Cellular Structure and Function Chapter 7 Section 1

Cellular Structure and Function Chapter 7 Section 1: Section 2: Section 3: Section 4: Cell Discovery and Theory The Plasma Membrane Structures and Organelles Cellular Transport

Section 1: Cell Discovery and Theory

Section 1: Cell Discovery and Theory The invention of the microscope led to the discovery of cells. K What I Know W What I Want to Find Out L What I Learned

History of the Cell Theory • A _______is the basic structural and functional unit of all living organisms. • Cells are so small that their existence was unknown before the invention of ____________. Cell Discovery and Theory

History of the Cell Theory The cell theory • The ______theory is one of the fundamental ideas of modern biology, and includes the following three principles: • All living organisms are composed of ______or more cells. • Cells are the basic unit of structure and organization of all _____ organisms. • Cells arise only from previously existing cells, with cells passing copies of their genetic material on to their daughter cells. Cell Discovery and Theory

Discovery of Cells • Cells are about 1/500 th the size of a. • In 1665 Robert Hooke used a 3 -lens compound microscope to examine thin slices of _____. • He observed that cork is made of tiny, hollow compartments. • He gave them the name “______” • Hooke was only looking at cell walls & empty space.

Microscope Technology Compound ________microscopes • Use a series of glass lenses and visible light to magnify images • Magnify images up to ~______× actual size _________microscopes • Create an image by illuminating a sample with a beam of electrons and collecting the electrons that are reflected back from the sample • Magnify images up to _______× actual size Cell Discovery and Theory

Basic Cell Types • All cells have at least one physical trait in common: a plasma membrane. • A ______membrane is a special boundary that helps control what enters and leaves the cell. • Most cells contain _______material in some form. • Most cells break down molecules to generate ________. • There are two basic kinds of cells: eukaryotic and prokaryotic. Cell Discovery and Theory

_______ CORK The first to ______ cells. Responsible for NAMING them ______ LEEUWENHOEK _______ ANIMALCULES Made better LENSES _______ and observed cells in greater _______. First to observe NUCLEUS _______ SCHLEIDEN _______ SCHWANN _______ VIRCHOW _______ RESPONSIBLE FOR CELL THEORY The first to note that _______ PLANTS were made up of ______ Concluded that all ___________ were made up of CELLS ______ Proposed that all cells come from ______

Basic Cell Types • __________cells contain a nucleus and other organelles. • _____are specialized structures that perform specific cell functions. • The ______is the distinct central organelle that contains the cell’s genetic material. • Eukaryotic cells are generally much larger than prokaryotic cells. Cell Discovery and Theory

Basic Cell Types • _______cells are cells without a nucleus or other membrane-bound organelles. • Smaller and simpler than eukaryotes • Probably similar to first organisms that lived on earth Cell Discovery and Theory

Basic Cell Types Origin of cell diversity • Eukaryotic cells may have evolved from prokaryotic cells. • The endosymbiont theory proposes that a symbiotic relationship formed between two prokaryotic cells, one of which lived inside the other. • Eventually the symbiotic relationship led to the two cells becoming one. • Because eukaryotic cells are larger and more complex, they developed specific functions. • These specific functions led to cell diversity, and thus organismal diversity. Cell Discovery and Theory

Eukaryotes VS. Prokaryotes

Essential Questions • How are the advances in microscope technology related to discoveries about cells? • What are the similarities and differences between compound light microscopes and electron microscopes? • What are the principles of the cell theory? • What are the differences between a prokaryotic cell and a eukaryotic cell? Cell Discovery and Theory

Section 2: The Plasma Membrane

Section 2: The Plasma Membrane The plasma membrane helps to maintain a cell’s homeostasis. K What I Know W What I Want to Find Out L What I Learned

Function of the Plasma Membrane • The process of maintaining balance in an organism’s internal environment is called ______________. • One of the structures responsible for homeostasis is the _____membrane. • The plasma membrane forms a thin, flexible boundary between a cell and its environment. The Plasma Membrane

Function of the Plasma Membrane • Plasma membranes have selective ______, meaning they allow some substances to pass through while keeping others out. • Control of how, when, and how much of various substances enter and leave a cell depends on the structure of the plasma membrane. The Plasma Membrane

Structure of the Plasma Membrane The phospholipid bilayer • The plasma membrane is composed of _________– two layers of phospholipids are arranged to allow the membrane to exist in a watery environment. • The phospholipid bilayer has polar heads facing outside and nonpolar tails facing inside the cell, allowing the membrane to keep the internal and external environments separate. The Plasma Membrane

Phospholipids

Structure of the Plasma Membrane Other components of the plasma membrane • The plasma membrane also contains cholesterol, _______, and carbohydrates. • Some proteins called receptors transmit signals to the inside of the cell. • Some proteins serve as support structures for the membrane. • __________move needed substances and wastes through the membrane. The Plasma Membrane

Structure of the Plasma Membrane Other components of the plasma membrane • Cholesterol prevents the fatty acid tails of the phospholipid bilayer from _________together. • Cholesterol contributes to the ________of the membrane. The Plasma Membrane

Structure of the Plasma Membrane Other components of the plasma membrane • Carbohydrates define the cell’s ____________ • Help cells identify chemical signals The Plasma Membrane

Structure of the Plasma Membrane Other components of the plasma membrane • The ________describes the phospholipids in the bilayer as a “sea” in which other components can float and move around. • The different substances in the plasma membrane create a pattern or mosaic on the surface of the cell. The Plasma Membrane

Fluid Mosaic Model

Essential Questions • How does a cell’s plasma membrane function? • What are the roles of proteins, carbohydrates, and cholesterol in the plasma membrane? The Plasma Membrane

Section 3: Structures and Organelles

Section 3: Structures and Organelles Eukaryotic cells contain organelles that allow the specializations and the separation of functions within the cell. K What I Know W What I Want to Find Out L What I Learned

Cytoplasm and Cytoskeleton • The environment enclosed by the plasma membrane is a semifluid material called ________________. • In prokaryotes, all the chemical processes of the cell take place directly in the cytoplasm. • In eukaryotes, these processes take place within organelles in the cytoplasm. Structures and Organelles

The clear, jellylike material between the cell membrane and _________________________ the nucleus that makes up most of the cell ___________________ (Most of all cell activity occurs here. ) ______________________

Cytoplasm and Cytoskeleton • The ____is a supporting network of long, thin protein fibers that form a framework for the cell and proved an anchor for the organelles. • Microtubules are long, hollow protein cylinders that form a rigid skeleton for the cell and assist in moving substances within the cell. • Microfilaments are thin protein threads that help give the cell shape and enable the part or the entire cell move. Structures and Organelles

Cell Structures The nucleus • • Contains most of the cell’s ______, which stores information used to make proteins that determine a cell’s growth, function, and reproduction Is surrounded by a double membrane called a nuclear ________ Structures and Organelles

The control center of the cell. __________________________ Parts of the Nucleus: _________________________ Nuclear Membrane: The membrane that surrounds the nucleus. _________________ Nuclear Pores: allow_________________ some particles to move in and out of the nucleus __________________________________

Cell Structures Ribosomes • ___________are organelles that manufacture proteins. – Not membrane-bound like other organelles – Produced inside the nucleus in the nucleolus Structures and Organelles

MAKES ______ FOR THE BODY. ___________________ FOUND ON ENDOPLASMICE RETICULUM AND THROUGHOUT ______________________________ CYTOPLASM _________________

Cell Structures Endoplasmic reticulum • The __________(ER) is a membrane system of folded sacs and interconnected channels that serves as the site for protein and lipid synthesis. – Two types: rough and smooth Structures and Organelles

_____________________________ Moves cell materials from cell membrane to nuclear membrane and ________________ visa versa. ______________________ (Can usually find ribosomes on this network. ) _______________

Cell Structures Golgi apparatus • • The ________is a flattened stack of membranes that modifies, sorts, and packages proteins. Proteins are packaged into sacs called vesicles, which can fuse to the plasma membrane and release the proteins to the environment. Structures and Organelles

_________ materials for the cell. ____________________

Cell Structures Vacuoles • • • A _______is a membrane bound sac used for temporary storage. Vacuoles store food, enzymes, or waste. Vacuoles are only found in plant cells. Structures and Organelles

Stores _________for cell ____________________ ANIMAL CELL PLANT CELL Contains many small vacuoles ________________________________ Contains one large “central vacuole ________________ that takes up most of the space ____________ inside of a plant cell ____

Cell Structures Lysosomes • • _____are vesicles that contain substances that digest excess or wornout organelles and food particles. They also digest bacteria or viruses that invade the cell. Structures and Organelles

Helps digest, (break down), _____materials of cell. _________________________ ______

Cell Structures Centrioles • • _____are organelles made of microtubules that function during cell division. They are located in the cytoplasm. Structures and Organelles

Parts of an ANIMAL cell that help with cell ______________________________

Cell Structures Mitochondria • • ________convert fuel particles into usable energy. They have an outer membrane and a highly folded inner membrane that provides surface area for breaking the bonds in sugar molecules. Structures and Organelles

Responsible for supplying ______to the cell. _____________________________________

Cell Structures Chloroplasts • • Plant cells and some other eukaryotes contain ______, which capture light and convert it into chemical energy in process called photosynthesis. They are composed of multiple small disks called thylakoids, which contain the light capturing pigment chlorophyll. Structures and Organelles

_________________________ The plant cell parts that contain the green pigment, _________________________, which are responsible for producing food. _________________

Cell Structures Cell wall • Plant cells have a _____– a thick, rigid, mesh of fibers that surround the outside of the plasma membrane. – Protect the cell and give it structure – Are made from a carbohydrate called cellulose Structures and Organelles

The _____________________________ outer most side of an plant cell, (surrounds the cell membrane), that gives the cell _______, and a specific shape. _____________________________ (More rigid than cell membrane. ) _____________________________

Cell Structures Cilia and flagella • • • _____are short, numerous projections that look like _____. • Move in tandem like oars in a rowboat _______are longer and less numerous than cilia. • Move with a whip-like motion Both are made of microtubules. Structures and Organelles

Comparing Cells • Features plant cells have that animal cells generally do not: • Chloroplasts/chlorophyll • Vacuoles • Cell walls Structures and Organelles

Centrioles Large central vacuole

Organelles at Work • An understanding of different organelles allows for an understanding of cellular processes. • Protein synthesis: • Begins in the nucleus with information contained in DNA • RNA and ribosomes leave the nucleus and produce a protein on the endoplasmic reticulum. • Proteins produced in the ER are sent to Golgi apparatus for packaging. • Packaged proteins are delivered to other organelles where they serve a variety of functions. Structures and Organelles

Label the organelles of this animal cell. 1. NUCLEOLUS _________ 2. NUCLEUS _________ 3. RIBOSOMES _________ 4. VESICLE _________ 5. ROUGH _________ ER 6. GOLGI _________ BODIES 7. CELL _________ MEMBRANE 8. SMOOTH _________ ER 9. MITOCHONDRIA _________ 10. VACUOLE _________ 11. CYTOPLASM _________ 12. LYSOSOME _________ 13. CENTRIOLES _________

Essential Questions • What are the structures of a typical eukaryotic cell, and what are their functions? • What are the similarities and differences between plant and animal cells? Structures and Organelles

Section 4: Cellular Transport

Section 4: Cellular Transport Cellular transport moves substances within the cell and moves substances into and out of the cell.

Diffusion • Particles in solids, liquids, and gasses are in constant random motion. • _______is the net movement of particles from an area of high concentration to an area of _____concentration. • Additional energy is not required for diffusion because the particles are already in motion. Cellular Transport

Diffusion • When diffusion occurs over a long enough time, concentrations will become uniform, and the solution will reach ____________. • Molecules continue to move, but the overall concentration remains the same. Cellular Transport

Diffusion across the plasma membrane • • • Water can diffuse across the plasma membrane, but most other substances cannot. ___________uses transport proteins to move ions and small molecules across the plasma membrane. Diffusion and facilitated diffusion are types of passive transport – they require no additional energy. Cellular Transport

Osmosis: Diffusion of Water How osmosis works • • • _______ is the diffusion of water across a selectively permeable membrane. Water is the _______in a cell and its environment It will move across a membrane until the concentration of solute is the same on both sides. Cellular Transport

Diffusion and Osmosis • There are three types of solutions. • • _______– concentrations are equal hypertonic – solution has more solutes than a cell, cell shrivels and _______ • _____– solution has fewer solutes than a cell, cell expands and may burst hypertonic hypotonic

Active Transport • • • Sometimes substances must move from an area of lower concentration to an area of higher concentration. Movement of particles across the cell membrane, against the concentration gradient, requires energy and is called ____________. Occurs with the aid of carrier proteins, often called pumps Cellular Transport

Active Transport Na+/K+ ATPase _______ • • Are found in the plasma membrane of animal cells Maintain levels of _______(Na+) and ____(K+) inside/outside the cell Cellular Transport

Active Transport Na+/K+ ATPase pumps • • • Large molecules like sugar need to move against a concentration gradient into the cell. In a process called coupled transport, sugars can pair with Na+ ions and enter the cell through a membrane protein called a coupled channel. Allow sugars to enter through facilitated diffusion – saving energy Cellular Transport

Transport of Large Particles • ______ is the process by which a cell surrounds an object in the outside environment in a portion of the plasma membrane. • _______ is the excretion of materials at the plasma membrane. Cellular Transport

Exocytosis

Essential Questions • What are the processes of diffusion, facilitated diffusion, and active transport? • What is the effect of a hypotonic, hypertonic, or isotonic solution on a cell? • How do large particles enter and exit cells? Cellular Transport