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The Discovery of the Cell ------------------------- The Cell Theory --------------- 1. All living organisms are made up of one or more cells. 2. Cells are the basic units of structure, function and organization in all living organisms. 3. Cells come from pre-existing cells. All Living Or...

The Discovery of the Cell ------------------------- The Cell Theory --------------- 1. All living organisms are made up of one or more cells. 2. Cells are the basic units of structure, function and organization in all living organisms. 3. Cells come from pre-existing cells. All Living Organisms are Made Up of One or More Cells ----------------------------------------------------- Cells are the Basic Units of Structure, Function, and Organization in All Living Organisms ------------------------------------------------------------------------------------------ Cells come from Pre-existing Cells ---------------------------------- The Modern Principles of the Cell Theory include the following: --------------------------------------------------------------- 1. All living things are made up of one or more cells. 2. The cell is all living organisms\' fundamental, structural, and functional unit. 3. All cells come from pre-existing cells, by cell division. 4. The activity of the organism is the total activity of the independent cells of organism. 5. All energy flow of life occurs within the cell. 6. The cells contain hereditary information and is passed on from one to another during cell division. 7. The chemical composition of cell are basically the same in organisms of similar species. **Cell Number, Shape, and Size Cell Number** ============================================ **Cell Shape** ============== **Cell Size** ============= **Functions of a Cell** ======================= 1. **Structure and Support.** You know a house is made of walls, beams etc. Similarly, a living organism is made up of cells. Though there are certain cells such as collenchyma and sclerenchyma are present for offering structural support however in general too, all cells generally provide the structural basis of all living organisms. 2. **Growth.** In complex organisms such as mammals, the tissues grow by simple multiplication of cells. Therefore, cells are responsible for the growth of the organism via the process of mitosis. 3. **Transport.** Cells import nutrients that are used in different chemical process which takes place inside the cell. As a result of these processes, a waste product is produced. Cells then work to get rid of waste. In this manner, the micromolecules like oxygen, carbon dioxide, and ethanol pass through the cell (plasma) membrane) by passive transport. On the other hand, macromolecules, like the proteins and polysaccharides, go in and out of the cell via active transport. 4. **Energy Production**. Cell is responsible for metabolism that includes all the chemical reactions that take place inside an organism to keep it alive. 5. **Reproduction.** A cell helps in reproduction by the process (in more evolved organisms) and meiosis. 1. **Nucleus** is the largest and most distinct feature of both animal and plant cells which is usually centrally located and serves as the control center of the cell. It is responsible for cell division and where DNA is located. It is enclosed with a nuclear membrane. The following are the parts of the nucleus and their functions: a. b. c. d. Nucleus 2. **Cytoplasm** is the material between the nucleus and the outer boundary where organelles are found. 3. **Cell (plasma) membrane** is a semipermeable membrane. It serves to t the organelles in the cytoplasm and determines which material can pass in and out of the cell. It has an outer membrane regulates exchange of materials between the cell's internal and external environment. It also permits cell to cell adhesion and intercellular communication. Cell (plasma) membrane is composed of lipids, proteins and carbohydrates. ### Endoplasmic Reticulum and Ribosomes ### Golgi Body or Golgi Apparatus ### ### Mitochondria ### Lysosomes ### Vacuoles Plant Vacuole Animal Vacuo ### Centrioles ### Cell Wall ### Chloroplasts ### ### Cytoskeleton ### Quarter 1 -- Module 2 The Different Types of Cells **[THE DIFFERENT TYPES OF CELLS]** 1. **Eukaryotic Cells** **DNA Location --** an organelle called the [nucleus](#page-dbmt8ck1), which is bounded by a double membrane. **Definition of Terms & Origin of Words --** means \"true nucleus\" **From Greek words:** - **\"eu\" (true)** - **\"karyon\" (kernel or nucleus)** **Interior of Cell:** - region between the nucleus and the plasma membrane. - a variety of organelles of specialized form and function are suspended in cytosol Within the cytoplasm of a eukaryotic cell - A type of cell with a membrane-enclosed nucleus and organelles. - Organisms under Domain Eukarya (protists, fungi, plants, and animals) have eukaryotic cells. They are called eukaryotes. 2. **Prokaryotic cells** **DNA Location --** concentrated in a non- membrane enclosed region, called the [nucleoid](#page-dbmt8ck0). **Definition of Terms & Origin of Words** --\"before nucleus\" **From Greek words:** - **\"pro\" (before)** - **\"karyon\" (kernel or nucleus)** **Interior of Cell:** The membrane-bounded structures are absent in prokaryotic cells, however despite the absence of organelles, the prokaryotic cytoplasm: - is not a formless soup of cytoplasm - appears to be organized into different regions. - does not have a true nucleus - DNA is in an unbound region called the nucleoid. - It does not have membrane-bound organelles either. - Single--cell organisms under Domain Bacteria and Domain Archaea have prokaryotic cells. They are called prokaryotes. **Distinguishing Features of a Eukaryotic Cell vs. Prokaryotic Cell** 1. **Size of the Cell** 2. **Cell Membrane** 3. **Nucleus** 4. **Energy Metabolism** 5. **Cell Division** 6. **Cytoplasm** 7. **Representative Organisms** **Common Types of Animal Cells** 1. **Skin Cells** **A. Melanocytes** - produce the hormone melanin which is responsible for skin pigmentation (color) and photoreception of the skin and eyes. **B. Keratinocytes -** generate a protein called keratin which helps make the skin an effective layer of protection for the body. **A. Adyposcytes -** store energy in the form of fat, cushion internal organs, and kept the body warm(insulation) which is found in the subcutaneous layer under the skin; around the heart, kidneys, and nerve tissue; in yellow bone marrow and breast tissue; and within the buttocks, thighs, and abdominal cavity 1. **Bone Cells -** responsible for locomotion (movement), support and protection of large tissues, calcium and phosphate storage, and the harbor of bone marrow. 1. **Vascular Tissue** - transports substances like water, minerals, and sugar from one extreme end of the plant to the other. **A. Xylem Tissue** - Water-conducting cells - transports water and nutrients from the plant-soil interface to the stems and leaves - provides mechanical support for the water transported upward and the plant itself **B. Phloem Tissue** - acts as a transport system for soluble organic compounds within vascular plants - move sucrose sugar and proteins from the leaves where they are produced through photosynthesis to the rest of the plant 2. **Dermal Tissue** - covers and protects the plant, and controls gas exchange and water absorption (in roots) - prevents evaporative water loss in the stem and leaves of plants due to the presence of a waxy covering called cuticle 3. **Ground Tissue** - carries out different functions based on the cell type (parenchyma, collenchyma, and sclerenchyma) and the location in the plant **A. Parenchyma Cells** - make up plant leaves and is the site of photosynthesis, thus, contains large quantities of chloroplast - sites of sugar or starch storage in roots and are called pith (in the root center) or cortex (in the root edges). **Meristem** - Meristem, region of cells capable of division and growth in plants. Meristems are classified by their location in the plant as apical (located at the root and shoot tips), lateral (in the vascular and cork cambia), and intercalary (at internodes, or stem regions between the places at which leaves attach. There are three primary meristems: the protoderm, which will become the epidermis; the ground meristem, which will form the ground tissues comprising parenchyma, collenchyma, and sclerenchyma cells; and the procambium, which will become the vascular tissues (xylem and phloem). Unlike most animals, plants continue to grow throughout their entire life span because of the unlimited division of meristematic regions. ### Quarter 1 -- Module 3 Cell Modifications The Cell Cycle -- -- ### Common Examples of Modified Cells and Tissues in Animals 1. **Cilia** ### Flagella ### Villi ### Leukocyte ### Red Blood Cells ### Nerve Cells ### Muscle Cells ### Common Examples of Modified Cells and Tissues in Plants 8. **Root Hairs** ### Guard Cells ### Cuticle ### Xylem and Phloem -- -- -- -- -- -- ### ### ### ### ### ### ### ### ### ### ### ### ### ### The Cell Cycle The Cell Cycle ------------------------------------- Interphase ---------- 1. G1 Phase - G1 phase is also known as the first gap. - Little change is observed in the microscopic level. - The cell grows and accumulates the building blocks of chromosomal DNA and the associated proteins as well as enough energy reserves to complete the task of replicating each chromosome in the nucleus. 2. S Phase - S phase is also known as the synthesis. - DNA is replicated which results in the formation of identical pairs of DNA molecules, sister chromatids, that are firmly attached to the centromeric region. - Each of the 46 chromosomes (23 pairs) is replicated by the cell. 3. G2 Phase - G2 phase is also known as the second gap. - Cell grows more. - The cell replenishes its energy, stores, and synthesizes proteins necessary for chromosome manipulation. - The cytoskeleton is dismantled to provide resources for the mitotic phase. - Organelles and proteins develop in preparation for cell division. G0 phase -------- Mitotic Phase ------------- 1\. Mitosis is a process of nuclear division in eukaryotic cells which is conventionally divided into four stages: prophase, metaphase, anaphase, and telophase. Mitosis conserves chromosome number by allocating replicated chromosomes equally to each of the daughter nuclei. The Cell Cycle Control System ----------------------------- The sequential events of the cell cycle are directed by a distinct cell cycle control system, which is like a clock. The clock has specific checkpoints where the cell cycle stops until a go -- ahead signal is received. b\. If a cell receives a go-ahead signal at the G1 checkpoint, the cell continues in the cell cycle. c\. If a cell does not receive a go-ahead signal at the G1 checkpoint, the cell exits the cell cycle and goes into G0, a nondividing state. ### Quarter 1 -- Module 4 Cell Division