wikipedia , lookup
Cell culture wikipedia , lookup
Programmed cell death wikipedia , lookup
Cell membrane wikipedia , lookup
Cell growth wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cytokinesis wikipedia , lookup
Transcript
3.1 Cell Theory KEY CONCEPT Cells are the Basic unit of life. 3.1 Cell Theory The cell theory grew out of the work of many scientists and improvements in the microscope. • Many scientists contributed to the cell theory. 3.1 Cell Theory The cell theory grew out of the work of many scientists and improvements in the microscope. • Many scientists contributed to the cell theory. • More was learned about cells as microscopes improved. • The cell theory is a unifying concept of biology. 3.1 Cell Theory Early studies led to the development of the cell theory. • The Cell theory has three principles. – All organisms are made of cells. – All existing cells are produced by other living cells. – The cell is the most basic unit of life. 3.1 Cell Theory Prokaryotic cells lack a nucleus and most internal structures of eukaryotic cells. • All cells share certain characteristics. – Cells tend to be microscopic. – All cells are enclosed cell membrane by a membrane. – All cells are filled with cytoplasm. cytoplasm Bacterium (colored SEM; magnification 8800x) 3.1 Cell Theory There are two cell types: eukaryotic cells and prokaryotic cells. • Eukaryotic cells have a nucleus. nucleus • Prokaryotic cells do not have membranebound organelles. organelles cell membrane 3.1 Cell Theory There are two cell types: eukaryotic cells and prokaryotic cells. • Prokaryotic cells do not have a nucleus. nucleus • Prokaryotic cells do not have membrane-bound organelles. organelles cell membrane cytoplasm 3.1 Cell Theory KEY CONCEPT Eukaryotic cells share many similarities. 3.1 Cell Theory Cells have an internal structure. • The cytoskeleton has many functions. – supports and shapes cell – helps position and transport organelles – provides strength – assists in cell division – aids in cell movement 3.1 Cell Theory Several organelles are involved in making and processing proteins. • The nucleus stores genetic information. 3.1 Cell Theory Several organelles are involved in making and processing proteins. • The nucleus stores genetic information. • Many processes occur in the endoplasmic reticulum. 3.1 Cell Theory Several organelles are involved in making and processing proteins. • The nucleus stores genetic information. • Many processes occur in the endoplasmic reticulum. • There are two types of endoplasmic reticulum. 3.1 Cell Theory Several organelles are involved in making and processing proteins. • The nucleus stores genetic information. • Many processes occur in the endoplasmic reticulum. • There are two types of endoplasmic reticulum. – rough endoplasmic reticulum 3.1 Cell Theory Several organelles are involved in making and processing proteins. • The nucleus stores genetic information. • Many processes occur in the endoplasmic reticulum. • There are two types of endoplasmic reticulum. – rough endoplasmic reticulum – smooth endoplasmic reticulum 3.1 Cell Theory Several organelles are involved in making and processing proteins. (continued) • Ribosomes link amino acids to form proteins. 3.1 Cell Theory Several organelles are involved in making and processing proteins. (continued) • Ribosomes link amino acids to form proteins. • Vesicles are membrane-bound sacs that hold materials. 3.1 Cell Theory Golgi apparatus – packages and delivers proteins 3.1 Cell Theory Other organelles have various functions. • Mitochondria supply energy to the cell. 3.1 Cell Theory Other organelles have various functions. • Mitochondria supply energy to the cell. • Vacuoles are fluid-filled sacs that hold materials. 3.1 Cell Theory Other organelles have various functions. • Mitochondria supply energy to the cell. • Vacuoles are fluid-filled sacs that hold materials. • Lysosomes contain enzymes to digest material. 3.1 Cell Theory Other organelles have various functions. • Mitochondria supply energy to the cell. • Vacuoles are fluid-filled sacs that hold materials. • Lysosomes contain enzymes to digest material. • Centrioles are tubes found in the – Centrioles help divide DNA during mitosis 3.1 Cell Theory Plant cells have cell walls and chloroplasts. • A cell wall provides rigid support. 3.1 Cell Theory Plant cells have cell walls and chloroplasts. • A cell wall provides rigid support. • Chloroplasts convert solar energy to chemical energy. 3.1 Cell Theory KEY CONCEPT The cell membrane is a barrier that separates a cell from the external environment. 3.1 Cell Theory Cell membranes are composed of two phospholipid layers. • The cell membrane has two major functions. – forms a boundary between inside and outside of the cell – controls passage of materials cell membrane inside cell outside cell 3.1 Cell Theory Cell membranes are composed of two phospholipid layers. • The cell membrane is made of a phospholipid bilayer. • There are other molecules embedded in the membrane. • The fluid mosaic model describes the membrane. cell membrane carbohydrate chain cholesterol protein protein channel protein 3.1 Cell Theory Cell membranes are composed of two phospholipid layers. • The cell membrane is selectively permeable. Some molecules can cross the membrane while others cannot. 3.1 Cell Theory Cell membranes are composed of two phospholipid layers. • The cell membrane is selectively permeable. Some molecules can cross the membrane while others cannot. 3.1 Cell Theory What Goes in? Small, nonpolar molecules pass through lipid layers Small polar molecules go through proteins Large molecules moved in vesicles 3.1 Cell Theory Chemical signals are transmitted across the cell membrane. • Receptors bind with ligands and change shape. • There are two types of receptors. – intracellular receptor 3.1 Cell Theory Chemical signals are transmitted across the cell membrane. • Receptors bind with ligands and change shape. • There are two types of receptors. – intracellular receptor – membrane receptor