BOTANY PLANT CELLS

• Cell


  The basic building blocks of all living things
• We are made up of 30 trillion cells, and so are plants, they are also made up of cells
• Organelle


  A small, organ-like structure that performs specific functions within a cell, similar to organs in the human body
• Components of Cells


  • Plasma (cell) membrane
  • Cytoplasm
  • DNA
  • Ribosomes
• Cell wall


  Located outside of the cell membrane, serves to protect and provide structural support to the cell, filters molecules passing in and out of the cell while protecting it against mechanical stress
• Cell Membrane


  The semi-permeable membrane that is present within the cell wall, responsible for controlling the movement of substances in and out of the cell
• Nucleus


  A membrane-bound structure that is present only in eukaryotic cells, stores DNA or hereditary information required for cell division, metabolism, and growth
• Components of the Nucleus

  • Nucleolus
  • Nucleopore
• Plastids


  Membrane-bound organelles that have their own DNA, serve two important functions: starch storage and photosynthesis, and play a role in synthesizing various molecules that make up the cell's building blocks
• Types of Plastids


  • Leucoplasts
  • Chloroplasts
  • Chromoplasts
• Central Vacuole


  A large, membrane-bound structure that fills much of the plant cell
• Vesicles


  Composed of endomembrane system material, bud off from the RER, carrying material into the Golgi Apparatus
• Golgi Apparatus


  Responsible for sorting, tagging, packaging, and distributing lipids and proteins to their proper destinations, modifies proteins and lipids as they pass through, adding sugar molecule chains and tagging them with small molecules for proper sorting and destination, creates polysaccharides that are used in the cell wall and other parts of the cell
• Ribosomes


  Responsible for protein synthesis, can be either free-floating in the cytoplasm or attached to the plasma membrane or nuclear envelope, receive their "orders" for protein synthesis from the nucleus where the DNA is transcribed into messenger RNA (mRNA)
• Mitochondria


  Organelles that transform glucose, produced by photosynthesis, into ATP through oxidative phosphorylation, the main energy source for each plant cell
• Peroxisome


  Small organelles enclosed by single membranes that play a crucial role in plant cell photosynthesis, break down fatty and amino acids through oxidation reactions and detoxify many poisons that may enter the body
• Endoplasmic Reticulum


  A series of membranous sacs and tubules that modifies proteins and synthesizes lipids, has two functions: the rough ER, which incorporates proteins into membranes or secreted, and the smooth ER, which synthesizes various substances, detoxifies poisons, and stores calcium ions
• Plasmodesmata


  Small tubes that connect plant cells, providing living bridges between cells
• Cytoplasm


  The cell's entire region between the plasma membrane and the nuclear envelope, composed of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals
• Cytoskeleton


  Microtubules are protein filaments in the cytoplasm that play a crucial role in cell division, guide the construction of the cell wall, and form the basis for cilia and flagella
• Components Unique to Plant Cells

  • Cell wall
  • Central Vacuole
  • Plasmodesmata
  • Plastids
• Types of Plant Cells

  • Parenchyma cells
  • Sclerenchyma cells
  • Collenchyma cells
  • Xylem cells
  • Phloem cells
• Collenchyma Cells


  Hard or rigid cells that provide support to plants when primary walls lack a hardening agent, restraining growth
• Sclerenchyma Cells


  More flexible than collenchyma cells due to the presence of hardening agents, primarily found in plant roots, providing structural support
• Parenchyma Cells


  Vital to the growth and development of all plants, living cells that participate in the creation of leaves, the exchange of gases, the production of food, the storage of organic products, and cellular metabolism, generally more flexible than others because of their thinness
• Xylem Cells


  The transport cells in vascular plants, help in the transport of water and minerals from the roots to the leaves and other parts of the plants
• Phloem Cells


  Other transport cells in vascular plants, transport food prepared by the leaves to different parts of the plants
• Plant Tissues


  A group of similar cells, a study of cells is called histology, all cells including plants form tissues
• Meristematic Tissue


  A group of undifferentiated cells in plants that are responsible for continuous cell division and growth, the building blocks of plants, giving rise to all the different types of specialized cells that make up the plant body
• Types of Meristematic Tissue

  • Apical meristems
  • Lateral Meristems
  • The Vascular Cambium
  • The Cork Cambium
  • Intercalary Meristems
• Types of Plant Tissues

  • Simple tissues: one cell type
  • Complex tissues: multiple cell types
• Parenchyma tissue (Simple Tissue)


  Composed of parenchyma cells, the most abundant of the cell types and are found in almost all major parts of higher plants
• Specialized Tissues of Parenchyma

  • Chlorenchyma
  • Aerenchyma
• Collenchyma cells


  Like parenchyma cells, have living cytoplasm and may remain alive for a long time, their walls generally are thicker and more uneven in thickness than those of parenchyma cells
• Sclerenchyma tissue


  Consists of cells that have thick, tough, secondary walls, normally impregnated with lignin, most sclerenchyma cells are dead at maturity and function in support, two forms: sclereids and fibers
• Xylem (Complex Tissues)


  An important component of the "plumbing" and storage systems of a plant and is the chief conducting tissue throughout all organs for water and minerals absorbed by the roots, consists of a combination of parenchyma cells, fibers, vessels, tracheids, and ray cells
• Phloem tissue


  Conducts dissolved food materials (primarily sugars) produced by photosynthesis throughout the plant, composed mostly of two types of cells without secondary walls: sieve tube members and companion cells
• Epidermis (Dermal Tissues)


  The outermost layer of cells of all young plant organs, in direct contact with the environment, subject to modification by the environment and often includes several different kinds of cells
• Periderm (Dermal Tissues)


  Constitutes the outer bark and is primarily composed of somewhat rectangular and boxlike cork cells, which are dead at maturity
• Secretory cells (Secretory Cells and Tissues)


  May function individually or as part of a secretory tissue, often derived from parenchyma, can occur in a wide variety of places in a plant