Mammalian Biotechnology Lecture 6 PDF

Week 1 Tue 10th Sept Lecture Module Introduction Week 2 Mon 16th Sept Lecture 1 Use of mammalian cells Tue 17th Sept Lecture 2 Cell Culture Laboratory Lab layout, Equipment and Materials Week 3 Mon 23rd Sept Lecture 3 Cont...

Week 1 Tue 10th Sept Lecture Module Introduction Week 2 Mon 16th Sept Lecture 1 Use of mammalian cells Tue 17th Sept Lecture 2 Cell Culture Laboratory Lab layout, Equipment and Materials Week 3 Mon 23rd Sept Lecture 3 Contamination control Tue 24th Sept Lecture 4 Contamination control Week 4 Mon 30th Sept Lecture 5 Contamination control Tue 01st Oct Lecture 2, 3, 4 and 5 recap and sample assessment questions Week 5 Mon 07th Oct Lecture 6 Nutrient uptake Tue 08th Oct Lecture 7 Nutrient uptake and sample assessment questions Week 6 Mon 14th Oct Lecture 8 Biology of Culture Cells Tue 15th Oct Lecture 9 Cell culture media Week 7 Mon 21st Oct Lecture 10 Cell culture media Tue 22nd Oct Lab 3 data analysis Reading Week Week 8 Mon 04thNov Lecture 11 Cell Culture Media Tue 05 Nov th Lecture 8, 9, 10 and 11 recap and sample assessment questions Week 9 Mon 11th Nov Lecture 12 Growing mammalian cells Tue 12th Nov Lecture 13 Monitoring growth Week 10 Mon 18th Nov Lecture 14 Cryopreservation of cells Tue 19th Nov Lecture 12, 13 and 14 recap and sample assessment questions Week 11 Mon 25th Nov Lecture 15 Innate immune response Tue 26th Nov Lecture 16 Adaptive immune response & Bioassays Lecture 15 and 16 recap and sample assessment questions Week 12 Mon 02nd Dec Revision Tue 03rd Dec BIOT6012 Mammalian Biotechnology Lecture 6 Slide 1  Nutrients - Membrane Transport Lecture Overview Introduction: Why discuss this topic Main discussion: Nutrient uptake mechanisms Conclusion: Take home message BIOT6012 Mammalian Biotechnology Lecture 6 Slide 2  Nutrients - Membrane Transport Introduction Before you can manipulate cells to produce large amounts of desired products or services you need to understand their nutritional requirements BIOT6012 Mammalian Biotechnology Lecture 6 Slide 3  Nutrients - Membrane Transport CARBON ENERGY Backbone of all organic molecules Photoautotrophs and Photoheterotrophs Autotrophs - obtain energy from sunlight - obtain carbon from inorganic molecules like CO2 Chemoautotrophs - obtain energy from reduced Heterotrophs inorganic compounds – obtain carbon from organic matter from other life forms Chemoheterotrophs - obtain energy from hydrogen atoms of organic compounds BIOT6012 Mammalian Biotechnology Lecture 6 Slide 4  Nutrients - Membrane Transport Category Energy Source Carbon Source Example Photoautotroph Sunlight CO2 Photosynthetic organisms such as algae, plants, cyanobacteria. Chemoautotroph Simple inorganic CO2 Only certain chemicals bacteria such as methanogens, deep sea vent bacteria. Photoheterotroph Sunlight Organic Purple and green photosynthetic bacteria. Chemoheterotroph Organic Organic Protozoa, fungi, many bacteria, animals. Saprobe Metabolising the Organic Fungi, bacteria organic matter of (decomposers) dead organisms. Parasite Utilising the Organic Various parasites tissues, fluids of a and pathogens: live host. bacteria, fungi, protozoa, animals. BIOT6012 Mammalian Biotechnology Lecture 6 Slide 5  Nutrients - Membrane Transport Nutrients are required by cells for growth and metabolism and are obtained from the environment. First step in nutrient utilisation is uptake of required nutrients by the cell. The CELL MEMBRANE serves as a selectively permeable barrier and regulates the passage of substances into and out of the cell. Nutrient uptake (i.e., solute transport) is a cellular process for acquiring molecules from the cell environment that are needed to support cell growth, metabolism and cell maintenance. BIOT6012 Mammalian Biotechnology Lecture 6 Slide 6  Nutrients - Membrane Transport To accomplish nutrient uptake, the cell must overcome two major obstacles: 1. The selectively-permeable cytoplasmic membrane - impermeable to many types of molecules. 2. The cell must accumulate each nutrient from a generally low concentration present in the surrounding environment, to a much higher level inside the cell. BIOT6012 Mammalian Biotechnology Lecture 6 Slide 7  Nutrients - Membrane Transport An important function of a biological membrane is to serve as a barrier to the outside world Nutrients must enter the cell and waste products have to leave in order for the cell to survive therefore cell membranes must be selectively permeable e.g. the movement of ions across membranes is important in regulating vital cell characteristics such as cellular pH and osmotic pressure The lipid bilayer presents a formidable barrier to larger and more hydrophilic molecules (such as ions) which must be transported across the membrane by special proteins BIOT6012 Mammalian Biotechnology Lecture 6 Slide 8  Nutrients - Membrane Transport Structure of the Cell Membrane Lipid Bilayer -2 layers of phospholipids a. Phosphate head is polar (water loving) b. Fatty acid tails non-polar (water fearing) c. Proteins embedded in membrane Phospholipid Carbohydrate Lipid Proteins chains Bilayer Transport Phospholipids Protein Fluid Mosaic Model - structural features of the membrane are essential to its functions, such as cellular transport and cell recognition. BIOT6012 Mammalian Biotechnology Lecture 6 Slide 9  Nutrients - Membrane Transport Phospholipids of plasma membrane Amphipathic having both hydrophilic (water-loving) and hydrophobic (water-fearing) regions The hydrophobic core of the plasma membrane helps some materials move through the membrane, while it blocks the movement of others Polar molecules can easily interact with the outer face of the membrane but they have difficulty passing through its hydrophobic core Small ions which are the right size to slip through the membrane cannot do so due to their charge This means that ions like sodium, potassium, calcium, and chloride cannot cross membranes to any significant degree by simple diffusion, and must instead be transported by specialized proteins Larger charged and polar molecules, like sugars and amino acids, also need help from proteins to efficiently cross the membrane BIOT6012 Mammalian Biotechnology Lecture 6 Slide 10  Nutrients - Membrane Transport Proteins – plasma membrane There are many different types of proteins associated with the phospholipid bilayer Some proteins (glycoproteins) have a polysaccharide attached to them. These are important in cell recognition and essential to the immune response. These have a number of roles: - some have pores in them allowing diffusion of small particles - some play a role in facilitated diffusion - some act as enzymes or receptors for hormones - some allow cells to bind together BIOT6012 Mammalian Biotechnology Lecture 6 Slide 11  Nutrients - Membrane Transport Passive Transport (cell doesn’t use energy) 1. Diffusion 2. Osmosis 3. Facilitated Diffusion Active Transport (cell does use energy) 1. Protein Pumps 2. Endocytosis 3. Exocytosis BIOT6012 Mammalian Biotechnology Lecture 6 Slide 12  Nutrients - Membrane Transport Passive Transport Diffusion Diffusion of solute from an area of high concentration to an area of low concentration e.g. glycerol. The external nutrient concentration must be high. No energy required. 220px-Diffusion BIOT6012 Mammalian Biotechnology Lecture 6 Slide 13  Nutrients - Membrane Transport Passive Transport Diffusion Diffusion: The movement of particles from an area of high concentration to an area of low concentration until they spread out evenly (at which point, it’s equally likely for a molecule to move in either direction). BIOT6012 Mammalian Biotechnology Lecture 6 Slide 14  Nutrients - Membrane Transport Passive Transport Diffusion Tendency of a material to spread out Always moves toward equilibrium Net diffusion Net diffusion Equilibrium Net diffusion Net diffusion Equilibrium Equilibrium Net diffusion BIOT6012 Mammalian Biotechnology Lecture 6 Slide 15  Nutrients - Membrane Transport Passive Transport Diffusion Example: Gas exchange: delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs and out of the body. Oxygen crossing red cell membrane HIGH -> low O2 Lungs O2 CO2 CO2 Driving force: concentration gradient Trying to even out concentration BIOT6012 Mammalian Biotechnology Lecture 6 Slide 16  Nutrients - Membrane Transport Passive Transport Osmosis – Diffusion of Water Movement of water from an area of high water potential (low solute concentration) to an area of low water potential (high solute concentration). Membrane permeable to the solvent but not the solute. Important in biological systems. BIOT6012 Mammalian Biotechnology Lecture 6 Slide 17  Nutrients - Membrane Transport Passive Transport Activity Osmosis – Diffusion of Water Describe a hypotonic solution: Consequence for the cell in this solution: BIOT6012 Mammalian Biotechnology Lecture 6 Slide 18  Nutrients - Membrane Transport Passive Transport Activity Osmosis – Diffusion of Water Describe a hypertonic solution: Consequence for the cell in this solution: BIOT6012 Mammalian Biotechnology Lecture 6 Slide 19  Nutrients - Membrane Transport Passive Transport Activity Osmosis – Diffusion of Water Describe an isotonic solution: Consequence for the cell in this solution: BIOT6012 Mammalian Biotechnology Lecture 6 Slide 20  Nutrients - Membrane Transport Conclusion The cell must acquire nutrients from its cell environment to support cell growth, metabolism and cell maintenance The cell membrane serves as a selectively permeable barrier and regulates the passage of substances into and out of the cell including nutrients Passage across the membrane can be passive (no energy) or active (requires energy) Diffusion is typically for nonpolar molecules like CO2 and O2 and small polar molecules like glycerol Osmosis – diffusion of water BIOT6012 Mammalian Biotechnology Lecture 6 Slide 21