Learning Objectives 1. Discuss facts about cells and the organisation - PowerPoint PPT Presentation

Learning Objectives 1. Discuss facts about cells and the organisation of the body 2. Outline the functions of the main cell components 3. Label a human cell

LO1: Discuss facts about cells and the organisation of the body 5 minutes Starter – True or False Decide if you think the following statements are TRUE or false. 1. Groups of cells are known as tissues 2. There are 5 different types of cells in the human body 3. Cells are too small to be seen without magnification 4. Tissues are grouped together to form an organ Name and explain the different 5. Cells do not contain genetic material types of tissue in the body

LO1: Discuss facts about cells and the organisation of the body Organisation of the body Make notes • Every person is made up of billions of microscopic units called cells. The cells carry out many chemical reactions and processes that allow us to live. • Cells don’t usually exist in isolation, they are usually grouped together with other similar cells carrying out particular tasks. Groups of cells are known as tissues • Different types of tissues are commonly grouped together to form an organ, which carries out a particular function. • Groups of organs that are responsible for major tasks or functions in the body are called body systems.

LO1: Discuss facts about cells and the organisation of the body Interesting Cell Facts There are more Cells are too bacterial cells in the small to be body than human seen without cells. magnification. There are about 200 Cells contain genetic different types of cells in material. the human body. The largest cell in the human body is the female ovum.

LO2: Outline the functions of the main cell components Task 1: Typical Human Cell 20 minutes https://www.youtube.com/watch?v=HBvfBB_oSTc&t=29s https://www.youtube.com/watch?v=URUJD5NEXC8 Watch the videos and make notes on the following: ● ● Cell Membrane Endoplasmic Reticulum (Rough & ● Cytoplasm Smooth) Research online to find ● ● Nucleus Golgi Apparatus further detail on each ● ● Nucleolus Vacuole ● ● Ribosomes Lisosomes area of the human cell ● Mitochondria

LO2: Outline the functions of the main cell components Cell/Plasma Membrane 5 minutes ● The cell membrane surrounds the cell and keeps all the components inside the cell and prevents some materials out of the cell. ● The cell membrane allows some materials in and out of the cell and so it is not a solid structure. ● The cell membrane is a phospholipid-protein bi-layer. ● Phospholipids are small, fatty molecules in two layers, with protein molecules inserted at intervals through the bi-layer. ● Scientists use the fluid mosaic model to describe the organization of phospholipids and proteins. ● The model shows you that phospholipid molecules are shaped with a head Check your and a tail region. notes & add ● The head section of the molecule likes water (hydrophilic) while the tail any missing detail does not (hydrophobic).

LO2: Outline the functions of the main cell components 2 minutes Cell/Plasma Membrane ● Because the tails want to avoid water, they tend to stick to each other and let the heads face the watery (aqueous) areas inside and outside of the cell. ● The two surfaces of molecules create the lipid bilayer. ● Protein molecules often form channels through the membrane for substances to pass to and from the cells. This structure is often termed the ‘fluid mosaic model’ of the cell membrane. Check your notes & add any missing detail

LO2: Outline the functions of the main cell component Cytoplasm 5 minutes ● Cytoplasm is the semi-fluid that fills a cell. ● It is likened to a gel and capable of flowing slowly and keeps all the organelles suspended in the cell. ● Many chemical reactions are carried out in the cytoplasm (metabolism). ● Complex stored sugars such as glycogen and melanin (the dark pigment responsible for skin and hair colour) are found in cytoplasm. ● It uses its dissolved enzymes to break down all of those larger molecules. The products can then be used by the organelles of the cell. Check your ● Glucose may exist in the cytoplasm but the mitochondria can't use it for fuel. notes & add The cytoplasm has enzymes that break glucose down into pyruvate any missing molecules that are then sent to the mitochondria. detail

LO2: Outline the functions of the main cell components Nucleus 5 minutes ● The cell nucleus is a membrane bound structure that contains the cell's hereditary information and controls the cell's growth and reproduction. ● Chromosomes are located within the nucleus. Chromosomes consists of DNA, which contains hereditary information and instructions for cell growth, development, and reproduction. When a cell is "resting" i.e. not dividing, the chromosomes are organized into long entangled structures called chromatin. ● When a cell is dividing, the chromatin network separates into distinct black threads known as chromosomes. ● There are 23 pairs of chromosomes in a human cell, containing specific Check your sequence of deoxyribonucleic acid (DNA), responsible for all our inherited characteristics such as hair colour and eye colour. These sequences of notes & add DNA are our genes. any missing detail

LO2: Outline the functions of the main cell components 5 minutes Mitochondria ● Every cell in the body has at least 1000 of these rod-shaped or spherical bodies, and very energy active cells (like muscles and liver cells) will have many more. ● Mitochondria are concerned with energy release. ● Each has a double-layered membrane like the cell membrane but the inner layer is folded at intervals, producing a series of ‘shelves’ or ridges known as cristae. ● The enzymes responsible for the end stages of glucose oxidation (for cell reproduction) are located on the cristae. ● The energy released from glucose is trapped and stored until required by a ‘chemical battery’ called adenosine triphosphate (ATP). ● When energy is required for building complex molecules or doing work like Check your contracting muscles, ATP breaks down to adenosine diphosphate (ADP), notes & add releasing energy to build chemical bonds. ADP is then recycled. any missing detail

LO2: Outline the functions of the main cell components Endoplasmic Reticulum 5 minutes ❖ There are two variations, called rough and smooth ER. ‘Endo’ means within and ‘reticulum’ is a technical term for a network. ❖ ER is a branching network that fills the cell interior. ❖ The channels form passageways for transporting materials to and from different parts of the cell. ❖ Rough ER is so called because it is studded with tiny black bodies, known as ribosomes, and has the function of making cell proteins and acting as a temporary storage area. Some times sugars are added to the proteins to make glycoproteins, in secretions such as mucus. ❖ Smooth ER has no attached ribosomes and is involved in the metabolism of lipids or fat.

LO2: Outline the functions of the main cell components Golgi Apparatus 2 minutes ● This appears as a series of flattened, fluid-filled sacs stacked like pancakes. Many tiny fluid filled globules or bags lie close to stack and these are often known as vesicles. ● The Golgi apparatus packages proteins for delivery to other organelles and is responsible for producing lysosomes.

LO2: Outline the functions of the main cell components Lysosomes 5 minutes ● Lysosomes can be found in all parts of the cell cytoplasm and are small vesicles. ● They contain powerful enzymes capable of digesting all major chemical components of living cells, they are sometimes called ‘suicide bags’. ● Lysosomes can travel freely throughout the cell and, by releasing their contents, they can destroy old or damaged organelles and even entire cells. ● Another of their functions is to destroy bacteria and other foreign materials, such as carbon particles, that enter the cell. They do this by taking the foreign matter into their vesicles. After destroying the foreign matter with their enzymes, they release the digested material. ● Some types of white blood cells - phagocytes (eating cells), monocytes and macrophages (large eaters) are loaded with lysosomes because their function is to destroy bacteria, viruses and foreign material entering the body cells and tissues. ● Many disease-causing agents are thought to be capable of damaging lysosome membranes, bringing about internal cell destruction.

LO2: Outline the functions of the main cell components Vacuole 2 minutes ● Vacuoles are storage bubbles found in cells. They are found in both animal and plant cells but are much larger in plant cells. Vacuoles might store food or any variety of nutrients a cell might need to survive. They can even store waste products so the rest of the cell is protected from contamination. Eventually, those waste products would be sent out of the cell. ● The structure of vacuoles is fairly simple. There is a membrane that surrounds a mass of fluid. In that fluid are nutrients or waste products.