7-1 Life Is Cellular A. Early Microscopes In 1665, Robert Hooke used an early compound microscope to look at a thin slice of cork, a plant material. Hooke’s Drawing of Cork Cells

7-1 Life Is Cellular Just Info 7-1 Life Is Cellular Just Info.-Scientist usually use existing ideas to further their ideas A. The cell theory In 1838, Matthias Schleiden concluded that all plants were made of cells. In 1839, Theodor Schwann stated that all animals were made of cells. In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells.

7-1 Life Is Cellular What is the cell theory? B. The cell theory states: All living things are composed of cells. Cells are the basic units of structure and function in living things. New cells are produced from existing cells.

7-1 Life Is Cellular Eukaryotic Cells and Prokaryotic Cells All animals and plants have eukaryotic cells. These cells have a true nucleus, and tiny organelles that all perform different jobs to help the cell. Prokaryotic cells do not have a true nucleus, and do not have organelles. They include bacteria, and are the most primitive and numerous organisms on the planet. The oldest prokaryotes(cyanobacteria) are over 3.5 billion years old.

7-1 Life Is Cellular C. Electron Microscopes Electron microscopes reveal details 1000 times smaller than those visible in light microscopes. Electron microscopy can be used to visualize only nonliving, preserved cells and tissues.

7-2 Eukaryotic Cell Structure D. Eukaryotic Cell Structures Structures within a eukaryotic cell that perform important cellular functions are known as organelles. The nucleus is the control center for the cell. The nucleus contains nearly all the cell's DNA. The Cytoplasm is the portion of the cell outside the nucleus.

Eukaryotic Cell Structures Plant Cell Nucleolus Nucleus Smooth endoplasmic reticulum Nuclear envelope Ribosome (free) Rough endoplasmic reticulum Ribosome (attached) Cell wall Golgi apparatus Cell membrane Chloroplast Mitochondrion Vacuole

Eukaryotic Cell Structures lant Cell x x x x x x x x x x x

Eukaryotic Cell Structures Animal Cell Smooth endoplasmic reticulum Nucleolus Nucleus Ribosome (free) Nuclear envelope Cell membrane Rough endoplasmic reticulum Ribosome (attached) Centrioles Golgi apparatus Mitochondrion

Eukaryotic Cell Structures Animal Cell J K A I B H C G D F E L

Make functions easy. They make something, control something, or Processes something. Nucleolus- makes ribosomes Cytoskeleton- gives support for the cell and transports information.

Nucleus- contains DNA- (deoxyribonucleic acid)- controls cell Ribosomes- make proteins Rough Endoplasmic Reticulum-makes proteins Smooth Endoplasmic Reticulum-makes lipids and packages proteins Mitochondria- makes ATP for energy Chloroplast- converts sunlight into energy and changes CO2 into sugar-(glucose) Golgi Apparatus- packages proteins Vacuole- contains the cells water and removes waste Lysosomes-breaks down toxins Centrioles-help guide cell division Nucleoulus –makes ribosomes Nuclear envelope-controls what enters and leaves the nucleus

7-2 Eukaryotic Cell Structure Nucleus Nuclear envelope The Nucleus Chromatin Nuclear envelope Nucleolus The nucleus controls most cell processes and contains the hereditary information of DNA. The DNA combines with protein to form chromatin, which is found throughout the nucleus. The small, dense region in the nucleus is the nucleolus. Nuclear pores F. The nucleus is the control center of the cell. The nucleus contains nearly all the cell's DNA and with it the coded instructions for making proteins and other important molecules.

Prokaryotic cell organism Bacteria

7-3 Cell Boundaries What is the main function of the cell membrane? F. Cell Membrane The cell membrane regulates what enters and leaves the cell and also provides protection and support. The composition of nearly all cell membranes is a double-layered sheet called a lipid bilayer or phospholipid bilayer.

7-3 Cell Boundaries What is the main function of the cell wall? G. Cell Wall The main function of the cell wall is to provide support and protection for the cell. Cell walls are found in plants, algae, fungi, and many prokaryotes. The cell wall lies outside the cell membrane. Most cell walls are porous enough to allow water, oxygen, carbon dioxide, and certain other substances to pass through easily.

7-3 Cell Boundaries What happens during diffusion? H. Diffusion Particles in a solution move from an area where they are more concentrated to an area where they are less concentrated. This process is called diffusion. When the concentration of the solute is the same throughout a system, the system has reached equilibrium.

7-3 Cell Boundaries What is osmosis? Osmosis The diffusion of water through a selectively permeable membrane. If you compare two solutions, the more concentrated solution is hypertonic-more salts or sugars (“above strength”). The more dilute solution is hypotonic- less salts or sugars (“below strength”). When concentrations of solutions are the same on both sides of a membrane, the solutions are isotonic

7-3 Cell Boundaries J. Facilitated Diffusion The movement of specific molecules across cell membranes through protein channels is known as facilitated diffusion. Facilitated Diffusion does not use energy directly. Sometimes cells move materials in the opposite direction from which the materials would normally move—that is against a concentration difference. This process is known as active transport. Energy in the form of ATP is needed Passive transport is the movement of particles without energy

7-3 Cell Boundaries K. Endocytosis and Exocytosis   Large molecules and even solid clumps of material taken into the cell by means of infoldings, or pockets, of the cell membrane is endocytosis. Phagocytosis-when white blood cells destroy foreign material. Pinocytosis- when the cell pinches off. During exocytosis, the membrane of the vacuole surrounding the material fuses with the cell membrane, forcing the contents out of the cell.

7-4 The Diversity of Cellular Life Red blood cells transport oxygen.

7-4 The Diversity of Cellular Life Muscle cells allow movement.

Levels of Organization Muscle cell Smooth muscle tissue Stomach Digestive system L. Levels of Organization The levels of organization in a multicellular organism are individual cells, tissues, organs, and organ systems. In this example, muscle cells make up smooth muscle tissue, which, along with other tissues, makes up the stomach, an organ. The stomach, in turn, is part of an organ system, the digestive system. Cells Tissue Organ Organ System