week 1 - bio chem lecture.pdf

2023-09-12 Course Overview BNUR 2003 Biomedical Chemistry & Lab Diagnostics Unit 1- Introduction to biomedical chemistry 1-1 Cell structure and function 1-2 Patient care cycle Professor Ryan Calhoun (Until October 9) Jenna Graham (After October 9) Evaluation 2 Tests Case history assignment* Fina...

2023-09-12 Course Overview BNUR 2003 Biomedical Chemistry & Lab Diagnostics Unit 1- Introduction to biomedical chemistry 1-1 Cell structure and function 1-2 Patient care cycle Professor Ryan Calhoun (Until October 9) Jenna Graham (After October 9) Evaluation 2 Tests Case history assignment* Final group presentation* Final Exam 2x15% 20% 20% 30% *Assignment details, rubric, etc… will be given after groups are formed in Week 2 1 2 Learning Objectives- Cell structure and function The Cell – Introduction Part 1- Organelles 1. Describe the structure and function of the nucleus. 2. Name the organelles of an animal cell and describe their functions. Nucleus Part II- Membrane 1. List the components of the plasma membrane and describe their functions. 2. Explain the various transport mechanisms in biological systems. Cytoplasm = Cytosol + Organelles Plasma membrane 3 4 1 2023-09-12 The Nucleus The Nucleus The nucleus is the control center for cellular operations. -contains (most of) the information needed to synthesize proteins The nuclear envelope is composed of __ membranes.The outside membrane is continuous with the rough endoplasmic reticulum (RER). Functions of the nucleus: • Store genes on chromosomes • Organize genes into chromosomes to allow cell division • Transport via pores • Produce __________ • Produce __________ • Organize uncoiling of DNA for replication 5 6 Organelles- Ribosomes Organelles- Ribosomes Ribosomes coordinate the interaction of ______ and _____ to build polypeptides during protein synthesis. Composed of two subunits, the small ribosomal subunit and the large ribosomal subunit. Free Ribosomes: Scattered through cytoplasm. Manufacture proteins for the cell Free ribosomes (fixed) 7 Fixed Ribosomes: Attached to the ER. Manufacture proteins that enter the endoplasmic reticulum destined for secretion 8 2 2023-09-12 Organelles- Endoplasmic reticulum Organelles- Endoplasmic reticulum 2 1 Free ribosomes (fixed) 3 9 10 Organelles- Endoplasmic reticulum Organelles- Golgi apparatus The endoplasmic reticulum is a network of intracellular membranes connected to the ______________ that synthesize, store, transport, and detoxify molecules. There are two categories of ER: Smooth ER: No ribosomes attached. Synthesizes lipids and carbohydrates. Free ribosomes Rough ER: Ribosomes attached. After synthesis by the ribosomes, proteins are imported into the lumen of the ER for modification and packaging into vesicles. 11 (fixed) 12 3 2023-09-12 Organelles- Golgi apparatus Organelles- Lysosomes The Golgi apparatus is made up of flattened disks and membraneenclosed vesicles. It modifies and packages secretions that are destined for _________ and packages enzymes into vesicles.The Golgi apparatus is involved in lysosome and peroxisome synthesis. Free ribosomes (fixed) 13 Organelles- Lysosomes 14 Organelles- Peroxisomes Lysosomes are membrane-bound vesicles containing digestive Enzymes (include proteases [proteins], nucleases [nucleic acids] glycosidases [CHO] and lipases [lipids]). Needed for ______________ of excess, damaged, and foreign substances. Free ribosomes (fixed) 15 16 4 2023-09-12 Organelles- Peroxisomes Organelles- Mitochondria Peroxisomes are also membrane-bound vesicles.They are roughly spherical and encase oxidative enzymes.They break down fatty acids and organic compounds. In doing so, they produce toxic _____________, but break it down to oxygen and water. Free ribosomes (fixed) 17 Organelles- Mitochondria 18 Organelles- Mitochondria Mitochondria are the powerhouse of the cell. They manufacture most of the cell’s ______ in the citric acid cycle and electron transport chain. Free ribosomes (fixed) 19 20 5 2023-09-12 Organelles- Mitochondria The cytoskeleton is composed of structural proteins that provide strength and structure to the cell. There are three main types of cytoskeletal filaments: • Actin filaments (microfilaments) • Intermediate filaments • Microtubules ____________ combine to form several other organelles: • Cilia and flagella • Centrioles 21 Plasma Membrane Membrane proteins are responsible for most of the functions of the PM. Classification: • Integral vs. Peripheral (Exterior or Interior) • Transmembrane proteins Structure of transmembrane proteins: • Hydrophilic regions vs. hydrophobic regions Plasma Membrane The Plasma Membrane separates the cytoplasm from the extracellular fluid. It has the following functions: • • • • 3 macromolecular components of the plasma membrane: lipids, carbohydrates, proteins 22 Plasma Membrane- Signal transduction The receipt of information signals by a cell is complex. Cells have an extraordinary array of transmembrane proteins called receptors. Receptors act as the antennae of cells. Second messengers (phosphorylated proteins) Single Transducers Growth Factor Receptor DNA RNA Growth Factor Two main functions • Transport – e.g., channels • Communication – e.g., receptors 23 Physical isolation of the cytoplasm and extracellular fluid Regulation and exchange with the environment All PMs have a lipid bilayer The other proteins determine cell function Cytoplasmic Receptor Region (a protein Kinase) m-RNA Proteins 24 6 2023-09-12 Cellular Transport Cellular Transport- Diffusion The plasma membrane is a barrier between the cytoplasm and extracellular fluid. BUT, __________ must get in and waste out. Fortunately, it is selectively permeable. Over time, continuously moving particles will randomly mix. Material moves from areas of high concentration to areas low concentration. Passive transport: No energy required. Active transport: Requires energy in the form of ATP. Simple Diffusion Influenced by distance, molecular size, temperature, gradient size. Major categories of cellular transport: 1. Diffusion (simple and facilitated) 2. Active transport (primary and secondary) 3. Endocytosis and exocytosis 25 26 Cellular Transport- Diffusion Cellular Transport- Osmosis Facilitated diffusion uses membrane ___________________to allow larger and charged molecules to cross the cell membrane. Osmosis is the net diffusion of water over a membrane The speed of facilitated diffusion is limited by the number of channel proteins. 27 28 7 2023-09-12 Cellular Transport-Active transport Cellular Transport-Active transport Certain substances must be pumped across the PM. During active transport energy is used to accomplish transport. In primary active transport energy is used at the membrane protein itself to induce a conformational change that results in transport. In secondary active transport energy is used to establish a concentration gradient. Next the energy of the concentration gradient is used to transport another substance. 29 30 Cellular Transport-Active transport Cellular Transport- Endocytosis and exocytosis In endocytosis and exocytosis, materials that are too large to pass directly through the cell membrane are transported into or out of the cell. Endocytosis Pinocytosis Phagocytosis Exocytosis https://medicoapps.org/glucose-transporters-2/ 31 32 8