Cells! Chapter 7

What is a cell? A cell is the basic unit of life. The smallest living thing. All living things are made of cells

History of Cells

How did we find cells? 1600s began to use microscopes to observe living things Robert Hooke (1665) Came up with the phrase ‘cell’ Built a microscope that allowed him to look at very tiny objects Sliced a very thin piece of cork and looked at it through his microscope

Anton van Leeuwenhoek (1674) A fabric merchant Looked at pond scum. First to discover unicellular organisms. He named them “animacules” or “little animals”.

Schleiden and Schwann Matthias Schleiden (1838) A German scientist who studied cells. Concluded that all plants are made of cells Theodor Schwann (1839) *Concluded that all animals are made of cells

Rudolph Virchow 1855 German doctor Discovered that cells could not develop from anything but other cells - This idea completed the cell theory

Cell Theory All living things are composed of cells Cells are the basic units of structure and function in living things New cells come from existing cells

Chapter 7 Vocabulary Pages 169-193 Please add the following 15 words to your notes! Cell Cell Theory Eukaryote Prokaryote Organelle Cell Specialization Tissue Organ  Organ System Diffusion  Osmosis Equilibrium Isotonic Hypertonic Hypotonic

Diversity of Cellular Life Unicellular Organisms Made of a single cell Majority of life on Earth Multi-cellular Organisms Made of many cells Depend on specialized cells

Plant v. Animal Cells Read through the articles about plant and animal cells. From the reading list 5 differences between a plant and animal cell. On the plant cell color: Nucleolus, nucleus, chloroplast, vacuole, Rough ER, smooth ER, cell wall, cytoplasm On the animal cell color: Microfilaments, lysosome, ribosome, chromatin, centrioles, microtubules, mitochondria, nuclear pores, nuclear envelope, cell membrane, golgi complex

Organelle Flashcards At your desk you will find all the materials you need to set up your flashcards. Please cut out: 11 Animal cells 8 Plant cells Glue the cut out cells onto one side of a flashcard. You should have 19 total We will fill out the cards together as a class when everyone has them put together.

Organelles Specialized structure that performs important functions in the eukaryotic cell Golgi Apparatus (Complex) Products of the endoplasmic reticulum are modified, stored or sent to other destinations outside of cell Found in plant and animal cells

Cell Membrane Cytoplasm Allows passage of oxygen, nutrients, and wastes in and out of the cell Provides protection and support Found in plant and animal cells Cytoplasm Portion of the cell outside the nucleus Helps to maintain cellular shape

Nuclear Envelope (membrane) Surrounds nucleus, separates from cytoplasm Allows material to move in and out of the nucleus Provides support and protection for the nucleus Found in plant and animal cells Nuclear Pore Holes which allow material to move into or out of the nucleus Cell Wall Protects the plant cell, maintains its shape, prevents excessive water intake Found only in plant cells

Endoplasmic Reticulum Where lipids are assembled; proteins and other materials released from cell Smooth: lacks ribosomes; synthesizes lipids, metabolizes carbohydrates, detoxification Rough: ribosomes attached to surface; responsible for protein production; modifies proteins Found near nucleus Found in plant and animal cells

Mitochondria Nucleus Site of cellular respiration (generates energy) Convert chemical energy in food to a form cells can use Found in plant and animal cells Nucleus Contains all genes (genetic information), chromatin, chromosomes and nucleolus Controls protein synthesis

Chloroplast Site of photosynthesis, convert solar energy to chemical energy Found only in plant cells Lysosome Digest macromolecules (lipids, proteins, carbohydrates) Found only in animal cells

Ribosome Vacuole Where proteins are made Found in plant and animal cells Vacuole Stores materials (water, salts, proteins, carbohydrates) Large size in plants (support) Plant cells and some animal cells

Nucleolus Chromatin Inside nucleus Synthesizes components of ribosomes Found in plant and animal cells Chromatin In nucleus Made of DNA + Protein which gives us chromosomes. Contain instructions for traits & characteristics

Help cell division –only 2 in cell Only found in animal cells. Centriole Help cell division –only 2 in cell Only found in animal cells. Cytoskeleton Microtubule maintain cell shape and help form the spindle in cell division Microfilament aid in movement and support

Levels of Organization Individual Cells Tissues Cells grouped together A group of similar cells that perform a particular function Organs Tissues work together Organ Systems Group of organs that work together to perform a specific function

Cell specialization: cells develop in different ways to perform different tasks Animal cells: red blood cells (transport oxygen), pancreas (protein production), muscle cells (movement) Plant cells: guard cells (regulate exchange in leaves)

Cell Boundaries Cell Membrane Cell Wall Thin flexible barrier that surrounds a cell Regulates what enters and leaves the cell, provides protection and support Cell Wall Strong supporting layer around the cell membrane

Cell Membrane Made of two layers (lipid bilayer) Gives cell membranes a flexible structure that forms a strong barrier Contains protein and carbohydrate molecules Helps materials cross the membrane

Cell Wall Found outside the cell membrane (plants) Main function to provide support and protection Allows water, oxygen, carbon dioxide to pass through Made from carbohydrates and protein

Diffusion Movement of dissolved molecules from one side of cell membrane to another Particles move from an area where they are more concentrated to an area where they are less concentrated Substances diffuse across a membrane without the cell using any energy

Facilitated Diffusion Cell membrane has certain channels that make it easy for certain molecules to cross the membrane Will only occur if there is a higher concentration on one side of the membrane

Active Transport Small molecules and ions are carried across membranes by proteins Requires energy, cells use majority of their energy for transport Endocytosis Process of taking material into the cell by folding of cell membrane Exocytosis Membrane of vacuole fuses with cell membrane forcing contents out of cell

Osmosis Diffusion of water across a selectively permeable membrane Most membranes selectively permeable some substances can pass through and others cannot Water passes easily across most membranes

Osmosis How Osmosis works… Water will move across the membrane until equilibrium is reached Moves from high to low concentration Osmotic pressure: pressure on the hypertonic side of a selectively permeable membrane

Solutions Hypertonic: side of the membrane with more molecules; “above strength” Hypotonic: the side of the membrane with less molecules; “below strength” Isotonic: concentrations the same on both sides of the membrane; “same strength”

Osmosis Lab Tomorrow we will be completing a lab in class that illustrates the process of osmosis. Today you should… Read through entire lab procedure Complete all pre-lab questions Write a hypothesis Identify manipulated, responding and control variables.