What do these have in common?

From Simple to More Complex Many multicellular organisms have structures called organs that have a specific function and work with other organs. Working together, these organs carry out the life processes of the entire organism. Go to Section: 1. Some activities cannot be performed by only one person, but need a team of people. What type of activity requires a team of people to work together in order to complete a task? 2. What do you think are some characteristics of a successful team? 3. How is a multicellular organism similar to a successful team?

Levels of Organization

Cell: specialized to obtain food & oxygen, and carry out specific functions Tissue: a group of similar cells that perform a particular function Four types of tissue in living things: epithelial (skin), muscle, nerve, & connective (bone, blood, cartilage & lymph) Organs: many tissues working together to perform a function (ex. Muscle = muscle tissue, nerve tissue & connective tissue) Organ systems: group of organs working together to perform a specific task (ex. Digestive system, nervous system, & circulatory system)

Muscle cellSmooth muscle tissueStomachDigestive system Section 7- 4 Levels of Organization Go to Section:

Cells Cells = basic unit of life Can be many different sizes (always very small) Discovered by Anton Van Leeuwenhoek (1600s)

History 1665 – Robert Hooke published drawings of cork viewed through a microscope 1674 – Anton van Leeuwenhoek observed tiny living organisms in drops of pond water 1838 – Matthias Schleiden concludes that plants are made up of cells – Theodor Schwann concludes that all animals are made up of cells – Rudolph Virchow proposes that all cells come from existing cells by cellular reproduction

The Cell Theory 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.

Exceptions to the Cell Theory Within the cell there are structures that can reproduce themselves –scientists believe that mitochondria and chloroplasts evolved from more primitive life forms. Not all parts of living things are composed of “normal” cells. –Ex. Skeletal muscle contains many nuclei within one cell. Viruses are often thought of as living cells, but they can’t reproduce on their own and they do not contain any organelles.

Are All Cells Alike? All living things are made up of cells. Some organisms are composed of only one cell. Other organisms are made up of many cells. 1. What are the advantages of a one-celled organism? 2. What are the advantages of an organism that is made up of many cells? Section 7-1 Interest Grabber Go to Section:

Unicellular vs. Multicellular Unicellular (one-celled) organism Multicellular (many-celled) organisms

Multicellular Organisms The cells in a multicellular organism are interdependent (can not live on their own) (they depend on each other like players on a team) Cell specialization = each type of specialized cell performs separate roles or functions within the organism, has a different number of each organelle depending on function Ex: red blood cells, nerve cells, muscle cells, pancreatic cells – have enormous amounts of organelles involved in their functions

Plant vs. Animal Cell

Unicellular Organisms One-celled organism is able to function despite lacking the levels of organization present in more complex organisms. The structures present in some single-celled organisms act in a manner similar to the tissues and systems found in multicellular organisms, thus enabling them to perform all of the life processes needed to maintain homeostasis. They do everything you would expect a living thing to do. Ex: yeast

Unicellular organisms Paramecium Euglena

Prokaryotes vs. Eukaryotes Cells ProkaryotesEukaryotes No nucleus Have a Nucleus Smaller and simpler Larger and complex Have cell membranes Have organelles Have cytoplasm Single or Multi- celled Ex. Bacteria Ex. Plants, animals & fungi

Prokaryotic Cell Cell membrane Cytoplasm Nucleus Organelles Eukaryotic Cell Section 7-1 Prokaryotic and Eukaryotic Cells Go to Section:

Division of Labor A cell is made up of many parts with different functions that work together. Similarly, the parts of a city work together to carry out different functions. 1. What are some of the different parts of a city? What are the functions of these city parts? 2. How do the functions of these city parts correspond to the functions of certain cell parts? Section 7-2 Go to Section:

Structures Cells have particular structures that perform specific jobs. These structures perform the actual work of the cell. Just as systems are coordinated and work together, cell parts must also be coordinated and work together. These structures are called organelles.

Cell Organelles What is an organelle? –They are specialized microscopic structures within cells –They are contained within the cytoplasm exception- nucleolus is contained within the nucleus –They have characteristic structures and functions.

Cell Structures A.Cell Wall B. Cell Membrane C.Nucleus 1.Chromatin and Chromosomes 2.Nucleolus 3.Nuclear Envelope D.Cytoskeleton E.Organelles in the Cytoplasm 1.Ribosomes 2.Endoplasmic Reticulum 3.Golgi Apparatus 4.Lysosomes 5.Vacuoles 6.Chloroplasts 7.Mitochondria Section 7-2 Go to Section:

STRUCTURE OF ORGANELLES TWO TYPES: MEMBRANE BOUND ORGANELLES CELL PARTS NOT SURROUNDED BY A MEMBRANE

Cell parts not bound by a membrane 1. Cell wall 2. Cell membrane 3. Cytoplasm 4. Cytoskeleton

Cell Wall Strong layer on the outside of plant, algae, fungi and many prokaryotic cells (not in animal cells) Support and protect the cell Allow water, oxygen, carbon dioxide and other substances to pass through Made from fibers of carbohydrates and proteins, for example, cellulose (tough carbohydrate fiber in plant cell walls) found in paper

Cell Membrane Thin, flexible barrier around cells (inside cell wall on plant cells) Provides protections and support Helps maintain the chemical balance between materials inside and outside the cell by removing wastes from the cell Selectively permeable = allows only certain material in or out of the cell Made up of a lipid bilayer with some proteins scattered throughout

Cytoplasm The gel-like material inside the cell (not including the nucleus and organelles) Transports materials throughout the cell Holds organelles Constantly moving or flowing

Cytoskeleton Helps support some cells Network of protein filaments that helps keep the cell’s shape Involved in many forms of cell movement Microtubules – hollow tubes of protein that serve as “tracks” for moving organelles, form centrioles in animal cells to help separate chromosomes during cell division, form cilia or flagella to move Microfilaments – long, thinner fibers functioning in support and movement within the cell

Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Michondrion Section 7-2 Cytoskeleton Go to Section:

Membrane Bound Organelles Specialized structures that perform cellular functions 1.Nucleus 2. Ribosomes 3.Endoplasmic Reticulum 4.Golgi Apparatus 5.Lysosomes 6.Vacuoles 7.Chloroplasts 8.Mitochondria

Nucleus Large structure that contains the cell’s genetic material or hereditary information (DNA) & instructions for making proteins (RNA) Controls the cell’s activities Chromatin – granular material visible with nucleus made up of DNA bound to protein Chromosomes – formed by chromatin during cellular reproduction (genetic information to be passed on to the next generation) Nucleolus – small, dense region within the nucleus where ribosome assembly begins Nuclear Envelope – double membrane around the nucleus with nuclear pores to allow material to move through (including RNA)

Ribosomes Made of RNA and protein Build proteins on ribosome from proteins and RNA (coded instructions from the nucleus)

Endoplasmic Reticulum Internal membrane making parts of the cell membrane and modifying proteins Rough ER – with ribosomes to make proteins, has a rough appearance through the electron microscope As each protein is made it crosses the ER membrane and enters the ER for chemical modification Smooth ER – lacks ribosomes and appear smooth under the electron microscope Contain enzymes to perform specialized tasks such as making lipids and breaking down toxic substances.

Golgi Apparatus Stacked membranes with enzymes to package proteins by attaching carbohydrates and lipids

Lysosomes Small spheres filled with enzymes to break down lipids, carbohydrates, and proteins from food into smaller particles to be used by the rest of the cell, as well as worn-out organelles and wastes

Vacuoles Sac-like structure to store materials including water, salts, proteins, and carbohydrates Plant cells contain a large central vacuole with enough pressure to make the cell rigid Animal cells contain smaller vesicles that transport substances within the cell

MEMBRANE FLOW GOLGI Proteins are made at ribosomes Proteins sent through ER to Golgi Secretory vessicles remove protein from cell by exocytosis. nucleus

Chloroplasts Use energy from sunlight with carbon dioxide and water to make food (carbohydrates) and oxygen through photosynthesis in plant cells and some other cells (not in animal/fungi cells) Double envelop membrane contain the green pigment chlorophyll Contain some of its own genetic information (DNA)

Mitochondria Use food to make energy (ATP) for growth, development, and movement Double envelop membrane Contain some of its own genetic information (DNA)

ENDOSYMBIOSIS LIVING TOGETHER SINCE CHLOROPLASTS AND MITOCHONDRIA HAVE THEIR OWN DNA, THEY MIGHT HAVE ORIGINATED AS FREE LIVING ORGANISMS. CHLOROPLAST AND MITOCHONDRIA DO NOT HAVE ENOUGH DNA TO LIVE ALONE, BUT MAY HAVE AT ONE POINT IN TIME A LONG TIME AGO. THEORY OF CHLOROPLAST ENDOSYMBIOSIS: THEY GET CAUGHT INSIDE A HETEROTROPH (CELLS THAT DO NOT MAKE FOOD) AND THEY STAY THERE. CHLOROPLAST PROVIDES FOOD AND CELL PROVIDES PROTECTION OVER TIME CHLOROPLASTS LOSE THE ABILITY TO LIVE INDEPENDENTLY.

Plant Cell Nuclear envelope Ribosome (attached) Ribosome (free) Smooth endoplasmic reticulum Nucleus Rough endoplasmic reticulum Nucleolus Golgi apparatus Mitochondrian Cell wall Cell Membrane Chloroplast Vacuole Section 7-2 Go to Section:

Animal Cell Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth endoplasmic reticulum Mitochondrian Cell Membrane Ribosome (free) Ribosome (attached) Section 7-2 Go to Section:

Onion Cells

Cheek Cells

ProkaryotesEukaryotes Cell membrane Ribosomes Cell wall Cytoplasm Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Animal CellsPlant Cells Lysosomes Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Vacuoles Mitochondria Cytoskeleton Cell Wall Chloroplasts Section 7-2 Go to Section: What did you observe in the onion cells and cheek cells?

What kind of cell is it? Prokaryote/Eukaryote & Animal (like)/Plant (like) & Unicellular/Multicellular

What would happen if something didn’t work right? A.Cell Wall B. Cell Membrane C.Nucleus 1.Chromatin and Chromosomes 2.Nucleolus 3.Nuclear Envelope D.Cytoskeleton E.Organelles in the Cytoplasm 1.Ribosomes 2.Endoplasmic Reticulum 3.Golgi Apparatus 4.Lysosomes 5.Vacuoles 6.Chloroplasts 7.Mitochondria