Idea – get them to do the slides for the organelles!

CELL THEORY  All living things are made up of one or more cells.  The chemical reactions of a living organism take place within cells.  All cells are formed from pre-existing cells and these cells contain the hereditary information.  Cells vary in size, shape, function and life span  The cell is the smallest organisational unit

Properties of cells Most cells have some common features: Plasma membrane The cell membrane is a structure that forms the outer boundary of the cell and allows only certain materials to move into and out of the cell. Food, oxygen and water move into the cell through the membrane. Waste products also leave through the membrane. Cells that perform photosynthesis (plants and some protists) take in carbon dioxide through the cell membrane instead of oxygen. The cell membrane is like a gate because it allows only certain materials to move in and out of the cell

Properties of cells

Most cells have some common features: Cytoplasm Gel-like material inside the cell membrane and outside the nucleus. Cytoplasm contains a large amount of water and many chemicals and structures that carry out the life processes in the cell. These structures that the cytoplasm contains are called organelles. Cytoplasm is the jelly-like material inside the cell (but unlike gelatin it does flow; cytoplasm constantly moves or streams. Properties of cells

Most cells have some common features: Nucleus The nucleus is a highly specialized organelle that serves as the information and administrative center of the cell. This organelle has two major functions. It stores the cell's hereditary material, or DNA, and it coordinates the cell's activities, which include intermediary metabolism, growth, protein synthesis, and reproduction (cell division). Properties of cells The largest organelle in the cytoplasm of a cell is usually the nucleus, a structure that directs all the activities of the cell. The nucleus contains genetic blueprints for the operations of the cell.

Properties of cells Most cells have some common features: Flagella or Cilia Many cells have extensions called flagella (whip-like processes) or cilia (small hair-like structures) that are used for movement either of the cell itself or of the medium surrounding the cell.

Types of cells There are two types of cells Organisms are grouped according to what type of cell they have Prokaryotes - have cells with a ‘primitive’ nucleus and lack membrane- bound organelles. Prokaryote cells contain a single, circular DNA chromosome. (unicellular or simple multicellular organisms - Bacteria, cyanobacteria) (pic pg 23) Eukaryotes- have cells that are usually much larger and more complex than prokaryote cells. They have a membrane-bound nucleus, and their cytoplasm includes specialised membrane-bound structures called organelles. Many of their cellular processes take place within these membrane-bound subcellular compartments. (protists, fungi, plants & animals

Cell Organelles Overview

Mitochondrion Cells require a continuous supply of energy. Organelles where: – food molecules are broken down. – energy is released. The energy is then stored in other molecules that can power cell reactions easily. Mitochondria (plural) – use when you refer to more than one mitochondrion.

Nucleus Usually the largest organelle in the cytoplasm of a cell. Directs all the activities of the cell. Contains genetic blueprints for the operations of the cell.

Centrioles Self-replicating organelles Made up of nine bundles of microtubules Found only in animal cells. Help in organizing cell division.

Cell membrane Forms the outer boundary of the cell. Allows only certain materials to move into and out of the cell. Food, oxygen and water move into the cell through the membrane. Waste products also leave through the membrane. Cells that perform photosynthesis (plants and some protists) take in carbon dioxide through the cell membrane instead of oxygen.

Cell wall The cell wall is a rigid structure outside the cell membrane that supports and protects the cell (for plants, fungi, and some protists and bacteria but NOT animals). Animal cells DO NOT have a cell wall. The cell wall is made of tough cellulose fibres and other materials made by the cell. Note: fungal cell walls contain chitin instead of cellulose.

Cytoplasm Gel-like material inside the cell membrane and outside the nucleus. Cytoplasm is the jelly-like material inside the cell (but unlike gelatin it does flow; cytoplasm constantly moves or streams. Contains a large amount of water (cytosol) and many chemicals and structures that carry out the life processes in the cell. The structures that the cytoplasm contains are called organelles.

Endoplasmic reticulum A folded membrane that moves materials around in the cell. Extends from the nucleus to the cell membrane and takes up quite a bit of space in some cells. Two different types: Smooth ER and Rough ER. Rough ER has ribosomes attached to its outer membrane, while Smooth ER does not.

Golgi bodies Golgi bodies package and move proteins In a business, products are made, packaged, and moved to loading docks to be carried away. In cells, structures called Golgi Bodies are stacks of membrane-covered sacs that package and move proteins to the outside of the cell. When something is secreted, it is given off by the cell. Note: Golgi Bodies are sometimes referred to as Golgi Apparatus.

Vesicle Vesicles transport proteins.

Chloroplasts Chloroplasts take in sunlight, water and carbon dioxide to make oxygen and sugar. This process is called photosynthesis. A plant's chloroplasts convert light energy into chemical energy. Contain a green pigment called chlorophyll. This is what makes plants green.

Vacuole Acts as a temporary storage space for the cell. Vacuoles store water, food, pigments, waste or other materials. Vacuoles are large in plant cells and small in animal cells. Vacuoles can also be found in fungi and protists.

Lysosomes An active cell constantly produces waste products. Contain chemicals (enzymes) that: – digest wastes and worn-out cell parts – break down food.

Ribosome One chemical that takes part in nearly every cell activity is protein. Proteins are needed for chemical reactions that take place in the cytoplasm. Cells make their own proteins on small structures in the cytoplasm called ribosomes.

Cilia and Flagella For single-celled eukaryotes, cilia and flagella are essential for the locomotion of individual organisms. In multicellular organisms, cilia function to move fluid or materials past an immobile cell as well as moving a cell or group of cells. – Cilia lining nasal passage – Sperm

Microfilaments Solid rods made of globular proteins called actin and are common to all eukaryotic cells. Long chains of the molecules are intertwined in a helix to form individual microfilaments. Filaments are primarily structural in function and are an important component of the cytoskeleton, along with microtubules. In association with myosin, microfilaments help to generate the forces used in cellular contraction and basic cell movements. They enable a dividing cell to pinch off into two cells and are involved in amoeboid movements of certain types of cells. They also enable the contractions of muscle cells.

Microtubules Straight, hollow cylinders are found throughout the cytoplasm of all eukaryotic cells (prokaryotes don't have them) and perform a number of functions. Gives structure and shape to a cell, Serve as conveyor belts moving other organelles through the cytoplasm Are the major components of cilia and flagella, and participate in the formation of spindle fibers during cell division (mitosis). These filaments are composed of linear polymers of tubulin, which are globular proteins, and can increase or decease in length by adding or removing tubulin proteins.

Plant cell

Animal cell

Copy down the characteristics of cells in the 5 kingdoms pg 26 HW - Q 1- 8