Introduction to Cell and Molecular Biology PDF

Introduction to Cell and Molecular Biology Learning Objectives: **MLO1.**   Describe the central dogma of molecular biology. **     MLO2.**   Explain how DNA is transcribed into mRNA, how mRNA is translated into protein and how proteins perform biological functions within cells. **     MLO8.** ...

Introduction to Cell and Molecular Biology Learning Objectives: **MLO1.**   Describe the central dogma of molecular biology. **     MLO2.**   Explain how DNA is transcribed into mRNA, how mRNA is translated into protein and how proteins perform biological functions within cells. **     MLO8.**   Explain, with the aid of diagrams, the key organelles within a cell and how they function. **     MLO9.**   Describe the basic structure of cell membranes and understand its importance in cellular compartmentalisation and maintaining osmolality. Explain the ways in which ions and large molecules are transported across cell membranes. **     MLO15.**   Distinguish between key cell types found within the body and understand how cells form the building blocks of organs and tissues, and relate this to how the body functions as a whole. 'Modern Cell theory' 1. The cell is the basic unit of life 2. All living things are made of one or more cells 3. All new cells arise from pre existing cells by a process of cell division 4. The chemical reactions that create life occur within cells and they all have the same basic chemical composition 5. The activity of an organism depends on the total activity of individual cells 6. Energy flow occurs within cells 7. Cells contain DNA in the chromosome and RNA in the nucleus and cytoplasm 8. All cells in similar organisms are essentially the same in chemical composition Eukaryotic cells include: animal cells, plant cells, fungi Prokaryotic cells include: bacteria, archaea Plasma membrane (E and P) - Maintains a barrier - Regulates movement - Regulates response to signals - Made of phospholipid bilayer of hydrophilic heads and hydrophobic tails Cell wall (E and P, but NOT animal cells) - Determines cell shape - Offers cell protection - Is not metabolically active Cytoplasm - Aqueous, gel like fluid containing salts and various organic molecules - Fluid component is termed cytosol - Membrane bound - Contains DNA in chromosomes, associated with histones - Contains nucleolus - Nuclear pores for communication and transport - Contains cell's genetic material Endoplasmic reticulum - Smooth ER associated with lipid biosynthesis - Rough ER associated with protein synthesis - Transports proteins to Golgi body Ribosomes - Made of protein and rRNA - In (E) 80S ribosomes, in (P) 70S ribosomes - Can aggregate to form polysomes - Site of protein synthesis Golgi Body - Flattened membranous saccules - Accepts and produces vesicles - Post translational modifications and packaging of proteins in vesicles Vesicles - Membrane bound packages of proteins Mitochondria - Inner (cristae) and outer membrane - Contains mitochondrial matrix - Contains ATP synthase - Converts ADP and Pi into ATP - Stores calcium used in cell signalling The endosymbiotic theory is that energy producing organelles in eukaryotic cells originated as primitive aerobic prokaryotes which were engulfed by primitive nucleated cells. Symbiosis meaning -- primitive prokaryotic was offered protection from host cell, and host cell came to rely on prokaryote for energy production and counteracting the toxicity of reactive oxygen species. Cells are specialised for specific functions and there are approx 28-36 trillion cells in the human body. Tissues are a collection of cells with similar structure working together to perform a specific function. The 4 types are: - Epithelial - Connective - Muscle - Nervous Moodle recap quiz Q: The vast majority of a cells genetic information is stored in which organelle? A: Nucleus Q: The rough endoplasmic reticulum is the location of what type of molecule is synthesised? A: Protein Q: Where is ribosomal RNA synthesized? A: Nucleolus Q: Post translational protein modifications occur in which cytoplasmic organelle?\ A: Golgi body Q: Mitochondrial respiration produces which form of cellular energy? A: ATP Q: Where does gene expression take place?\ A: Nucleus